ZSH
Section: User Commands (1)
Updated: August 9, 1994
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NAME
zsh - the Z shell
SYNOPSIS
zsh [ ± options ] [ ± o option ] ... [ -c string ] [ arg ... ]
SHELL GRAMMAR
A simple command is a sequence of optional parameter
assignments followed by blank-separated words,
with optional redirections interspersed.
The first word is the command to be executed, and the remaining
words, if any, are arguments to the command.
If a command name is given, the parameter assignments modify
the environment of the command when it is executed.
The value of a simple command is its exit status,
or 128 plus the signal number if terminated by a signal.
If a simple command is preceded by the word exec,
it is executed in the parent shell without forking.
If preceded by command, the command word is taken
to be the name of an external command, rather than a
shell function or builtin.
If preceded by noglob, filename generation is not performed
on any of the words. If preceded by a -, the command
is executed with a - prepended to its argv[0] string.
If preceded by nocorrect, spelling correction is not
done on any of the words.
A pipeline is a sequence of one or more commands
separated by | or |&. |& is shorthand
for 2>&1 |. The standard output of each command is
connected to the standard input of the next command in the
pipeline.
The value of a pipeline is the value of the last command.
If a pipeline is preceded by a !, the value
of that pipeline is the logical NOT of the value of the last
command.
If a pipeline is preceded by coproc, it is
executed as a coprocess; a two-way pipe is established
between it and the parent shell. The shell can read from or write to
the coprocess by means of the >&p and <&p
redirection operators.
A sublist is a sequence of one or more pipelines
separated by && or ||. If two pipelines
are separated by &&, the second pipeline is executed
only if the first is successful (returns a zero value).
If two pipelines are separated by ||, the second is executed
only if the first is unsuccessful (returns a nonzero value). Both
operators have equal precedence and are left associative.
A list is a sequence of one or more sublists
separated by, and optionally terminated by, ;, &,
or a newline.
Normally the shell waits for each list to finish before executing
the next one.
If a list is terminated by a &, the shell executes
it in the background, and does not wait for it to finish.
A complex command is one of the following:
-
- for name [ in word ... ]
-
- do list
-
- done
-
Expand the list of words, and set the parameter
name to each of them in turn, executing
list each time. If the in word is omitted,
use the positional parameters instead of the words.
- for name [ in word ... ] ; sublist
-
This is a shorthand for for.
Though it may cause confusion, it is included for convenience;
its use in scripts is discouraged,
unless sublist is a command of the form { list }.
- foreach name ( word ... )
-
- list
-
- end
-
Another form of for.
- for name in word ...
-
- {
-
- list
-
- }
-
Another form of for.
- for name ( word ... ) {
-
- list
-
- }
-
Another form of for.
- for name ( word ... ) sublist
-
Another form of for.
- select name [ in word ... ]
-
- do list
-
- done
-
Print the set of words, each preceded by a number.
If the in word is omitted, use the positional parameters.
The PROMPT3 prompt is printed and a line is read from standard
input. If this line consists of the number of one of the listed
words, then the parameter name
is set to the word corresponding to this number.
If this line is empty, the selection list is printed again.
Otherwise, the value of the parameter name is set to null.
The contents of the line read from standard input is saved
in the parameter REPLY. list is executed
for each selection until a break or end-of-file is encountered.
- select name [ in word ] ; sublist
-
A short form of select.
- case word in [ pattern ) list ;; ] ... esac
-
Execute the list associated with the first pattern
that matches word, if any. The form of the patterns
is the same as that used for filename generation. See
Filename Generation below.
- case word { [ pattern ) list ;; ] ... }
-
Another form of case.
-
-
if list
- then list
-
- [ elif list ; then list ] ...
-
- [ else list ]
-
- fi
-
The if list is executed, and,
if it returns a zero exit status,
the then list is executed.
Otherwise, the elif list is
executed and, if its value is zero,
the then list is executed.
If each elif list returns
nonzero, the else list is executed.
- if ( list ) sublist
-
A short form of if.
- if ( list ) {
-
- list
-
- } elif ( list ) {
-
- list
-
- } ... else {
-
- list
-
- }
-
An alternate form of if. The parentheses surrounding list can be
omitted if the only command in the list is a conditional expression of the
form [[ exp ]] (see below).
-
-
while list
- do list
-
- done
-
Execute the do list as long as the while list
returns a zero exit status.
- while ( list ) {
-
- list
-
- }
-
An alternate form of while.
-
-
until list
- do list
-
- done
-
Execute the do list as long as until list
returns a nonzero exit status.
-
-
repeat word
- do list
-
- done
-
word is expanded and treated as an arithmetic expression,
which must evaluate to a number n.
list is then executed n times.
- repeat word sublist
-
This is a short form of repeat.
- ( list )
-
Execute list in a subshell.
- { list }
-
Execute list.
-
-
function word [ () ] ... { list }
- word ... () { list }
-
- word ... () sublist
-
Define a function which is referenced by any one of word.
Normally, only one word is provided; multiple words
are usually only useful for setting traps.
The body of the function is the list between
the { and }.
See FUNCTIONS below.
- time [ pipeline ]
-
The pipeline is executed, and timing statistics are
reported on the standard error in the form specified
by the TIMEFMT parameter.
If pipeline is omitted, print statistics about the
shell process and its children.
- [[ exp ]]
-
Evaluates the conditional expression exp
and return a zero exit status if it is true.
See Conditional Expressions below for a description
of exp.
RESERVED WORDS
The following words are recognized as reserved words when used
as the first word of a command
unless quoted or removed using the unalias builtin:
-
do done esac then elif else fi for case
if while function repeat time until exec command
select coproc noglob - nocorrect foreach end
COMMENTS
In noninteractive shells, or in interactive shells with the
INTERACTIVE_COMMENTS option set, a word beginning
with the third character of the HISTCHARS parameter
(`#' by default) causes that word and all the following
characters up to a newline to be ignored.
ALIASING
Every token in the shell input is checked to see if there
is an alias defined for it.
If so, it is replaced by the text of the alias if it is in command
position (if it could be the first word of a simple command),
or if the alias is global.
If the text ends with a space, the next word in the shell input
is treated as though it were in command position for purposes of alias
expansion.
An alias is defined using the alias builtin; global aliases
may be defined using the -g option to that builtin.
Alias substitution is done on the shell input before any
other substitution except history substitution. Therefore,
if an alias is defined for the word foo, alias substitution
may be avoided by quoting part of the word, e.g. \foo.
But there is nothing to prevent an alias being defined
for \foo as well.
QUOTING
A character may be quoted (that is, made
to stand for itself) by preceding it with a \.
\ followed by a newline is ignored.
All characters enclosed between a pair of single quotes ('')
are quoted, except the first character of HISTCHARS ( `!' by default).
A single quote cannot appear within single quotes.
Inside double quotes (""), parameter and command substitution
occurs, and \ quotes the characters \, `, ", and $.
EXPANSION
Expansion is performed on the command line after it has been
parsed. The types of expansions performed are
filename expansion,
process substitution,
parameter expansion,
command substitution,
arithmetic expansion,
brace expansion,
and filename generation.
Filename Expansion
Each word is checked to see if it begins with an unquoted ~.
If it does, then the word up to a / is checked to see if it matches
the name of a named directory. If so, then the ~ and the matched portion
are replaced with the value of the named directory.
A ~ by itself or followed by a / is replaced by the value of the
HOME parameter.
A ~ followed by a + or a - is replaced by the value of
PWD or OLDPWD, respectively.
Named directories are typically login directories for users on the system.
They may also be defined if the text after the ~ is the name
of a string shell parameter whose value begins with a /.
In certain circumstances (in prompts, for instance), when the shell
prints a path, the path is checked to see if it has a named
directory as its prefix. If so, then the prefix portion
is replaced with a ~ followed by the name of the directory.
The longest match is preferred.
If a word begins with an unquoted = and the
NO_EQUALS option is not set,
the remainder of the word is taken as the
name of a command or alias. If a command
exists by that name, the word is replaced
by the full pathname of the command.
If an alias exists by that name, the word
is replaced with the text of the alias.
Otherwise the word is checked up to a /
to see if it is a number or a -. If so,
the matched portion is replaced with
the nth directory in the directory stack,
where n is the number matched, or
the last directory in the directory stack
if a - is matched.
Filename expansion is performed on the right hand side of a parameter
assignment, including those appearing after commands of the
typeset family. In this case, the right hand side will be treated
as a colon-separated list in the manner of PATH so that a ~ or an
= following a : is eligible for expansion. All such behavior can be
disabled by quoting the ~, the =, or the whole expression (but not
simply the colon); the NO_EQUALS option is also respected.
If the option MAGIC_EQUAL_SUBST is set, any unquoted shell
argument in the form identifier=expression becomes eligible
for file expansion as described in the previous paragraph. Quoting the
first = also inhibits this.
Process Substitution
Each command argument of the form
<(list)
or
>(list)
or
=(list)
is subject to process substitution.
In the case of the
<
or
>
forms, the shell will run process
list
asynchronously connected to a named pipe (FIFO).
The name of this pipe will become the argument to the command.
If the form with
>
is selected then writing on this file will provide input for
list.
If
<
is used,
then the file passed as an argument will
be a named pipe connected to the output of the
list
process.
For example,
-
paste <(cut -f1 file1) <(cut -f3 file2) | tee >(process1) >(process2) >/dev/null
cuts
fields 1 and 3 from
the files
file1
and
file2
respectively,
pastes
the results together, and sends it to the processes
process1
and
process2.
Note that the file, which is passed as an argument to the command,
is a system
pipe
so programs that expect to
lseek(2)
on the file will not work.
Also note that the previous example can be more compactly and
efficiently written as:
-
paste <(cut -f1 file1) <(cut -f3 file2) > >(process1) > >(process2)
The shell uses pipes instead of FIFOs to implement the latter
two process substitutions in the above example.
If
=
is used,
then the file passed as an argument will be the name
of a temporary file containing
the output of the
list
process. This may be used instead of the
<
form for a program that expects to lseek(2) on the input file.
Parameter Expansion
The character $ is used to introduce parameter expansions.
See PARAMETERS below for a description of parameters.
-
- ${name}
-
The value, if any, of the parameter name is substituted.
The braces are required if name is followed by
a letter, digit, or underscore that is not to be interpreted
as part of its name.
If name is an array parameter, then the values of each
element of name is substituted, one element per word.
Otherwise, the expansion results in one word only; no
word splitting is done on the result.
- ${+name}
-
If name is the name of a set parameter `1' is substituted,
otherwise `0' is substituted.
- ${name:-word}
-
If name is set and is non-null then substitute its
value; otherwise substitute word.
- ${name:=word}
-
If name is unset or is null then
set it to word; the value of the parameter is then
substituted.
- ${name:?word}
-
If name is set and is non-null, then substitute
its value; otherwise, print word and exit from the shell.
If word is omitted, then a standard message is printed.
- ${name:+word}
-
If name is set and is non-null then substitute
word; otherwise substitute nothing.
- ${name#pattern}
-
- ${name##pattern}
-
If the pattern matches the beginning of the value of
name, then substitute the value of name with
the matched portion deleted; otherwise, just
substitute the value of name. In the first
form, the smallest matching pattern is preferred;
in the second form, the largest matching pattern is preferred.
- ${name%pattern}
-
- ${name%%pattern}
-
If the pattern matches the end of the value of
name, then substitute the value of name with
the matched portion deleted; otherwise, just
substitute the value of name. In the first
form, the smallest matching pattern is preferred;
in the second form, the largest matching pattern is preferred.
- ${#spec}
-
If spec is one of the above substitutions, substitute
the length in characters of the result instead of
the result itself. If spec is an array expression,
substitute the number of elements of the result.
- ${^spec}
-
Toggle the value of the RC_EXPAND_PARAM option for the
evaluation of spec.
When this option is set, array expansions of the form
foo${xx}bar, where the parameter
xx is set to (a b c), are substituted with
fooabar foobbar foocbar instead of the default
fooa b cbar.
- ${=spec}
-
Toggle the value of the SH_WORD_SPLIT option for the
evaluation of spec.
When this option is set, parameter values are split into
separate words using IFS as a delimiter
before substitution.
This is done by default in most other shells.
- ${~spec}
-
Toggle the value of the CSH_JUNKIE_TILDE option for the evaluation
of spec. When this option is set, any = and ~ resulting from
the substitution become eligible for file expansion.
If the colon is omitted from one of the above expressions
containing a colon, then the shell only checks whether
name is set or not, not whether it is null.
If the opening brace is directly followed by an opening parentheses
the string up to the matching closing parentheses will be taken as a
list of flags, where the following are supported:
-
- o
-
the resulting words will be sorted in ascending order
- O
-
the resulting words will be sorted in descending order
- i
-
if given together with o or O makes the sort be case
independent
- L
-
convert the result to all lower case
- U
-
convert the result to all upper case
- C
-
capitalize the resulting words
- c
-
if using ${#name} to count array elements, this flag makes
it count characters (as if the elements were concatenated with spaces
between them)
- w
-
like c, but works for strings and arrays and makes the shell
count words (words are strings separated by white spaces or by the
string given with the s flag)
- l:expr::string1::string2:
-
specifies a left padding for the resulting words; each word will be
placed in a field expr characters wide (truncated if needed),
the space to the left will be filled with string1 (concatenated
as often, as needed) or spaces if string1 is not given; if both
string1 and string2 are given, this string will be placed
exactly once
directly to the left of the resulting word. Any character (or the
pairs `(...)', `{...}', `[...]', or `<...>') can be used
instead of the colon to enclose the arguments.
- r:expr::string1::string2:
-
like l..., but for right padding
- j:string:
-
if SH_WORD_SPLIT is set, the resulting words will be
concatenated with this string and then split again at the
string given with the s flag; if neither j nor s are
given this will be done with spaces.
- s:string:
-
see above
- S
-
this one and all following flags are used with the ${...#...} or
${...%...} forms;
this one makes them search substrings, too, not only beginnings or ends
- I:expr:
-
makes them search the n'th match (if expr evaluates to n)
- M
-
include the matched portion in the result
- R
-
include the unmatched portion in the result (the rest)
- B
-
include the index of the beginning of the match in the result
- E
-
include the index of the end of the match in the result
- N
-
include the length of the match in the result
Command Substitution
A command enclosed in parentheses
preceded by a dollar sign, like so: $(...) or quoted with grave
accents: `...` is replaced with its standard output.
If the substitution is not enclosed in double quotes, the
output is broken into words using the IFS parameter.
The substitution $(cat foo) may be replaced
by the equivalent but faster $(<foo).
Arithmetic Expansion
A string of the form $[exp] is substituted
with the value of the arithmetic expression exp.
See ARITHMETIC EVALUATION below.
Brace Expansion
A string of the form
foo{xx,yy,zz}bar
is expanded to the individual words
fooxxbar, fooyybar, and foozzbar.
Left-to-right order is preserved. This construct
may be nested. Malformed brace expansion expressions,
including expressions without a comma, are left unchanged
by the shell.
An expression of the form
{x-y},
where x and y are single characters,
is expanded to every character between
x and y, inclusive.
Filename Generation
If a word contains an unquoted instance of one of the characters
*, |, <, [, or ?, it is regarded
as a pattern for filename generation, unless the NO_GLOB option is set.
If the EXTENDED_GLOB option is set, the
^, ~ and # characters also denote a pattern; otherwise
(except for an initial ~, see Filename Expansion above)
they are not treated specially by the shell.
The word is replaced with a list of sorted filenames that match
the pattern. If no matching pattern is found, the shell gives
an error message, unless the NULL_GLOB option is set,
in which case the word is deleted; or unless the NO_NOMATCH
option is set, in which case the word is left unchanged.
In filename generation,
the character / must be matched explicitly; also, a . must be matched
explicitly at the beginning of a pattern or after a /, unless the
GLOB_DOTS option is set. No filename generation pattern
matches the files "." or "..". In other instances of pattern
matching, the / and . are not treated specially.
-
- *
-
matches any string, including the null string.
- ?
-
matches any character.
- [ ... ]
-
matches any of the enclosed characters.
- [^ ... ]
-
matches any character except the enclosed characters.
[! ... ]
is the same as the above.
- <x-y>
-
matches any number in the range x to y, inclusive.
If x is omitted, the number must be less than or equal to y.
If y is omitted, the number must be greater than or equal to x.
A pattern of the form <-> or
simply <> matches any number.
- ^x
-
matches anything except the pattern x.
- x|y
-
matches either x or y.
- x#
-
matches zero or more occurrences of the pattern x.
- x##
-
matches one or more occurrences of the pattern x.
Parentheses may be used for grouping. Note that the | character
must be within parentheses, so that the lexical analyzer does
not think it is a pipe character. Also note that "/" has a
higher precedence than "^"; that is:
-
ls
^foo/bar
will search directories in "." except "./foo" for a file named bar.
A pathname component of the form
(foo/)#
matches a path consisting of zero or more directories
matching the pattern foo.
As a shorthand,
**/
is equivalent to
(*/)#.
Thus:
-
ls
(*/)#bar
or
-
ls
**/bar
does a recursive directory search for files named bar.
If used for filename generation, a pattern may contain an exclusion
specifier. Such patterns are of the form pat1~pat2.
This pattern will generate all files matching pat1, but which
do not match pat2. For example, *.c~lex.c will match
all files ending in .c, except the file lex.c.
Patterns used for filename generation may also end in a
list of qualifiers enclosed in parentheses.
The qualifiers
specify which filenames that otherwise match the given pattern
will be inserted in the argument list.
A qualifier may be any one of the following:
-
- /
-
directories
- .
-
plain files
- @
-
symbolic links
- =
-
sockets
- p
-
named pipes (FIFOs)
- *
-
executable plain files (0100)
- %
-
device files (character or block special)
- %b
-
block special files
- %c
-
character special files
- r
-
readable files (0400)
- w
-
writable files (0200)
- x
-
executable files (0100)
- R
-
world-readable files (0004)
- W
-
world-writable files (0002)
- X
-
world-executable files (0001)
- s
-
setuid files (04000)
- S
-
setgid files (02000)
- ddev
-
files on the device dev
- l[-|+]ct
-
files having a link count less than ct (-), greater than
ct (+), or is equal to ct
- U
-
files owned by the effective user id
- G
-
files owned by the effective group id
- uid
-
files owned by user id id if it is a number, if not, than the
character after the u will be used as a separator and the string
between it and the next matching separator (`(', `[', `{', and `<'
match `)', `]', `}', and `>' respectively, any other character matches
itself) will be taken as a user name and the user id of this user will
be taken (e.g. u:foo: or u[foo] for user foo)
- gid
-
like uid but with group ids or names
- a[-|+]n
-
files accessed within last n days (-), more than n days
ago (+), or n days ago
- m[-|+]n
-
files modified within last n days (-), more than n days
ago (+), or n days ago
- c[-|+]n
-
files whose inode changed within last n days (-), more than
n days ago (+), or n days ago.
If any of the flags a, m, or c is directly followed by a
M, w, h, or m (e.g. mh+5) the check is
performed with months (of 30 days), weeks, hours, or minutes instead
of days, respectively.
- L[+|-]n
-
files less than n bytes (-), more than n bytes (+), or
exactly n bytes in length.
- ^
-
negates all qualifiers following it
- -
-
toggles between making the qualifiers work on symbolic links (the
default) and the files they point to
- M
-
sets the MARK_DIRS option for the current pattern
- T
-
appends a traling qualifier mark to the file names, analogous to the
LIST_TYPES option, for the current pattern (overrides M)
- N
-
sets the NULL_GLOB option for the current pattern
- D
-
sets the GLOB_DOTS option for the current pattern
More than one of these lists can be combined, separated by commas. The
whole list matches if at least one of the sublists matches (they are
`or'ed', the qualifiers in the sublists are `and'ed').
If a : appears in a qualifier list, the remainder of the expression in
parenthesis is interpreted as a modifier (see the subsection
Modifiers of the section HISTORY). Note that each modifier
must be introduced by a separate :. Note also that the result after
modification does not have to be an existing file. The name of any
existing file can be followed by a modifier of the form (:..) even if no
filename generation is performed.
Thus:
-
ls
*(-/)
lists all directories and symbolic links that point to directories,
and
-
ls
*(%W)
lists all world-writable device files in the current directory,
and
-
ls
*(W,X)
lists all files in the current directory that are
world-writable or world-executable, and
-
echo
/tmp/foo*(u0^@:t)
outputs the basename of all root-owned files beginning with the string
"foo" in /tmp, ignoring symlinks, and
-
ls
*.*~(lex|parse).[ch](^D^l1)
lists all files having a link count of one whose names contain a dot
(but not those starting with a dot, since GLOB_DOTS is explicitly
switched off) except for lex.c, lex.h, parse.c, and parse.h.
A "/" at the end of a pattern
is equivalent to "(/)".
REDIRECTION
Before a command is executed, its input and output
may be redirected.
The following may appear anywhere in a simple command
or may precede or follow a complex command.
Substitution occurs before
word
is used except as noted below.
If the result of substitution on
word
produces more than one filename,
redirection occurs for each
separate filename in turn.
- <word
-
Open file
word
as standard input.
- >word
-
Open file
word
as standard output.
If the file does not exist then it is created.
If the file exists, and the
NO_CLOBBER
option is set,
this causes an error;
otherwise, it is truncated to zero length.
- >! word
-
Same as
>,
except that the file is truncated to zero length
if it exists, even if
NO_CLOBBER
is set.
- >>word
-
Open file
word
as standard output.
If the file exists then output is appended to it.
If the file does not exist, and the
NO_CLOBBER
option is set,
this causes an error;
otherwise, the file is created.
- >>! word
-
Same as
>>,
except that the file is created if it does not
exist, even if
NO_CLOBBER
is set.
- <<[-] word
-
The shell input is read up to a line that is the same as
word,
or to an end-of-file.
No parameter substitution, command substitution or
filename generation is performed on
word.
The resulting document,
called a
here-document,
becomes
the standard input.
If any character of word is quoted with
single or double quotes or a \,
no interpretation
is placed upon the characters of the document.
Otherwise, parameter and command substitution
occurs, \ followed by a newline is removed,
and \ must be used to quote the characters
\, $, `, and the first character of word.
If <<- is used, then all leading
tabs are stripped from word and from the document.
- <<<word
-
Open a file containing word, after expansion,
as standard input.
- <&digit
-
The standard input
is duplicated from file descriptor
digit
(see
dup(2)).
Similarly for standard output using
>&digit.
- >&word
-
Same as
>word
2>&1.
- >>&word
-
Same as
>>word
2>&1.
- <&-
-
Close the standard input.
- >&-
-
Close the standard output.
- <&p
-
The input from the coprocess is moved to the standard input.
- >&p
-
The output to the coprocess is moved to the standard output.
If one of the above is preceded by a digit, then the file
descriptor referred to is that specified by the digit
(instead of the default 0 or 1).
The order in which redirections are specified is significant.
The shell evaluates each redirection in terms of the
(file descriptor, file)
association at the time of evaluation.
For example:
-
... 1>fname 2>&1
first associates file descriptor 1 with file
fname.
It then associates file descriptor 2 with the file associated with file
descriptor 1 (that is,
fname).
If the order of redirections were reversed, file descriptor 2 would be associated
with the terminal (assuming file descriptor 1 had been) and then file descriptor
1 would be associated with file
fname.
If the user tries to open a file descriptor for writing more than once,
the shell opens the file descriptor as a pipe to a process that copies
its input to all the specified outputs, similar to tee(1). Thus:
-
date >foo >bar
writes the date to two files, named "foo" and "bar".
Note that a pipe is an implicit indirection; thus
-
date >foo | cat
writes the date to the file "foo", and also pipes it to cat.
If the user tries to open a file descriptor for reading more than once,
the shell opens the file descriptor as a pipe to a process that copies
all the specified inputs to its output in the order
specified, similar to cat(1). Thus
-
sort <foo <fubar
or even
-
sort <f{oo,ubar}
is equivalent to "cat foo bar | sort". Similarly, you can do
-
echo exit 0 >> *.sh
Note that a pipe is in implicit indirection; thus
-
cat bar | sort <foo
is equivalent to "cat bar foo | sort" (note the order of the inputs).
If a simple command consists of one or more redirection operators
and zero or more parameter assignments, but no command name,
the command cat is assumed. Thus
-
< file
prints the contents of file.
If a command is followed by
&
and job control is not active,
then the default standard input
for the command
is the empty file
/dev/null.
Otherwise, the environment for the execution of a command contains the
file descriptors of the invoking shell as modified by
input/output specifications.
COMMAND EXECUTION
If a command name contains no slashes, the shell attempts to locate
it. If there exists a shell function by that name, the function
is invoked as described below in FUNCTIONS. If there exists
a shell builtin by that name, the builtin is invoked.
Otherwise, the shell searches each element of path for a
directory containing an executable file by that name. If the
search is unsuccessful, the shell prints an error message and returns
a nonzero exit status.
If execution fails because the file is not in executable format,
and the file is not a directory, it is assumed to be a shell
script. /bin/sh is spawned to execute it. If the program
is a file beginning with #!, the remainder of the first line
specifies an interpreter for the program. The shell will
execute the specified interpreter on operating systems that do
not handle this executable format in the kernel.
FUNCTIONS
The
function
reserved word is used to define shell functions.
Shell functions are read in and stored internally.
Alias names are resolved when the function is read.
Functions are executed like commands with the arguments
passed as positional parameters.
(See
Execution
below).
Functions execute in the same process as the caller and
share all files
and present working directory with the
caller.
A trap on
EXIT
set inside a function
is executed after the function completes in the environment
of the caller.
The
return
builtin is used to return
from function calls.
Function identifiers
can be listed with the
functions
builtin.
Functions can be undefined with the
unfunction
builtin.
The following functions, if defined, have special meaning to
the shell:
- chpwd
-
Executed whenever the current working directory is changed.
- precmd
-
Executed before each prompt.
- periodic
-
If the parameter
PERIOD
is set, this function is executed every
PERIOD
seconds, just before a prompt.
- TRAPxxx
-
If defined and non-null,
this function will be executed whenever the shell
catches a signal SIGxxx, where xxx is a signal
name as specified for the kill builtin (see below).
The signal number will be passed as the first parameter to the function.
In addition, TRAPZERR is executed whenever a command has a non-zero
exit status, TRAPDEBUG is executed after each command, and
TRAPEXIT
is executed when the shell exits,
or when the current function exits if defined
inside a function.
If a function of this form is defined and null,
the shell and processes spawned by it will ignore SIGxxx.
JOBS
If the
MONITOR
option is set,
an interactive shell associates a job with each pipeline.
It keeps
a table of current jobs, printed by the
jobs
command, and assigns them small integer numbers.
When a job is started asynchronously with
&,
the shell prints a line which looks
like:
[1] 1234
indicating that the job which was started asynchronously was job number
1 and had one (top-level) process, whose process id was 1234.
If you are running a job and wish to do something else you may hit the key
^Z (control-Z) which sends a TSTP signal to the current job.
The shell will then normally indicate that the job has been `suspended',
and print another prompt.
You can then manipulate the state of this job,
putting it in the background with the
bg
command, or run some other
commands and then eventually bring the job back into the foreground with
the foreground command
fg.
A ^Z takes effect immediately and
is like an interrupt in that pending output and unread input are discarded
when it is typed.
A job being run in the background will suspend if it tries to read
from the terminal.
Background jobs are normally allowed to produce output,
but this can be disabled by giving the command ``stty tostop''.
If you set this
tty option, then background jobs will suspend when they try to produce
output like they do when they try to read input.
There are several ways to refer to jobs in the shell.
A job can be referred to by the process id of any process of the job
or by one of the following:
- %number
-
The job with the given number.
- %string
-
Any job whose command line begins with
string.
- %?string
-
Any job whose command line contains
string.
- %%
-
Current job.
- %+
-
Equivalent to
%%.
- %-
-
Previous job.
The shell learns immediately whenever a process changes state.
It normally informs you whenever a job becomes blocked so that
no further progress is possible. If
notify
is not set, it waits until
just before it prints
a prompt before it informs you.
When the monitor mode is on, each background job that completes
triggers any trap set for
CHLD.
When you try to leave the shell while jobs are running or suspended, you will
be warned that `You have suspended (running) jobs.'
You may use the
jobs
command to see what they are.
If you do this or immediately try to
exit again, the shell will not warn you a second time; the suspended
jobs will be terminated, and the running jobs will be sent
a SIGHUP signal.
To avoid having the shell terminate the running jobs, either
use the nohup(1) command or the disown builtin (see below).
SIGNALS
The INT and QUIT signals for an invoked
command are ignored if the command is followed by
&
and the job
MONITOR
option is not active.
Otherwise, signals have the values
inherited by the shell from its parent
(but see the TRAPxxx special function above).
HISTORY
History substitution allows you to use words from previous command
lines in the command line you are typing. This simplifies spelling
corrections and the repetition of complicated commands or arguments.
Command lines are saved in the history list, the size of which
is controlled by the
HISTSIZE
variable. The most recent command is retained in any case.
A history substitution begins with a
!
and may occur anywhere on the command line; history
substitutions do not nest. The
!
can be escaped with
\
to suppress its special meaning.
Single or double quotes will not work for this.
Input lines containing history substitutions are echoed on the
terminal after being expanded, but before any other
substitutions take place or the command gets executed.
Event Designators
An event designator is a reference to a command-line entry in
the history list.
-
- !
-
Start a history substitution, except when followed by a blank, newline,
=,
or
(.
- !!
-
Refer to the previous command.
By itself, this substitution
repeats the previous command.
- !n
-
Refer to command-line
n.
- !-n
-
Refer to the current command-line minus
n.
- !str
-
Refer to the most recent command starting with
str.
- !?str[?]
-
Refer to the most recent command containing
str.
- !#
-
Refer to the current command line typed in so far.
- !{...}
-
Insulate a history reference from adjacent characters (if necessary).
Word Designators
A word designator indicates which word or words of a given command line will
be included in a history reference. A
`:'
separates the event specification from the word designator.
It can be omitted if the word designator begins with a
^,
$,
*,
-
or
%.
Word designators include:
-
- 0
-
The first input word (command).
- n
-
The
n'th
argument.
- ^
-
The first argument, that is,
1.
- $
-
The last argument.
- %
-
The word matched by (the most recent)
?str
search.
- x-y
-
A range of words;
-y
abbreviates
0-y.
- *
-
All the arguments, or a null value if there is just
one word in the event.
- x*
-
Abbreviates
x-$.
- x-
-
Like
x*
but omitting word
$.
Note that a
`%'
word designator will only work when used as
!%,
!:%,
!?str?:%
and only when used after a !? substitution. Anything else will result
in an error, although the error may not be the most obvious one.
Modifiers
After the optional word designator, you can add
a sequence of one or more of the following modifiers,
each preceded by a
:.
These modifiers also work on the result
of filename and parameter expansion.
-
- h
-
Remove a trailing pathname component, leaving the head.
- r
-
Remove a trailing suffix of the form
`.xxx',
leaving the basename.
- e
-
Remove all but the suffix.
- t
-
Remove all leading pathname components, leaving the tail.
- &
-
Repeat the previous substitution.
- g
-
Apply the change to the first occurrence of a match in each word,
by prefixing the above (for example,
g&).
- p
-
Print the new command but do not execute it.
- q
-
Quote the substituted words, escaping further substitutions.
- x
-
Like
q,
but break into words at each blank.
- l
-
Convert the words to all lowercase.
- u
-
Convert the words to all uppercase.
- f
-
Repeats the immediately (without a colon) following modifier until the
resulting word doesn't change any more. This one and the following
four only work with parameter and filename expansion.
- F:expr:
-
Like f, but repeats only n times if the expression
expr evaluates to n. Any character can be used instead of
the `:', if any of `(', `[', or `{' is used as the opening delimiter
the second one has to be ')', `]', or `}' respectively.
- w
-
Makes the immediately following modifier work on each word in the
string.
- W:sep:
-
Like w but words are considered to be the parts of the string
that are separated by sep. Any character can be used instead of
the `:', opening parentheses are handled specially, see above.
- s/l/r[/]
-
Substitute
r
for
l.
Unless preceded by a
g,
the substitution is done only for the
first string that matches
l.
The left-hand side of substitutions are not regular expressions,
but character strings.
Any character can be used as the delimiter in place of
/.
A backslash quotes the delimiter character.
The character
&,
in the right hand side, is replaced by the text
from the left-hand-side.
The
&
can be quoted with a backslash.
A null
l
uses the previous string either from a
l
or from a contextual scan string
s
from
!?s.
You can omit the rightmost delimiter if a newline
immediately follows
r;
the rightmost
?
in a context scan can similarly be omitted.
By default, a history reference with no event specification refers to the same
line as the last history reference on that command line, unless it is the
first history reference in a command. In that case, a history reference
with no event specification always refers to the previous command. However,
if the option CSH_JUNKIE_HISTORY is set, then history reference with no
event specification will always refer to the previous command.
For example,
!!:1
will always refer to the first word of the previous command and
!!$
will always refer to the last word of the previous command. And with
CSH_JUNKIE_HISTORY set, then
!:1
and
!$
will function in the same manner as
!!:1
and
!!$,
respectively. However, if CSH_JUNKIE_HISTORY is unset, then
!:1
and
!$
will refer to the first and last words respectively, of the last command
referenced on the current command line. However, if they are the first history
reference on the command line, then they refer to the previous command.
The character sequence
^foo^bar
repeats the last command, replacing the string "foo" with the
string "bar".
If the shell encounters the character sequence
!"
in the input, the history mechanism is temporarily disabled until
the current list is fully parsed. The
!"
is removed from the input, and any subsequent
!
characters have no special significance.
A less convenient but more comprehensible
form of command history support
is provided by the
fc
builtin (see below).
ARITHMETIC EVALUATION
An ability to perform integer arithmetic
is provided with the builtin
let.
Evaluations are performed using
long
arithmetic.
Constants are of the form
[base#]n
where
base
is a decimal number between two and thirty-six
representing the arithmetic base
and
n
is a number in that base (for example, `16#ff' is 255 in hexadecimal).
If
base
is omitted
then base 10 is used. For backwards compatibility the form `[16]ff'
is also accepted.
An arithmetic expression uses nearly the same syntax, precedence, and
associativity of
expressions in C.
The following operators are supported (listed in decreasing order
of precedence):
-
- + - ! ~ ++ --
-
unary plus/minus, logical NOT, complement, {pre,post}{in,de}crement
- &
-
logical AND
- ^
-
logical XOR
- |
-
logical OR
- * / % **
-
multiplication, division, remainder, exponentiation
- + -
-
addition, subtraction
- << >>
-
logical shift left, shift right
- < > <= >=
-
comparison
- == !=
-
equality and inequality
- &&
-
boolean AND
- || ^^
-
boolean OR, XOR
- ? :
-
ternary operator
- = += -= *= /= %= &= ^= |= <<= >>= &&= ||= ^^= **=
-
assignment
- ,
-
comma operator
The operators &&, ||, &&=, and ||= are short-circuiting,
and only one of the latter two expressions in a ternary operator
is evaluated. Note the precedence of the logical AND, OR,
and XOR operators.
An expression of the form #\x where x is any character
gives the ascii value of this character and an expression of the form
#foo gives the ascii value of the first character of the value
of the parameter foo.
Named parameters can be referenced by name within an arithmetic expression
without using the parameter substitution syntax, but if it is an array
with a subscript the leading $ is needed.
An internal integer representation of a named parameter
can be specified with the
integer
builtin.
Arithmetic evaluation is performed on the value of each
assignment to a named parameter declared integer
in this manner.
Since many of the arithmetic operators require
quoting, an alternative form of the
let
command is provided.
For any command which begins with a
((,
all the characters until a matching
))
are treated as a quoted expression.
More precisely,
((...))
is equivalent to
let
"...".
CONDITIONAL EXPRESSIONS
A conditional expression is used with the
[[
compound command to test attributes of files and to compare strings.
Each expression can be constructed from one or more
of the following unary or binary expressions:
- -a file
-
true if
file
exists.
- -b file
-
true if
file
exists and is a block special file.
- -c file
-
true if
file
exists and is a character special file.
- -d file
-
true if
file
exists and is a directory.
- -e file
-
true if
file
exists.
- -f file
-
true if
file
exists and is an ordinary file.
- -g file
-
true if
file
exists and has its setgid bit set.
- -h file
-
true if
file
exists and is a symbolic link.
- -k file
-
true if
file
exists and has its sticky bit set.
- -n string
-
true if length of
string
is non-zero.
- -o option
-
true if option named
option
is on.
- -p file
-
true if
file
exists and is a fifo special file or a pipe.
- -r file
-
true if
file
exists and is readable by current process.
- -s file
-
true if
file
exists and has size greater than zero.
- -t fd
-
true if file descriptor number
fd
is open and associated with a terminal device.
(note: fd is not optional)
- -u file
-
true if
file
exists and has its setuid bit set.
- -w file
-
true if
file
exists and is writable by current process.
- -x file
-
true if
file
exists and is executable by current process.
If
file
exists and is a directory, then the current process
has permission to search in the directory.
- -z string
-
true if length of
string
is zero.
- -L file
-
true if
file
exists and is a symbolic link.
- -O file
-
true if
file
exists and is owned by the effective user id of this process.
- -G file
-
true if
file
exists and its group matches the effective group id of this process.
- -S file
-
true if
file
exists and is a socket.
- file1 -nt file2
-
true if
file1
exists and is newer than
file2.
- file1 -ot file2
-
true if
file1
exists and is older than
file2.
- file1 -ef file2
-
true if
file1
and
file2
exist and refer to the same file.
- string = pattern
-
true if
string
matches
pattern.
- string != pattern
-
true if
string
does not match
pattern.
- string1 < string2
-
true if
string1
comes before
string2
based on ASCII value of their characters.
- string1 > string2
-
true if
string1
comes after
string2
based on ASCII value of their characters.
- exp1 -eq exp2
-
true if
exp1
is equal to
exp2.
- exp1 -ne exp2
-
true if
exp1
is not equal to
exp2.
- exp1 -lt exp2
-
true if
exp1
is less than
exp2.
- exp1 -gt exp2
-
true if
exp1
is greater than
exp2.
- exp1 -le exp2
-
true if
exp1
is less than or equal to
exp2.
- exp1 -ge exp2
-
true if
exp1
is greater than or equal to
exp2.
- ( exp )
-
true if exp is true.
- ! exp
-
true if exp is false.
- exp1 && exp2
-
true if exp1 and exp2 are both true.
- exp1 || exp2
-
true if either exp1 or exp2 is true.
In each of the above expressions, if
file
is of the form
/dev/fd/n,
where
n
is an integer,
then the test applied to the open file whose
descriptor number is
n,
even if the underlying system does not support
the /dev/fd directory.
ZSH LINE EDITOR
If the ZLE option is set (it is by default)
and the shell input is attached to the terminal, the user
is allowed to edit command lines.
There are two display modes. The first, multiline mode, is the
default. It only works if the TERM parameter is set to a valid
terminal type that can move the cursor up. The second, single line
mode, is used if TERM is invalid or incapable of moving the
cursor up, or if the SINGLE_LINE_ZLE option is set. This mode
is similar to ksh, and uses no termcap sequences. If TERM is
"emacs", the ZLE option will be unset by the shell.
Bindings
Command bindings may be set using the bindkey builtin.
There are two keymaps-the main keymap and the alternate keymap.
The alternate keymap is bound to vi command mode.
The main keymap is bound to emacs mode by default.
To bind the main keymap to vi insert mode, use
bindkey -v. However, if one of the VISUAL or
EDITOR environment variables contain the string vi when the shell
starts up the main keymap will be bound to vi insert mode by default.
The following is a list of all the key commands
and their default bindings in emacs and vi command mode.
Movement
- vi-backward-blank-word (unbound) (B)
-
Move backward one word, where a word is defined as a series of
non-blank characters.
- backward-char (^B ESC-[D) ()
-
Move backward one character.
- vi-backward-char () (h)
-
Move backward one character, without changing lines.
- backward-word (ESC-B ESC-b) (unbound)
-
Move to the beginning of the previous word.
- emacs-backward-word
-
Move to the beginning of the previous word.
- vi-backward-word (unbound) (b)
-
Move to the beginning of the previous word, vi-style.
- beginning-of-line (^A) (0)
-
Move to the beginning of the line. If already at the beginning
of the line, move to the beginning of the previous line, if any.
- vi-beginning-of-line
-
Move to the beginning of the line, without changing lines.
- end-of-line (^E)
-
Move to the end of the line. If already at the end
of the line, move to the end of the next line, if any.
- vi-end-of-line (unbound) ($)
-
Move to the end of the line.
- vi-forward-blank-word (unbound) (W)
-
Move forward one word, where a word is defined as a series of
non-blank characters.
- vi-forward-blank-word-end (unbound) (E)
-
Move to the end of the current word,
or, if at the end of the current word,
to the end of the next word,
where a word is defined as a series of
non-blank characters.
- forward-char (^F ESC-[C)
-
Move forward one character.
- vi-forward-char (unbound) (space l)
-
Move forward one character.
- vi-find-next-char (^X^F) (f)
-
Read a character from the keyboard, and move to
the next occurrence of it in the line.
- vi-find-next-char-skip (unbound) (t)
-
Read a character from the keyboard, and move to
the position just before the next occurrence of it in the line.
- vi-find-prev-char (unbound) (F)
-
Read a character from the keyboard, and move to
the previous occurrence of it in the line.
- vi-find-prev-char-skip (unbound) (T)
-
Read a character from the keyboard, and move to
the position just after the previous occurrence of it in the line.
- vi-first-non-blank (unbound) (^)
-
Move to the first non-blank character in the line.
- vi-forward-word (unbound) (w)
-
Move forward one word, vi-style.
- forward-word (ESC-F ESC-f) (unbound)
-
Move to the beginning of the next word.
The editor's idea of a word is specified with the WORDCHARS
parameter.
- emacs-forward-word
-
Move to the end of the next word.
- vi-forward-word-end (unbound) (e)
-
Move to the end of the next word.
- vi-goto-column (ESC-|) (|)
-
Move to the column specified by the numeric argument.
- vi-goto-mark (unbound) (`)
-
Move to the specified mark.
- vi-goto-mark-line (unbound) (')
-
Move to beginning of the line containing the specified mark.
- vi-repeat-find (unbound) (;)
-
Repeat the last vi-find command.
- vi-rev-repeat-find (unbound) (,)
-
Repeat the last vi-find command in the opposite direction.
History
- beginning-of-buffer-or-history (ESC-<)
-
Move to the beginning of the buffer, or if already there,
move to the first event in the history list.
- beginning-of-line-hist
-
Move to the beginning of the line. If already at the
beginning of the buffer, move to the previous history line.
- beginning-of-history
-
Move to the first event in the history list.
- down-line-or-history (^N ESC-[B) (+ j)
-
Move down a line in the buffer, or if already at the bottom line,
move to the next event in the history list.
- down-line-or-search
-
Move down a line in the buffer, or if already at the bottom line,
search forward in the history for a line beginning with the first
word in the buffer.
- down-history (unbound) (^N)
-
Move to the next event in the history list.
- history-beginning-search-backward (unbound)
-
Search backward in the history for a line beginning with the current
line up to the cursor.
This leaves the cursor in its original position.
- end-of-buffer-or-history (ESC->)
-
Move to the end of the buffer, or if already there,
move to the last event in the history list.
- end-of-line-hist
-
Move to the end of the line. If already at the end of
the buffer, move to the next history line.
- end-of-history
-
Move to the last event in the history list.
- vi-fetch-history (unbound) (G)
-
Fetch the history line specified by the numeric argument.
- history-incremental-search-backward (^R ^Xr)
-
Search backward incrementally for a specified string.
The string may begin with `^' to anchor the search to the
beginning of the line. A restricted set of editing functions is available in
the mini-buffer. An interrupt signal, as defined by the stty setting, will
stop the search and go back to the original line. An undefined key will have
the same effect. The supported functions are: backward-delete-char,
quoted-insert, accept-and-hold, accept-and-infer-next-history, accept-line and
accept-line-and-down-history; magic-space just inserts a space. Any string
that is bound to an out-string (via bindkey -s) will behave as if out-string
were typed directly.
Typing the binding of history-incremental-search-backward will get the
next occurrence of the contents of the mini-buffer. Typing the binding of
history-incremental-search-forward inverts the sense of the search. The
direction of the search is indicated in the mini-buffer. Any multi-character
string
that is not bound to one of the above functions will beep and interrupt the
search, leaving the last found line in the buffer. Any single character that
is not bound to one of the above functions, or self-insert or
self-insert-unmeta, will have the same effect but the function will be
executed.
- history-incremental-search-forward (^Xs)
-
Search forward incrementally for a specified string.
The string may begin with `^' to anchor the search to the
beginning of the line. The functions available in the mini-buffer are the same
as for history-incremental-search-backward.
- history-search-backward (ESC-P ESC-p) (K)
-
Search backward in the history for a line beginning with the first
word in the buffer.
- vi-history-search-backward (unbound) (/)
-
Search backward in the history for a specified string.
The string may begin with `^' to anchor the search to the
beginning of the line. A restricted set of editing functions is available in
the mini-buffer. An interrupt signal, as defined by the stty setting, will
stop the search, as will a character bound to vi-cmd-mode. The functions
available in the mini-buffer are: accept-line, backward-delete-char,
vi-backward-delete-char and quoted-insert. Any string
that is bound to an out-string (via bindkey -s) will behave as if out-string
were typed directly. Any other character that is not bound to self-insert or
self-insert-unmeta will beep and be ignored. If the function is called from vi
command mode, the bindings of vi insert mode will be used.
- history-search-forward (ESC-N ESC-n) (J)
-
Search forward in the history for a line beginning with the first
word in the buffer.
- vi-history-search-forward (unbound) (?)
-
Search forward in the history for a specified string.
The string may begin with `^' to anchor the search to the
beginning of the line. The functions available in the mini-buffer are the same
as for vi-history-search-backward.
- infer-next-history (^X^N)
-
Search in the history list for a line matching the current one and
fetch the event following it.
- insert-last-word (ESC-_ ESC-.)
-
Insert the last word from the previous history event at the
cursor position.
- vi-repeat-search (unbound) (n)
-
Repeat the last vi history search.
- vi-rev-repeat-search (unbound) (N)
-
Repeat the last vi history search, but in reverse.
- toggle-literal-history (ESC-R ESC-r)
-
Toggle between literal and lexical history. The default is
lexical history unless the HISTLIT option is set.
- up-line-or-history (^P ESC-[A) (- k)
-
Move up a line in the buffer, or if already at the top line,
move to the previous event in the history list.
- up-line-or-search
-
Move up a line in the buffer, or if already at the top line,
search backward in the history for a line beginning with the
first word in the buffer.
- up-history (unbound) (^P)
-
Move to the previous event in the history list.
- history-beginning-search-forward (unbound)
-
Search forward in the history for a line beginning with the current
line up to the cursor.
This leaves the cursor in its original position.
Modifying Text
- vi-add-eol (unbound) (A)
-
Move to the end of the line and enter insert mode.
- vi-add-next (unbound) (a)
-
Move forward one character and enter insert mode.
- backward-delete-char (^H ^?) (^?)
-
Delete the character behind the cursor.
- vi-backward-delete-char (unbound) (X)
-
Delete the character behind the cursor, without changing lines.
- backward-delete-word
-
Delete the word behind the cursor.
- backward-kill-line
-
Kill from the beginning of the line to the cursor position.
- backward-kill-word (^W ESC-^H ESC-^?)
-
Kill the word behind the cursor.
- vi-backward-kill-word (unbound) (^W)
-
Kill the word behind the cursor.
- capitalize-word (ESC-C ESC-c)
-
Capitalize the current word and move past it.
- vi-change (unbound) (c)
-
Read a movement command from the keyboard, and kill
from the cursor position to the endpoint of the movement.
Then enter insert mode.
If the command is vi-change, kill the current line.
- vi-change-eol (unbound) (C)
-
Kill to the end of the line and enter insert mode.
- vi-change-whole-line (unbound) (S s)
-
Kill the current line and enter insert mode.
- copy-region-as-kill (ESC-W ESC-w)
-
Copy the area from the cursor to the mark to the kill buffer.
- copy-prev-word (ESC-^_)
-
Duplicate the word behind the cursor.
- vi-delete (unbound) (d)
-
Read a movement command from the keyboard, and kill
from the cursor position to the endpoint of the movement.
If the command is vi-delete, kill the current line.
- delete-char (unbound) (x)
-
Delete the character under the cursor.
- vi-delete-char (unbound) (x)
-
Delete the character under the cursor.
- delete-word (ESC-D ESC-d)
-
Delete the current word.
- down-case-word (ESC-L ESC-l)
-
Convert the current word to all lowercase and move past it.
- kill-word
-
Kill the current word.
- gosmacs-transpose-chars
-
Exchange the two characters behind the cursor.
- vi-indent (unbound) (>)
-
Indent a number of lines.
- vi-insert (unbound) (i)
-
Enter insert mode.
- vi-insert-bol (unbound) (I)
-
Move to the beginning of the line and enter insert mode.
- vi-join (^X^J)
-
Join the current line with the next one.
- kill-line (^K) (D)
-
Kill from the cursor to the end of the line.
- vi-kill-line
-
Kill from the cursor to the beginning of the line.
- kill-region
-
Kill from the cursor to the mark.
- kill-buffer (^X^K) (^U)
-
Kill the entire buffer.
- kill-whole-line (^U) (unbound)
-
Kill the current line.
- vi-match-bracket (^X^B) (%)
-
Move to the bracket character (one of {}, (), or []) that
matches the one under the cursor.
- vi-open-line-above (unbound) (O)
-
Open a line above the cursor and enter insert mode.
- vi-open-line-below (unbound) (o)
-
Open a line below the cursor and enter insert mode.
- vi-oper-swap-case
-
Read a movement command from the keyboard, and swap
the case of all characters
from the cursor position to the endpoint of the movement.
If the movement command is vi-oper-swap-case,
swap the case of all characters on the current line.
- overwrite-mode (^X^O)
-
Toggle between overwrite mode and insert mode.
- vi-put-after (unbound) (p)
-
Insert the contents of the kill buffer after the cursor.
- quoted-insert (^V)
-
Insert the next character typed into the buffer literally.
- quote-line (ESC-')
-
Quote the current line; that is, put a ' character at the
beginning and the end, and convert all ' characters
to '\''.
- quote-region (ESC-")
-
Quote the region from the cursor to the mark.
- vi-replace (unbound) (R)
-
Enter overwrite mode.
- vi-repeat-change (unbound) (.)
-
Repeat the last vi mode text modification.
- vi-replace-chars (unbound) (r)
-
Replace the character under the cursor with a character
read from the keyboard.
- self-insert (printable characters)
-
Put a character in the buffer at the cursor position.
- self-insert-unmeta (ESC-^I ESC-^J ESC-^M)
-
Put a character in the buffer after stripping the meta bit
and converting ^M to ^J.
- vi-substitute (unbound) (s)
-
Substitute the next character(s).
- vi-swap-case (unbound) (~)
-
Swap the case of the character under the cursor and move past it.
- transpose-chars (^T)
-
Exchange the two characters to the left of the
cursor if at end of line, else exchange the
character under the cursor with the character
to the left.
- transpose-words (ESC-T ESC-t)
-
Exchange the current word with the one before it.
- vi-unindent (unbound) (<)
-
Unindent a number of lines.
- up-case-word (ESC-U ESC-u)
-
Convert the current word to all caps and move past it.
- yank (^Y) (P)
-
Insert the contents of the kill buffer at the cursor position.
- yank-pop (ESC-y) (unbound)
-
Remove the text just yanked, rotate the kill-ring,
and yank the new top. Only works following
yank or yank-pop.
- vi-yank (unbound) (y)
-
Read a movement command from the keyboard, and copy the region
from the cursor position to the endpoint of the movement
into the kill buffer.
If the command is vi-yank, copy the current line.
- vi-yank-eol (unbound) (Y)
-
Copy the region from the cursor position to the end of the line
into the kill buffer.
Arguments
- digit-argument (ESC-0..ESC-9) (0-9)
-
Start a new numeric argument, or add to the current one.
- neg-argument (ESC-- unbound)
-
Changes the sign of the following argument.
- universal-argument
-
Multiply the argument of the next command by 4.
Completion
- accept-and-menu-complete
-
In a menu completion, insert the current completion into the buffer,
and advance to the next possible completion.
- complete-word (unbound) (\)
-
Attempt completion on the current word.
- delete-char-or-list (^D)
-
Delete the character under the cursor. If the cursor
is at the end of the line, list possible completions for the
current word.
- execute-named-cmd (ESC-x) Read the name of a editor command and
-
execute it. A restricted set of editing functions is available in the
mini-buffer. An interrupt signal, as defined by the stty setting, will
abort the function. The allowed functions are: backward-delete-char,
vi-backward-delete-char, kill-region (kills the last word),
backward-kill-word, vi-backward-kill-word, kill-whole-line,
vi-kill-line, backward-kill-line, list-choices, delete-char-or-list
and accept-line. The space and tab characters, if not bound to one of
these functions, will complete the name and then list the
possibilities if the autolist option is set.
- execute-last-named-cmd (ESC-z)
-
Redo the last function executed with execute-named-cmd.
- expand-cmd-path
-
Expand the current command to its full pathname.
- expand-or-complete (TAB) (TAB ^X)
-
Attempt shell expansion on the current word.
If that fails,
attempt completion.
- expand-or-complete-prefix (unbound)
-
Attempt shell expansion on the current word upto cursor.
- expand-history (ESC-space ESC-!)
-
Perform history expansion on the edit buffer.
- expand-word (^X*)
-
Attempt shell expansion on the current word.
- list-choices (ESC-^D) (^D =)
-
List possible completions for the current word.
- list-expand (^Xg ^XG) (^G)
-
List the expansion of the current word.
- magic-space
-
Perform history expansion and insert a space into the
buffer. This is intended to be bound to space.
- menu-complete
-
Like complete-word, except that menu completion is used.
See the MENU_COMPLETE option below.
- menu-expand-or-complete
-
Like expand-or-complete, except that menu completion is used.
- reverse-menu-complete
-
See the MENU_COMPLETE option below.
Miscellaneous
- accept-and-hold (ESC-A ESC-a)
-
Push the contents of the buffer on the buffer stack
and execute it.
- accept-and-infer-next-history
-
Execute the contents of the buffer.
Then search the history list for a line matching the current one
and push the event following onto the buffer stack.
- accept-line (^J ^M)
-
Execute the contents of the buffer.
- accept-line-and-down-history (^O)
-
Execute the current line, and push the next history
event on the the buffer stack.
- vi-cmd-mode (^X^V) (^[)
-
Enter command mode; that is, use the alternate keymap.
Yes, this is bound by default in emacs mode.
- vi-caps-lock-panic (unbound) (H K)
-
Hang until any lowercase key is pressed.
This is for vi users without the mental capacity to keep
track of their caps lock key (like the author).
- clear-screen (^L ESC-^L)
-
Clear the screen and redraw the prompt.
- exchange-point-and-mark (^X^X)
-
Exchange the cursor position with the position of the mark.
- get-line (ESC-G ESC-g)
-
Pop the top line off the buffer stack and insert it at the
cursor position.
- pound-insert (unbound) (#)
-
If there is no # character at the beginning of the current line,
add one. If there is one, remove it. In either case, accept the
current line. The INTERACTIVE_COMMENTS option must be set
for this to have any usefulness.
- push-input
-
Push the entire current multiline construct onto the buffer stack and
return to the top-level (PS1) prompt.
If the current parser construct is only a single line, this is exactly
like push-line.
Next time the editor starts up or is popped with get-line, the
construct will be popped off the top of the buffer stack and loaded
into the editing buffer.
- push-line (^Q ESC-Q ESC-q)
-
Push the current buffer onto the buffer stack and clear
the buffer.
Next time the editor starts up, the buffer will be popped
off the top of the buffer stack and loaded into the editing
buffer.
- push-line-or-edit
-
At the top-level (PS1) prompt, equivalent to push-line.
At a secondary (PS2) prompt, move the entire current multiline
construct into the editor buffer.
The latter is equivalent to push-input followed by get-line.
- redisplay (unbound) (^R)
-
Redisplays the edit buffer.
- send-break (^G)
-
Abort the current editor function, eg. execute-named-command, or the
editor itself, eg. if you are in vared. Otherwise abort the parsing of
the current line.
- run-help (ESC-H ESC-h)
-
Push the buffer onto the buffer stack, and execute the
command "run-help cmd", where cmd is the current
command. run-help is normally aliased to man.
- vi-set-buffer (unbound) (")
-
Specify a buffer to be used in the following command.
- vi-set-mark (unbound) (m)
-
Set the specified mark at the cursor position.
- set-mark-command (^@)
-
Set the mark at the cursor position.
- spell-word (ESC-$ ESC-S ESC-s)
-
Attempt spelling correction on the current word.
- undefined-key
-
Beep.
- undo (^_ ^Xu ^X^U) (u)
-
Incrementally undo the last text modification.
- which-command (ESC-?)
-
Push the buffer onto the buffer stack, and execute the
command "which-command cmd", where cmd is the current
command. which-command is normally aliased to whence.
PARAMETERS
A parameter has a name, a value, and a number of attributes.
A name may be any sequence of alphanumeric
characters and _'s, or the single characters
*, @, #, ?, -, $, or !.
The value may be either a scalar (a string),
an integer, or an array.
To assign a scalar or integer value to a parameter,
use the typeset builtin.
To assign an array value, use set -A name value ....
The value of a parameter may also be assigned by writing:
-
name=value ...
If the integer attribute, -i, is set for name,
the value is subject to arithmetic evaluation.
The value of an array parameter may be assigned by writing:
-
name=(value ...) ...
Individual elements of an array may be selected using a
subscript. A subscript of the form [exp]
selects the single element exp, where exp is
an arithmetic expression. The elements are numbered
beginning with 1.
A subscript of the form [*] or [@] evaluates to all
elements of an array; there is no difference between the two
except when they appear within double quotes.
"$foo[*]" evaluates to "$foo[1] $foo[2] ...", while
"$foo[@]" evaluates to "$foo[1]" "$foo[2]", etc.
A subscript of the form [exp1,exp2]
selects all elements in the range exp1 to exp2,
inclusive.
If one of the subscripts evaluates to a negative number,
say -n, then the nth element from the end
of the array is used. Thus "$foo[-3]" is the third element
from the end of the array foo, and
"$foo[1,-1]" is the same as "$foo[*]".
Subscripting may also be performed on non-array values, in which
case the subscripts specify a substring to be extracted.
For example, if FOO is set to foobar, then
echo $FOO[2,5] prints ooba.
If a subscript is used on the left side of an assignment the selected
range is replaced by the expression on the right side.
If the opening bracket or the comma is directly followed by an opening
parentheses the string up to the matching closing one is considered to
be a list of flags. The flags currently understood are:
-
- e
-
the argument is expanded using full shell expansion first
- w
-
if the parameter subscripted is a scalar than this flag makes
subscription work on a per-word basis instead of characters
- s:string:
-
this gives the string that separates words (for use with the
w flag)
- r
-
if this flag is given the exp is taken as a pattern and the
result is the first matching array element, substring or word (if the
parameter is an array, if it is a scalar, or if it is a scalar and the
w flag is given, respectively); note that this is like giving a
number: $foo[(r)??,3] and $foo[(r)??,(r)f*] work
- R
-
like r, but gives the last match
- i
-
like r, but gives the index of the match instead; this may not
be combined with a second argument
- I
-
like i, but gives the index of the last match
- n:expr:
-
if combined with r, R, , or I, makes them give
the n'th or n'th last match (if expr evaluates to
n)
Positional Parameters
Positional parameters are set by the shell on invocation,
by the set builtin, or by direct assignment.
The parameter n, where n is a number,
is the nth positional parameter.
The parameters *, @, and argv are
arrays containing all the positional parameters;
thus argv[n], etc. is equivalent to simply n.
Special Parameters
The following parameters are automatically set by the shell:
-
- !
-
The process id of the last background command invoked.
- #
-
The number of positional parameters in decimal.
- ARGC
-
Same as #.
- $
-
The process id of this shell.
- -
-
Flags supplied to the shell on invocation or by the set
or setopt commands.
- *
-
An array containing the positional parameters.
- argv
-
Same as *.
- @
-
Same as argv[@].
- ?
-
The exit value returned by the last command.
- status
-
Same as ?.
- _
-
The last argument of the previous command.
Also, this parameter is set in the environment of every command
executed to the full pathname of the command.
- EGID
-
The effective group id of the shell process.
- EUID
-
The effective user id of the shell process.
- ERRNO
-
The value of errno as set by the most recently failed system call.
This value is system dependent and is intended for debugging
purposes.
- GID
-
The group id of the shell process.
- HOST
-
The current hostname.
- HOSTTYPE
-
A string corresponding to the type of the host the shell
is running on.
- LINENO
-
The line number of the current line within the current script
being executed.
- OLDPWD
-
The previous working directory.
- OPTARG
-
The value of the last option argument processed by the getopts
command.
- OPTIND
-
The index of the last option argument processed by the getopts
command.
- PPID
-
The process id of the parent of the shell.
- PWD
-
The present working directory.
- RANDOM
-
A random integer from 0 to 32767, newly generated each time
this parameter is referenced. The random number generator
can be seeded by assigning a numeric value to RANDOM.
- SECONDS
-
The number of seconds since shell invocation. If this parameter
is assigned a value, then the value returned upon reference
will be the value that was assigned plus the number of seconds
since the assignment.
- SHLVL
-
Incremented by one each time a new shell is started.
- signals
-
An array containing the names of the signals.
- TTY
-
The name of the tty associated with the shell, if any.
- UID
-
The user id of the shell process.
- USERNAME
-
- LOGNAME
-
The username corresponding to the user id of the shell process.
- VERSION
-
The version number of this zsh.
The following parameters are used by the shell:
-
- ARGV0
-
If exported, it's value is used as argv[0] of external commands.
Usually used in constructs like 'ARGV0=emacs nethack'.
- BAUD
-
The baud rate of the current connection. Used by the line editor
update mechanism to compensate for a slow terminal by delaying
updates until necessary. This may be profitably set to a lower value
in some circumstances, e.g.
for slow modems dialing into a communications server which is connected
to a host via a fast link; in this case, this variable
would be set by default to the speed of the fast link, and not
the modem.
This parameter should be set to the baud
rate of the slowest part of the link for best performance. The compensation
mechanism can be turned off by setting the variable to zero.
- cdpath (CDPATH)
-
An array (colon-separated list)
of directories specifying the search path for the cd command.
- COLUMNS
-
The number of columns for this terminal session.
Used for printing select lists and for the line editor.
- DIRSTACKSIZE
-
The maximum size of the directory stack. If the
stack gets larger than this, it will be truncated automatically.
This is useful with the AUTO_PUSHD option.
- FCEDIT
-
The default editor for the fc builtin.
- fignore (FIGNORE)
-
An array (colon separated list)
containing the suffixes of files to be ignored
during filename completion.
- fpath (FPATH)
-
An array (colon separated list)
of directories specifying the search path for
function definitions. This path is searched when a function
with the -u attribute is referenced. If an executable
file is found, then it is read and executed in the current environment.
- HISTCHARS
-
Three characters used by the shell's history and lexical analysis
mechanism. The first character signals the start of a history
substitution (default `!'). The second character signals the
start of a quick history substitution (default `^'). The third
character is the comment character (default `#').
- HISTFILE
-
The file to save the history in when an interactive shell exits.
If unset, the history is not saved.
- HISTSIZE
-
The maximum size of the history list.
- HOME
-
The default argument for the cd command.
- IFS
-
Internal field separators, normally space, tab, and newline, that
are used to separate words which result from
command or parameter substitution and words read by
the read builtin.
- KEYTIMEOUT
-
The time the shell waits, in hundredths of seconds, for another key to
be pressed when reading bound multi-character sequences.
- LINES
-
The number of lines for this terminal session.
Used for printing select lists and for the line editor.
- LISTMAX
-
In the line editor,
the number of filenames to list without asking first.
If set to zero, the shell asks only if the top of the listing would scroll
off the screen.
- LITHISTSIZE
-
The maximum size of the literal history list (before history expansion).
- LOGCHECK
-
The interval in seconds between checks for login/logout activity
using the watch parameter.
- MAIL
-
If this parameter is set and mailpath is not set,
the shell looks for mail in the specified file.
- MAILCHECK
-
The interval in seconds between checks for new mail.
- mailpath (MAILPATH)
-
An array (colon-separated list)
of filenames to check for new mail. Each filename can
be followed by a ? and a message that will be printed.
The sequence $_ in the message will be replaced by the name
of the mail file.
The default message is "You have new mail." If an element is a directory
instead of a file the shell will recursively check every file in every
subdirectory of the element.
- manpath (MANPATH)
-
An array (colon-separated list)
whose value is not used by the shell. The manpath
array can be useful, however, since setting it also sets
MANPATH, and vice versa.
- NULLCMD
-
The command name to assume if a redirection is specified
with no command. Defaults to cat. For sh/ksh-like
behavior, change this to :. For csh-like
behavior, unset this parameter; the shell will print an
error message if null commands are entered.
- path (PATH)
-
An array (colon-separated list)
of directories to search for commands.
When this parameter is set, each directory is scanned
and all files found are put in a hash table.
- POSTEDIT
-
This string is output whenever the line editor exits.
It usually contains termcap strings to reset the terminal.
- PROMPT
-
The primary prompt string, printed before a command is read;
the default is "%m%# ". If the escape sequence takes an optional
integer, it should appear between the '%' and the next character of the
sequence. The following escape sequences are recognized:
-
- %d
-
- %/
-
Present working directory ($PWD).
- %~
-
$PWD.
If it has a named directory as its prefix, that part is replaced
by a ~ followed by the name of the directory.
If it starts with $HOME, that part is
replaced by a ~.
- %c
-
- %.
-
- %C
-
Trailing component of $PWD.
An integer may follow the '%' to get more than one component.
Unless %C is used, tilde expansion is performed first.
- !
-
- %h
-
- %!
-
Current history event number
- %M
-
The full machine hostname.
- %m
-
The hostname up to the first '.'.
An integer may follow the '%' to specify
how many components of the hostname are desired.
- %S (%s)
-
Start (stop) standout mode.
- %U (%u)
-
Start (stop) underline mode.
- %B (%b)
-
Start (stop) boldface mode.
- %t
-
- %@
-
Current time of day, in 12-hour, am/pm format.
- %T
-
Current time of day, in 24-hour format.
- %*
-
Current time of day in 24-hour format, with seconds.
- %n
-
$USERNAME.
- %w
-
The date in day-dd format.
- %W
-
The date in mm/dd/yy format.
- %D
-
The date in yy-mm-dd format.
- %D{string}
-
string is formatted using the strftime function.
See strftime(3) for more details, if your system has it.
- %l
-
The line (tty) the user is logged in on.
- %?
-
The return code of the last command executed just before the prompt.
- %_
-
The status of the parser, i.e. the shell constructs (like `if' and
`for') that have been started on the command line. If given an integer
number that many strings will be printed.
- %E
-
Clears to end of line.
- %#
-
A '#' if the shell is running as root, a '%' if not.
Equivalent to %(#.#.%%).
- %v
-
The value of the first element of the $psvar array parameter. Following
the '%' with an integer gives that element of the array.
- %{...%}
-
Include a string as a literal escape sequence.
The string within the braces should not change the cursor
position.
- %(x.true-text.false-text)
-
Specifies a ternary expression. The character following the x is
arbitrary; the same character is used to separate the text for the
"true" result from that for the "false" result. Both the separator and
the right parenthesis may be escaped with a backslash. True-text
and false-text may both contain arbitrarily-nested escape
sequences, including further ternary expressions. The left
parenthesis may be preceded or followed by a positive integer n,
which defaults to zero. The test character x may be any of the
following:
-
c
- .
-
- ~
-
True if the current path, with prefix replacement, has at least n
elements.
- /
-
- C
-
True if the current absolute path has at least n elements.
- t
-
True if the time in minutes is equal to n.
- T
-
True if the time in hours is equal to n.
- d
-
True if the day of the month is equal to n.
- D
-
True if the month is equal to n (January = 0).
- w
-
True if the day of the week is equal to n (Sunday = 0).
- ?
-
True if the exit status of the last command was n.
- #
-
True if the effective uid of the current process is n.
- g
-
True if the effective gid of the current process is n.
- L
-
True if the SHLVL parameter is at least n.
- S
-
True if the SECONDS parameter is at least n.
- v
-
True if the array psvar has at least n elements.
- _
-
True if at least n shell constructs were started.
- PROMPT2
-
The secondary prompt, printed when the shell needs more information
to complete a command.
Recognizes the same escape sequences as $PROMPT.
The default is "> ".
- PROMPT3
-
Selection prompt used within a select loop.
Recognizes the same escape sequences as $PROMPT.
The default is "?# ".
- PROMPT4
-
The execution trace prompt. Default is "+ ".
- PS1
-
- PS2
-
- PS3
-
- PS4
-
Same as PROMPT, PROMPT2, PROMPT3, and PROMPT4,
respectively.
- psvar (PSVAR)
-
An array (colon-separated list) whose first nine values can be used in
PROMPT strings. Setting psvar also sets PSVAR, and
vice versa.
- prompt
-
Same as PROMPT.
- READNULLCMD
-
The command name to assume if a single input redirection
is specified with no command. Defaults to more.
- REPORTTIME
-
If nonnegative, commands whose combined user and system execution times
(measured in seconds) are greater than this value have timing
statistics printed for them.
- RPROMPT
-
- RPS1
-
This prompt is displayed on the right-hand side of the screen
when the primary prompt is being displayed on the left.
This does not work if the SINGLELINEZLE option is set.
Recognizes the same escape sequences as PROMPT.
- SAVEHIST
-
The maximum number of history events to save in the history file.
- SPROMPT
-
The prompt used for spelling correction. The sequence
%R expands to the string which presumably needs spelling
correction, and %r expands to the proposed correction.
All other PROMPT escapes are also allowed.
- STTY
-
If this parameter is set in a command's environment, the shell runs the
stty command with the value of this parameter as arguments in order to
set up the terminal before executing the command. The modes apply only to the
command, and are reset when it finishes or is suspended. If the command is
suspended and continued later with the fg or wait builtins it will
see the modes specified by STTY, as if it were not suspended. This
(intentionally) does not apply if the command is continued via "kill -CONT".
STTY is ignored if the command is run in the background, or if it is in the
environment of the shell but not explicitly assigned to in the input line. This
avoids running stty at every external command by accidentally exporting it.
Also note that STTY should not be used for window size specifications; these
will not be local to the command.
- TIMEFMT
-
The format of process time reports with the time keyword.
The default is "%E real %U user %S system %P %J".
Recognizes the following escape sequences:
-
- %U
-
CPU seconds spent in user mode.
- %S
-
CPU seconds spent in kernel mode.
- %E
-
Elapsed time in seconds.
- %P
-
The CPU percentage, computed as (%U+%S)/%E.
- %W
-
Number of times the process was swapped.
- %X
-
The average amount in (shared) text space used in Kbytes.
- %D
-
The average amount in (unshared) data/stack space used in Kbytes.
- %K
-
The total space used (%X+%D) in Kbytes.
- %M
-
The maximum memory the process had in use at any time in Kbytes.
- %F
-
The number of major page faults (page needed to be brought from disk).
- %R
-
The number of minor page faults.
- %I
-
The number of input operations.
- %O
-
The number of output operations.
- %r
-
The number of socket messages received.
- %s
-
The number of socket messages sent.
- %k
-
The number of signals received.
- %w
-
Number of voluntary context switches (waits).
- %c
-
Number of involuntary context switches.
- %J
-
The name of this job.
- TMOUT
-
If this parameter is nonzero, the shell will terminate if a command is not
entered within the specified number of seconds after issuing
a prompt.
- TMPPREFIX
-
A pathname prefix which the shell will use for all temporary files.
Note that this should include an initial part for the file name as
well as any directory names. The default is /tmp/zsh.
- watch (WATCH)
-
An array (colon-separated list) of login/logout events to report.
If it contains the single word "all", then all login/logout events
are reported. If it contains the single word "notme", then all
events are reported as with "all" except $USERNAME.
An entry in this list may consist of a username,
an `@' followed by a remote hostname,
and a `%' followed by a line (tty).
Any or all of these components may be present in an entry;
if a login/logout event matches all of them,
it is reported.
- WATCHFMT
-
The format of login/logout reports if the watch parameter is set.
Default is "%n has %a %l from %m."
Recognizes the following escape sequences:
-
- %n
-
The name of the user that logged in/out.
- %a
-
The observed action, i.e. "logged on" or "logged off".
- %l
-
The line (tty) the user is logged in on.
- %M
-
The full hostname of the remote host.
- %m
-
The hostname up to the first ".". If only the
ip address is available or the utmp field contains
the name of an X-windows display, the whole name is printed.
- NOTE:
-
The %m and %M escapes will work only if there is a host name
field in the utmp on your machine. Otherwise they are
treated as ordinary strings.
- %S (%s)
-
Start (stop) standout mode.
- %U (%u)
-
Start (stop) underline mode.
- %B (%b)
-
Start (stop) boldface mode.
- %t
-
- %@
-
The time, in 12-hour, am/pm format.
- %T
-
The time, in 24-hour format.
- %w
-
The date in day-dd format.
- %W
-
The date in mm/dd/yy format.
- %D
-
The date in yy-mm-dd format.
- %(x:true-text:false-text)
-
Specifies a ternary expression.
The character following the x is
arbitrary; the same character is used to separate the text
for the "true" result from that for the "false" result.
Both the separator and the right parenthesis may be escaped
with a backslash.
Ternary expressions may be nested.
The test character x may be any one of l, n, m,
or M, which indicate a "true" result if the corresponding
escape sequence would return a non-empty value; or may be a,
which indicates a "true" result if the watched user has logged in,
or "false" if he has logged out.
Other characters evaluate to neither true nor false; the entire
expression is omitted in this case.
If the result is "true", then the true-text
is formatted according to the rules above and printed,
and the false-text is skipped.
If "false", the true-text is skipped and the false-text
is formatted and printed.
Either or both of the branches may be empty, but
both separators must be present in any case.
- WORDCHARS
-
A list of nonalphanumeric characters considered part of a word
by the line editor.
- ZDOTDIR
-
The directory to search for shell startup files (.zshrc, etc),
if not $HOME.
OPTIONS
The following options may be set upon invocation of the shell,
or with the set or setopt builtins. They are case insensitive and
underscores are ignored, that is, "allexport" is equivalent to "A__lleXP_ort".
-
- ALL_EXPORT (-a)
-
All parameters subsequently defined are automatically exported.
- ALWAYS_LAST_PROMPT
-
If unset, key functions that list completions try to return to the last
prompt if given a numeric argument. If set these functions try to
return to the last prompt if given no numeric argument.
- ALWAYS_TO_END
-
If a completion with the cursor in the word was started and it results
in only one match, the cursor is placed at the end of the word.
- APPEND_HISTORY
-
If this is set, zsh sessions will append their history list to
the history file, rather than overwrite it. Thus, multiple parallel
zsh sessions will all have their history lists added to the
history file, in the order they are killed.
- AUTO_CD (-J)
-
If a command is not in the hash table, and there exists an
executable directory by that name, perform the cd
command to that directory.
- AUTO_LIST (-9)
-
Automatically list choices on an ambiguous completion.
- AUTO_MENU
-
Automatically use menu completion after the second consecutive request for
completion, for example by pressing the TAB key repeatedly. This option
is overridden by MENU_COMPLETE.
- AUTO_NAME_DIRS
-
Any parameter that is set to the absolute name of a directory
immediately becomes a name for that directory in the usual form
~param. If this option is not set, the parameter must be used in that
form for it to become a name (a command-line completion is sufficient
for this).
- AUTO_PARAM_KEYS
-
If a parameter name was completed and the next character typed is one
of those that have to come directly after the name (like `}', `:',
etc.) they are placed there automatically.
- AUTO_PUSHD (-N)
-
Make cd act like pushd.
- AUTO_REMOVE_SLASH
-
When the last character resulting from a completion is a slash and the next
character typed is a word delimiter, remove the slash.
- AUTO_RESUME (-W)
-
Treat single word simple commands without redirection
as candidates for resumption of an existing job.
- BG_NICE (-6)
-
Run all background jobs at a lower priority. This option
is set by default.
- BRACE_CCL
-
Allow brace expansions of the form {a-zA-Z}, etc.
- CDABLE_VARS (-T)
-
If the argument to a cd command (or an implied cd with the
AUTO_CD option set) is not a directory, and does not begin with a
slash, try to expand the expression as if it were preceded by a ~ (see
Filename Expansion above).
- CHASE_LINKS (-w)
-
Resolve symbolic links to their true values.
- COMPLETE_ALIASES
-
If set, aliases on the command line are not internally substituted
before completion is attempted.
- COMPLETE_IN_WORD
-
If unset, the cursor is set to the end of the word if completion is
started. Otherwise it stays there and completion is done from both ends.
- CORRECT (-0)
-
Try to correct the spelling of commands.
- CORRECT_ALL (-O)
-
Try to correct the spelling of all arguments in a line.
- CSH_JUNKIE_HISTORY
-
A history reference without an event specifier will always refer to the
previous command.
- CSH_JUNKIE_LOOPS
-
Allow loop bodies to take the form
"list; end" instead of
"do list; done".
- CSH_JUNKIE_QUOTES
-
Complain if a quoted expression runs off the end of a line;
prevent quoted expressions from containing unescaped newlines.
- CSH_JUNKIE_TILDE
-
Any unquoted = and ~ resulting from parameter substitution are eligible
for file expansion.
- CSH_NULL_GLOB
-
If a pattern for filename generation has no matches,
delete the pattern from the argument list;
do not report an error unless all the patterns
in a command have no matches.
Overrides NULLGLOB.
- ERR_EXIT (-e)
-
If a command has a non-zero exit status, execute the ZERR
trap, if set, and exit. This is disabled while running initialization
scripts.
- EXTENDED_GLOB
-
Treat the #, ~ and ^ characters as part of patterns for filename
generation, etc. (An initial unquoted ~ always produces named
directory expansion as in Filename Expansion above.)
- EXTENDED_HISTORY
-
Save beginning and ending timestamps to the history file.
The format of these timestamps is
:<beginning time>:<ending time>:<command>.
- GLOB_COMPLETE
-
When the current word has a glob pattern, do not insert all the words
resulting from the expansion but cycle through them like
MENU_COMPLETE. If no matches are found, a `*' is added to the end of the
word or inserted at the cursor if COMPLETE_IN_WORD is set, and expansion
is attempted again. Using patterns works not only for files but for all
completions, such as options, user names, etc.
- GLOB_DOTS (-4)
-
Do not require a leading . in a filename to be matched explicitly.
- HASH_CMDS
-
Place the location of each command in the hash table the first
time it is executed. If this option is unset, no path hashing
will be done at all.
- HASH_DIRS
-
Whenever a command is executed, hash the directory containing it,
as well as all directories that occur earlier in the path.
Has no effect if HASH_CMDS is unset.
- HASH_LIST_ALL
-
Whenever a command completion is attempted, make sure the entire
command path is hashed first. This makes the first completion slower.
- HIST_IGNORE_DUPS (-h)
-
Do not enter command lines into the history list
if they are duplicates of the previous event.
- HIST_IGNORE_SPACE (-g)
-
Do not enter command lines into the history list
if any command on the line begins with a blank.
- HIST_LIT (-j)
-
Use literal (unparsed) versions of the history lines
in the editor.
- HIST_NO_STORE
-
Remove the history (fc -l) command from
the history when invoked.
- HIST_VERIFY
-
Whenever the user enters a line with history substitution,
don't execute the line directly; instead, perform
history substitution and reload the line into the editing buffer.
- IGNORE_BRACES (-I)
-
Do not perform brace expansion.
- IGNORE_EOF (-7)
-
Do not exit on end-of-file. Require the use
of exit or logout instead.
- INTERACTIVE (-i)
-
This is an interactive shell.
- INTERACTIVE_COMMENTS (-k)
-
Allow comments even in interactive shells.
- KSH_OPTION_PRINT
-
Alters the way options settings are printed.
- LIST_AMBIGUOUS
-
If this option is set, completions are shown only if the completions
don't have a unambiguous prefix or suffix that could be inserted in
the command line.
- LIST_TYPES (-X)
-
When listing files that are possible completions, show the
type of each file with a trailing identifying mark.
- LOGIN (-l)
-
This is a login shell.
- LONG_LIST_JOBS (-R)
-
List jobs in the long format by default.
- MAGIC_EQUAL_SUBST
-
All unquoted arguments of the from identifier=expression
have file expansion performed on expression as if it were a
parameter assignment, although the argument is not otherwise treated
specially.
- MAIL_WARNING (-U)
-
Print a warning message if a mail file has been
accessed since the shell last checked.
- MARK_DIRS (-8)
-
Append a trailing / to all directory
names resulting from filename generation (globbing).
- MENU_COMPLETE (-Y)
-
On an ambiguous completion, instead of listing possibilities or beeping,
insert the first match immediately. Then when completion is requested
again, remove the first match and insert the second match, etc.
When there are no more matches, go back to the first one again.
reverse-menu-complete may be used to loop through the list
in the other direction. This option overrides AUTO_MENU.
- MONITOR (-m)
-
Allow job control. Set by default in interactive shells.
- NO_BAD_PATTERN (-2)
-
If a pattern for filename generation is badly formed,
leave it unchanged in the argument list instead of
printing an error.
- NO_BANG_HIST (-K)
-
Do not perform textual history substitution. Do not
treat the ! character specially.
- NO_BEEP (-B)
-
Do not beep.
- NO_CLOBBER (-1)
-
Prevents > redirection from truncating existing files.
>! may be used to truncate a file instead.
Also prevents >> from creating files.
>>! may be used instead.
- NO_EQUALS
-
Don't perform = filename substitution.
- NO_EXEC (-n)
-
Read commands and check them for syntax errors, but do not execute them.
- NO_GLOB (-F)
-
Disable filename generation.
- NO_FLOW_CONTROL
-
Disable output flow control via start/stop characters (usually assigned to
^S/^Q) in the shell's editor.
- NO_HIST_BEEP
-
Don't beep when an attempt is made to access a history entry which
isn't there.
- NO_HUP
-
Don't send the HUP signal to running jobs when the
shell exits.
- NO_LIST_BEEP
-
Don't beep on an ambiguous completion.
- NO_NOMATCH (-3)
-
If a pattern for filename generation has no matches,
leave it unchanged in the argument list instead of
printing an error. This also applies to file expansion
of an initial ~ or =.
- NO_PROMPT_CR (-V)
-
Don't print a carriage return just before printing
a prompt in the line editor.
- NO_RCS (-f)
-
Source only the /etc/zshenv file.
Do not source the .zshenv, /etc/zprofile, .zprofile,
/etc/zshrc, .zshrc, /etc/zlogin, .zlogin, or .zlogout files.
- NO_SHORT_LOOPS
-
Disallow the short forms of for, select,
if, and function constructs.
- NOTIFY (-5)
-
Report the status of background jobs immediately, rather than
waiting until just before printing a prompt.
- NO_UNSET (-u)
-
Treat unset parameters as an error when substituting.
- NULL_GLOB (-G)
-
If a pattern for filename generation has no matches,
delete the pattern from the argument list instead
of reporting an error. Overrides NO_NOMATCH.
- NUMERIC_GLOB_SORT
-
If numeric filenames are matched by a filename generation pattern,
sort the filenames numerically rather than lexicographically.
- OVER_STRIKE
-
Start up the line editor in overstrike mode.
- PATH_DIRS (-Q)
-
Perform a path search even on command names with slashes in them.
Thus if "/usr/local/bin" is in the user's path, and he types
"X11/xinit", the command "/usr/local/bin/X11/xinit" will be executed
(assuming it exists).
This applies to the . builtin as well as to command execution.
Commands explicitly beginning with "./" or "../" are not subject to
path search.
- PRINT_EXIT_VALUE (-C)
-
Print the exit value of programs with non-zero exit status.
- PROMPT_SUBST
-
If set expressions like ${...}, $(...), and $[...]
in prompts will be expanded.
- PUSHD_IGNORE_DUPS
-
Don't push multiple copies of the same directory onto the directory stack.
- PUSHD_MINUS
-
See popd below.
- PUSHD_SILENT (-E)
-
Do not print the directory stack after pushd
or popd.
- PUSHD_TO_HOME (-D)
-
Have pushd with no arguments act like
pushd $HOME.
- RC_EXPAND_PARAM (-P)
-
See Parameter Expansion.
- RC_QUOTES
-
Allow the character sequence '' to signify a single quote
within singly quoted strings.
- REC_EXACT (-S)
-
In completion, recognize exact matches even
if they are ambiguous.
- RM_STAR_SILENT (-H)
-
Do not query the user before executing "rm *" or "rm path/*".
- SHIN_STDIN (-s)
-
Read commands from the standard input.
- SH_WORD_SPLIT (-y)
-
See Parameter Expansion.
- SINGLE_LINE_ZLE (-M)
-
Use single-line command line editing instead of multi-line.
- SUN_KEYBOARD_HACK (-L)
-
If a line ends with a backquote, and there are an odd number
of backquotes on the line, ignore the trailing backquote.
This is useful on some keyboards where the return key is
too small, and the backquote key lies annoyingly close to it.
- VERBOSE (-v)
-
Print shell input lines as they are read.
- XTRACE (-x)
-
Print commands and their arguments as they are executed.
- ZLE (-Z)
-
Use the zsh line editor.
SHELL BUILTIN COMMANDS
- . file [ arg ... ]
-
Read commands from file and execute them in the current shell
environment.
If file does not contain a slash, or if PATH_DIRS
is set, the shell looks in the components of path to find the
directory containing file.
Files in the current directory are not read unless "." appears
somewhere in path.
If any arguments arg are given,
they become the positional parameters; the old positional
parameters are restored when the file is done executing.
The exit status is the exit status of the last command executed.
- : [ arg ... ]
-
This command only expands parameters. A zero exit code is returned.
- alias [ -grm ] [ name[=value] ] ...
-
With no arguments, print the list of aliases in the form
name=value on the standard output.
For each name with a corresponding value, define an alias
with that value.
A trailing space in value causes the next
word to be checked for alias substitution.
If the -g flag is present, define a global alias; global aliases
are expanded even if they do not occur in command position.
For each name with no value, print the value of name,
if any.
If only the -g or the -r flags are given only global or regular
aliases are listed. If the -m flag is given the arguments are taken
as patterns (they should be quoted to preserve them from being
interpreted as glob patterns) and the aliases matching these patterns
are printed.
The exit status is nonzero if a name (with no value) is
given for which no alias has been defined.
- autoload [ name ... ]
-
For each of the names (which are names of functions),
create a function marked undefined.
The fpath variable will be searched to find the
actual function definition when the function is first referenced.
-
-
bg [ job ... ]
- job ... &
-
Put each specified job in the background,
or the current job if none is specified.
-
-
bindkey -mevd
- bindkey -r in-string ...
-
- bindkey [ -a ] in-string [ command ] ...
-
- bindkey -s [ -a ] in-string out-string ...
-
The -e and -v options put the keymaps in emacs mode or vi mode
respectively; they cannot be used simultaneously. The -d option resets
all bindings to the compiled-in settings. If not used with options -e
or -v, the maps will be left in emacs mode, or in vi mode if the
VISUAL or EDITOR variables exist and contain the string "vi".
Metafied characters are bound to self-insert by default. The -m option
loads the compiled-in bindings of these characters for the mode determined by
the preceding options, or the current mode if used alone. Any previous bindings
done by the user will be preserved. If the -r option is given, remove
any binding for each in-string. If the -s option is not
specified, bind each in-string to a specified command. If no
command is specified, print the binding of in-string if it is
bound, or return a nonzero exit code if it is not bound. If the -s
option is specified, bind each in-string to each specified
out-string. When in-string is typed, out-string will be
pushed back and treated as input to the line editor. This process is recursive
but, to avoid infinite loops, the shell will report an error if more than 20
consecutive replacements happen. If the -a option is specified, bind
the in-strings in the alternative keymap instead of the standard one.
The alternative keymap is used in vi command mode.
It's possible for an in-string to be bound to something and also be the
beginning of a longer bound string. In this case the shell
will wait a certain time to see if more characters are typed and if not it
will execute the binding. This timeout is defined by the KEYTIMEOUT
parameter; its default is 0.4 sec. No timeout is done if the prefix string is
not bound.
-
For either in-string or out-string, control characters
may be specified in the form ^X, and the backslash may
be used to introduce one of the following escape sequences:
-
- \a
-
bell character
- \n
-
linefeed (newline)
- \b
-
backspace
- \t
-
horizontal tab
- \v
-
vertical tab
- \f
-
form feed
- \r
-
carriage return
- \e, \E
-
escape
- \NNN
-
character code in octal
- \xNN
-
character code in hexadecimal
- \M-xxx
-
character or escape sequence with meta bit set. The `-' after the `M' is
optional.
- \C-X
-
control character. The `-' after the `C' is optional.
In all other cases, \ escapes the following character. Delete is
written as `^?'. Note that `\M^?' and `^\M?' are not the same.
Multi-character in-strings cannot contain the null character ("^@" or
"^ "). If they appear in a bindkey command, they will be silently translated
to "\M-^@". This restriction does not apply to out-strings,
single-character in-strings and the first character of a multi-char
in-string.
- break [ n ]
-
Exit from an enclosing for, while,
until, select, or repeat loop. If n
is specified, then break n levels instead of just one.
- builtin name [ args ] ...
-
Executes the builtin name, with the given args.
- bye
-
Same as exit.
-
-
cd [ arg ]
- cd old new
-
- cd ±n
-
Change the current directory. In the first form, change the
current directory to arg, or to the value of HOME if
arg is not specified. If arg is -, change to the
value of OLDPWD, the previous directory.
If a directory named arg is not found in the current directory
and arg does not begin with a slash,
search each component of the shell parameter cdpath.
If the option CDABLEVARS is set, and a parameter named arg
exists whose value begins with a slash, treat its value as
the directory.
-
The second form of cd substitutes the string new
for the string old in the name of the current directory,
and tries to change to this new directory.
The third form of cd is equivalent to popd.
- chdir
-
Same as cd.
-
-
compctl [ -cfqovbCDAIFpEjBaRGuderzNOZ ] [ -k name ]
[ -X explanation ] [ -K function ]
[ -P prefix ] [ -S suffix ]
[ -g globstring ] [ -s subststring ]
[ -H num pattern ] [ -l cmd ] [
arg ... ]
- compctl flags + flags + ...
-
- compctl flags -x pattern flags - ... -- arg ...
-
Control the editor's completion behavior when one of arg is the current
command. (Note that aliases are expanded before this is determined,
unless the COMPLETE_ALIASES option is set.)
With the -D flag, control default completion behavior
for commands not assigned any special behavior; with -C, control
completion when there is no current command. The remaining options
specify the type of command arguments to look for during completion.
If completion is attempted for a command with a pathname containing
slashes and no completion definition is found, the search is retried
with the last pathname component.
-
-
-
-c
Expect command names.
- -f
-
Expect filenames and filesystem paths.
- -o
-
Expect option names.
- -v
-
Expect variable names.
- -b
-
Expect key binding names.
- -A
-
Expect array names.
- -I
-
Expect integer variable names.
- -F
-
Expect function names.
- -p
-
Expect parameter names.
- -E
-
Expect environment variable names.
- -j
-
Expect job names (the first word of the job leader's command line, useful
with the kill builtin).
- -r
-
Expect names of running jobs.
- -z
-
Expect names of suspended jobs.
- -B
-
Expect names of builtin commands.
- -a
-
Expect alias names.
- -R
-
Expect names of regular aliases.
- -G
-
Expect names of global aliases.
- -u
-
Expect user names.
- -d
-
Expect names of disabled commands.
- -e
-
Expect names of executable (and enabled) commands.
- -N
-
Expect names of scalar parameters.
- -O
-
Expect names of readonly variables.
- -Z
-
Expect names of shell special parameters.
- -q
-
If given together with a suffix (see the -S flag below) it
makes this suffix be removed if the next character typed is a blank or
does not insert anything (this is the same rule as used for the
AUTO_REMOVE_SLASH option).
- -k name
-
Expect names taken from the elements of $name (which should be
an array). Alternatively, the
argument name itself may be a set of space- or comma-separated
values in parentheses, in which any delimiter may be escaped with a
backslash. (Example: `compctl -k "(cputime filesize datasize stacksize
coredumpsize resident descriptors)" limit'.)
- -K function
-
Call the given function to get the completions. The function gets two
arguments: the prefix and the suffix of the word on which completion
is tried.
The function should set the variable reply to an array
containing the completions (one completion per element); note that
reply should not be made local. From such a function the
command line can be accessed with the -c and -l flags to
the read builtin.
(Example: `function whoson { reply=(`users`); };
compctl -K whoson talk' completes only logged-on users after `talk'.) Note
that whoson must return an array so that just "reply=`users`" is incorrect.
- -X explanation
-
Print the explanation string when trying completion. A `%n' in
this string is replaced by the number of matches.
- -P prefix
-
The prefix is inserted just before the completed string; any
initial part already typed will be completed and the whole prefix
ignored for completion purposes. (Example: `compctl -j -P "%"
kill').
- -S suffix
-
After a unique completion is found the suffix is inserted after
the completed string.
- -g globstring
-
The globstring is expanded using filename globbing; it should be
quoted to protect it from immediate expansion. The resulting
filenames are taken as the possible completions. Use `*(/)' instead of
`*/' for directories. The fignore special parameter is not used.
More than one pattern may be given separated by blanks. (Note that
brace expansion is not part of globbing.)
- -s subststring
-
The substring is split into words and these words are than
expanded using all shell expansion mechanisms. The resulting words are
taken as possible completions. The fignore special parameter is
not used. Note that -g is faster for filenames.
- -H num pattern
-
The possible completions are taken from the last num history
lines. Only words matching pattern are taken. If num is
zero or negative the whole history is searched and if pattern is
the empty string (or '*', of course) all words are taken.
- -l cmd
-
This option can not be combined with any other option. If it is given
it restricts the range of command line words that are considered to be
arguments. By default this range contains all arguments without the
command string. If combined with extended completion (see below) and
one of the patterns
`p[...]', `r[...]', or `R[...]' the range is
restricted to the arguments between the ones that are specified in the
brackets. After the range of arguments is determined completion is
done in it as if they were arguments to the cmd given with this
option. If this string is empty the first word in the range is taken
as the command name for which to complete. In this case, if the cursor
is in the first word, command names are completed.
Example: `compctl -x 'r[-exec,;]' -l '' -- find' completes the
arguments between `-exec' and the following `;' (or the end of the
command line if there is no such string) as if they were specifying a
command on there own.
- -U
-
Use the whole list of possible completions, whether or not they actually
match the word on the command line. The word typed so far will be
deleted. This is most useful with a function (-K option), which
can examine the word via the read builtin's -c and
-l flags and use its own criterion to decide what matches.
The second form specifies alternative options. First completion is
tried with the options before the first `+'. If this produces no
matches completion is tried with the flags after the `+' and so on. If
there are no flags after the last `+' this means that default
completion is tried if no matches were found.
The third form specifies extended completion for the commands given as
arg. Each pattern is examined in turn; when a match is found,
the corresponding flags, as described above for the ordinary case,
are used to generate possible completions. If no pattern matches,
the flags given before the -x are used. Note that each
pattern should be supplied as a single argument and should be
quoted to prevent expansion of metacharacters by the shell. A pattern
is built of sub-patterns separated by commas; it matches if at least one of
these sub-patterns matches (they are `or'ed'). These sub-patterns are in
turn composed of other sub-patterns separated by white spaces which match
if all of the sub-patterns match (they are `and'ed').
An element of the sub-patterns is of the form 'c[...][...]', where
the pairs of brackets may be repeated as often as necessary, and matches
if any of the sets of brackets match (an `or'). These elements may be
any of the following:
-
-
-
s[string] ...
The pattern matches if the current word on the command line starts with
one of the strings given in brackets. The string is not removed
and is not part of the completion.
- S[string] ...
-
Like s[string] but the string is part of the completion.
- p[from,to] ...
-
The pattern matches if the number of the current word is between one of
the from and to pairs. The comma and to are optional;
to defaults to the same value as from. The numbers may be
negative: -n refers to the n'th last word on the line.
- c[offset,string] ...
-
The pattern matches if one of the strings matches the word offset by
offset from the current word position.
- C[offset,pattern] ...
-
This is like c but uses pattern matching instead.
- w[index,string] ...
-
The pattern matches if the word in position index is equal
to the corresponding string. Note that the word count is made
after alias expansion.
- W[index,pattern] ...
-
Like w but using pattern matching instead.
- n[index,string] ...
-
Matches if the current word contains string. Anything up to and
including the
index'th occurrence of this string will not be considered part of
the completion, but the rest will.
- N[index,string] ...
-
Like n[index,string] but the string will be taken as
a character class (anything up to and including the index'th
occurrence of any
of the characters in string will not be considered part of the
completion).
- m[min,max] ...
-
Matches if the total number of words lies between min and
max (inclusive).
- r[str1,str2]...
-
Matches if the cursor is after a word with prefix str1. If there
is also a word with prefix str2 on the command line it matches
only if the cursor is before this word.
- R[str1,str2]...
-
Like r but using pattern matching instead.
Example:
-
compctl -u -x 's[+] c[-1,-f],s[-f+]' -g '~/Mail/*(:t)' \
- 's[-f],c[-1,-f]' -f -- mail
Complete users by default. After a -f with an optional space, complete
file names; if a + follows the -f, whether or not there is a space in
between, complete with the non-directory part of files in the directory
~/Mail.
- continue [ num ]
-
Resume the next iteration of the enclosing
for, while, until, select, or
repeat loop. If n is specified, break out of
n - 1 loops and resume at the nth enclosing loop.
- declare [ arg ... ]
-
Same as typeset.
- dirs [ -v ] [ arg ... ]
-
With no arguments, print the contents of the directory stack.
If the -v option is given, number the directories
in the stack when printing.
Directories are added to this stack with the pushd command,
and removed with the cd or popd commands.
If arguments are specified, load them onto the directory stack,
replacing anything that was there, and push the current directory
onto the stack.
- disable [ -m ] arg ...
-
Disable the builtin arg temporarily. This allows you to use
an external command with the same name as a shell builtin.
Without arguments all disabled builtins are printed, with the
-m flag the arguments are taken as patterns (should be quoted
to preserve them from being taken as glob patterns) and all builtins
matching these patterns are disabled.
Actually the same as unhash.
Builtins can be enabled with the enable command.
- disown job ...
-
Remove the specified jobs from the job table; the shell will
no longer report their status, and will not complain if you
try to exit an interactive shell with them running or stopped.
- echo [ -n ] [ arg ... ]
-
Write each arg on the standard output, with a space separating
each one.
If the -n flag is not present, print a newline at the end.
echo recognizes the following escape sequences:
-
- \a
-
bell character
- \b
-
backspace
- \c
-
don't print an ending newline
- \e
-
escape
- \f
-
form feed
- \n
-
newline
- \r
-
carriage return
- \t
-
horizontal tab
- \v
-
vertical tab
- \\
-
backslash
- \0NNN
-
character code in octal, with a maximum of three digits after the
zero; a non-octal digit terminates the number
- \xNN
-
character code in hexadecimal, with a maximum of two digits after the
`x'; a non-hexadecimal digit terminates the number.
- echotc cap [ arg ... ]
-
Output the termcap string corresponding to the capability
cap, with optional arguments.
- enable [ -m ] arg ...
-
Enable the specified builtin commands, presumably disabled earlier
with disable.
Without arguments the enabled builtins are printed and with the
-m flag the arguments are taken as patterns (should be quoted)
and all builtins matching these patterns are enabled.
- eval [ arg ... ]
-
Read the arguments as input to the shell and execute the resulting
command(s) in the current shell process.
- exit [ n ]
-
Exit the shell with the exit code specified by n; if none
is specified, use the exit code from the last command executed.
An EOF condition will also cause the shell to exit, unless
the IGNOREEOF option is set.
- export [ name[=value] ... ]
-
The specified names are marked for automatic export
to the environment of subsequently executed commands.
- false
-
Do nothing and return an exit code of 1.
-
-
fc [ -e ename ] [ -nlrdDfEm ] [ old=new ... ] [ first [ last ] ]
- fc -ARWI [ filename ]
-
Select a range of commands from first to last from the
history list.
The arguments first and last may be specified as a
number or as a string. A negative number is used as an offset
to the current history event number.
A string specifies the most recent event
beginning with the given string.
All substitutions old=new, if any, are then performed
on the commands.
If the -l flag is given, the resulting commands are listed on
standard output.
If the -m flag is also given the first argument is taken as a
pattern (should be quoted) and only the history events matching this
pattern will be shown.
Otherwise the editor program ename is invoked on a file containing
these history events. If ename is not given, the value
of the parameter FCEDIT is used. If ename is "-",
no editor is invoked. When editing is complete, the edited
command(s) is executed.
If first is not specified, it will be set to -1 (the most recent
event), or to -16 if the -l flag is given.
If last is not specified, it will be set to first,
or to -1 if the -l flag is given.
The flag -r reverses the order of the commands and the
flag -n suppresses command numbers when listing.
Also when listing, -d prints timestamps for each command, and
-f prints full time-date stamps. Adding the -E flag
causes the dates to be printed as `dd.mm.yyyy'.
With the -D flag, fc prints elapsed times.
-
fc -R reads the history from the given file,
fc -W writes the history out to the given file,
and fc -A appends the history out to the given file.
fc -AI (-WI) appends (writes) only those
events that are new since last incremental append (write) to
the history file. In any case the file will have no more than SAVEHIST
entries.
-
-
fg [ job ... ]
- job ...
-
Bring the specified jobs to the foreground.
If no job is specified, use the current job.
- functions [ ±tum ] [ name ... ]
-
Equivalent to typeset -f.
- getln name ...
-
Read the top value from the buffer stack and put it in
the shell parameter name. Equivalent to
read -zr. The flags -c, -l, -A,
-e, -E, and -n are supported, too.
- getopts optstring name [ arg ... ]
-
Checks arg for legal options. If arg is omitted,
use the positional parameters. A valid option argument
begins with a + or a -. An argument not beginning with
a + or a -, or the argument --, ends the options.
optstring contains the letters that getopts
recognizes. If a letter is followed by a `:', that option
is expected to have an argument. The options can be
separated from the argument by blanks.
-
Each time it is invoked, getopts places the option letter it finds
in the shell parameter name, prepended with a + when
arg begins with a +. The index of the next arg
is stored in OPTIND. The option argument, if any,
is stored in OPTARG.
A leading : in optstring causes getopts to store the
letter of the invalid option in OPTARG, and to set name
to `?' for an unknown option and to `:' when a required option
is missing. Otherwise, getopts prints an error
message. The exit status is nonzero when there are no more options.
- hash name path
-
Puts name in the command hash table, associating it with
the pathname path. Whenever name is used as a command
argument, the shell will try to execute the file given by path.
- history [ -nrdDfEm ] [ first [ last ] ]
-
Same as fc -l.
- integer [ ±lrtux ] [ name[=value] ] ...
-
Same as typeset -i, except that options irrelevant to
integers are not permitted.
- jobs [ -lprs ] [ job ... ]
-
Lists information about each given job, or all jobs
if job is omitted. The -l flag lists process
ids, and the -p flag lists process groups.
If the -r flag is specified only running jobs will be listed
and if the -s flag is given only stopped jobs are shown.
-
-
kill [ -sig ] job ...
- kill -l
-
Sends either SIGTERM or the specified signal to the given
jobs or processes.
Signals are given by number or by names
(with the prefix "SIG" removed).
If the signal being sent is not KILL or CONT, then the job
will be sent a CONT signal if it is stopped.
The argument job can be the process id of a job
not in the job list.
In the second form, kill -l, the signal names
are listed.
- let arg ...
-
Evaluate each arg as an arithmetic expression.
See ARITHMETIC EVALUATION above for a description
of arithmetic expressions. The exit status is 0 if the
value of the last expression is nonzero, and 1 otherwise.
-
-
limit [ -h ] [ resource [ limit ] ] ...
- limit -s
-
Limit the resource consumption of the current shell and its children.
If limit is not specified, print the current limit placed
on resource; otherwise
set the limit to the specified value. If the -h flag
is given, use hard limits instead of soft limits.
If no resource is given, print all limits.
-
resource is one of:
- cputime
-
Maximum CPU seconds per process.
- filesize
-
Largest single file allowed.
- datasize
-
Maximum data size (including stack) for each process.
- stacksize
-
Maximum stack size for each process.
- coredumpsize
-
Maximum size of a core dump.
- resident
-
Maximum resident set size.
- memoryuse
-
The same as resident.
- memorylocked
-
Maximum amount of memory locked in RAM.
- descriptors
-
Maximum value for a file descriptor.
- openfiles
-
Maximum number of open files.
- vmemorysize
-
Maximum amount of virtual memory.
Which of these resource limits are available depends on the system.
limit is a number, with an optional scaling factor, as follows:
- nh
-
hours.
- nk
-
kilobytes.
This is the default for all but cputime.
- nm
-
megabytes or minutes.
- mm:ss
-
minutes and seconds.
- local [ ±LRZilrtu [n]] [ name[=value] ] ...
-
Same as typeset, except that the options -x and
-f are not permitted.
- log
-
List all users currently logged in who are affected by
the current setting of the watch parameter.
- logout
-
Exit the shell, if this is a login shell.
- popd [ ±n ]
-
Removes entries from the directory stack. With no arguments,
removes the top directory from the stack, and performs a cd
to the new top directory. With an argument of the form +n,
remove the nth entry counting from the left of the list
shown by the dirs command, starting with zero, and change
to that directory. With an argument of the form -n,
remove the nth entry counting from the right.
If the PUSHD_MINUS option is set, the meanings of +
and - in this context are swapped.
- print [ -RnrslzpNDPoOic ] [ -un ] [ arg ... ]
-
With no flags or with flag -, the arguments are printed on
the standard output as described by echo, with the following differences:
the escape sequence \M-x metafies the character x (sets the highest
bit), \C-x produces a control character (\C-@ and \C-? give the
characters NULL and delete) and \E is a synonym for \e.
Finally, if not in an escape
sequence, \ escapes the following character and is not printed.
-
- -R, -r
-
ignore the escape conventions of echo.
The -R option will print all subsequent
arguments and options.
- -s
-
place the results in the history list instead of on the standard output.
- -n
-
do not add a newline to the output.
- -l
-
print the arguments separated by newlines instead of spaces.
- -N
-
print the arguments separated and terminated by nulls.
- -o
-
print the arguments sorted in ascending order.
- -O
-
print the arguments sorted in descending order.
- -i
-
if given together with -o or -O makes them work case
independently
- -c
-
print the arguments in columns
- -un
-
print the arguments to file descriptor n.
- -p
-
print the arguments to the input of the coprocess.
- -z
-
push the arguments onto the editing buffer stack, separated by spaces;
no escape sequences are recognized.
- -D
-
treat the arguments as directory names, replacing prefixes with ~
expressions, as appropriate.
- -P
-
recognize the same escape sequences as in the PROMPT parameter.
-
-
pushd [ arg ]
- pushd old new
-
- pushd ±n
-
Change the current directory, and push the old current directory
onto the directory stack. In the first form, change the
current directory to arg.
If arg is not specified, change to the second directory
on the stack (that is, exchange the top two entries), or
change to the value of HOME if the PUSHD_TO_HOME
option is set or if there is only one entry on the stack.
If arg is -, change to the
value of OLDPWD, the previous directory.
If a directory named arg is not found in the current directory
and arg does not contain a slash,
search each component of the shell parameter cdpath.
If the option CDABLEVARS is set, and a parameter named arg
exists whose value begins with a slash, treat its value as
the directory.
If the option PUSHD_SILENT is not set, the directory
stack will be printed after a pushd is performed.
-
The second form of pushd substitutes the string new
for the string old in the name of the current directory,
and tries to change to this new directory.
The third form of pushd is equivalent to popd.
- pushln
-
Equivalent to print -nZ.
- pwd
-
Equivalent to print -R $PWD.
- r
-
Equivalent to fc -e -.
- read [ -rzpqAclneE ] [ -k [ num ] ] [ -un ] [ name?prompt ] [ name ... ]
-
Read one line and break it into fields using the characters
in IFS as separators. In raw mode, -r, a \
at the end of a line does not signify line continuation.
With the -q flag read only one character and set name to
`y' if this character was `y' or `Y' and to `n' otherwise.
If the -k flag is given read only one (or num) characters.
If the -z flag is set, read from the editor buffer stack.
The first field is assigned to the first name, the second field
to the second name, etc., with leftover
fields assigned to the last name.
If the -e or the -E flag is given, the words read are
printed after the whole line is read. If the -e flag is set,
the words are not assigned to the parameters.
If the -A flag is set, the first name is taken as the
name of an array and all words are assigned to it.
The -c and -l flags are allowed only if called inside a
function used for completion (specified with the -K flag to
compctl). If the -c flag is given, the words of the
current command are read. If the -l flag is given, the whole
line is assigned as a scalar. Together with the -n flag these
options give the number of the word the cursor is on and the index of
the character the cursor is on respectively.
If name is omitted then REPLY is used for scalars and
reply for arrays.
If -un is specified, then input is read from file
descriptor n; if -p is specified, then input is
read from the coprocess.
If the first argument contains a ?, the remainder of this
word is used as a prompt on standard error when the shell
is interactive. The exit status is 0 unless an end-of-file
is encountered.
- readonly [ name[=value] ] ...
-
The given names are marked readonly; these names
cannot be changed by subsequent assignment.
- rehash [ -f ]
-
Throw out the command hash table and start over.
If the -f option is set, rescan the command path
immediately, instead of rebuilding the hash table incrementally.
- return [ n ]
-
Causes a shell function or . script to return to
the invoking script
with the return status specified by n. If n
is omitted then the return status is that of the last command
executed.
-
If return was executed from a trap, whether set by the trap
builtin or by defining a TRAPxxx function, the effect is different
for zero and non-zero return status. With zero status (or after an
implicit return at the end of the trap), the shell will return to
whatever it was previously processing; with a non-zero status, the shell
will behave as interrupted except that the return status of the trap is
retained. Note that the signal which caused the trap is passed as the
first argument, so the statement `return $[128+$1]' will return
the same status as if the signal had not been trapped.
-
-
sched [+]hh:mm command ...
- sched [ -item ]
-
Make an entry in the scheduled list of commands to execute.
The time may be specified in either absolute or relative time.
With no arguments, prints the list of scheduled commands.
With the argument -item, removes the given item
from the list.
- set [ ±options ] [ ±o option name ] ... [ -A [name] ] [ arg ] ...
-
Set the options for the shell and/or set the positional parameters, or
declare an array. For the meaning of the flags, see
OPTIONS above.
Flags may be specified by name using the -o option.
If the -A flag is specified, name is set to an
array containing the given args; if no name is specified,
all arrays are printed. Otherwise the positional parameters are set.
If no arguments are given, then the names and values
of all parameters are printed on the standard output.
If the only argument is +, the names of all parameters are printed.
- setopt [ ±options ] [ name ... ]
-
Set the options for the shell. All options specified either
with flags or by name are set. If no arguments are supplied,
the names of all options currently set are printed.
In option names, case is insignificant, and all underscore
characters are ignored.
If the -m flag is given the arguments are taken as patterns
(should be quoted to preserve them from being interpreted as glob
patterns) and all options with names matching these patterns are set.
- shift [ n ] [ name ... ]
-
The positional parameters from $n+1 ... are renamed
$1, where n is an arithmetic expression that
defaults to 1.
If any names are given then the arrays with these names are
shifted instead of the positional parameters.
- source
-
Same as ., except that the current directory is always searched and
is always searched first, before directories in path.
- suspend [ -f ]
-
Suspend the execution of the shell (send it a SIGTSTP)
until it receives a SIGCONT.
If the -f option is not given, complain if this is a login shell.
-
-
test arg ...
- [ arg ... ]
-
Like the system version of test. Added for compatibility;
use conditional expressions instead.
- times
-
Print the accumulated user and system times for the shell
and for processes run from the shell.
- trap [ arg ] [ sig ] ...
-
arg is a command to be read and executed when the shell
receives sig. Each sig can be given as a number
or as the name of a signal. Inside the command, $1 refers to the number
of the signal which caused the trap.
If arg is -, then all traps sig are reset to their
default values. If arg is the null string, then this signal
is ignored by the shell and by the commands it invokes.
If sig is ZERR then arg will be executed
after each command with a nonzero exit status.
If sig is DEBUG then arg will be executed
after each command.
If sig is 0 or EXIT
and the trap statement is executed inside the body of a function,
then the command arg is executed after the function completes.
If sig is 0 or EXIT
and the trap statement is not executed inside the body of a function,
then the command arg is executed when the shell terminates.
The trap command with no arguments prints a list of commands
associated with each signal.
- true
-
Do nothing and return an exit code of 0.
- ttyctl -fu
-
The -f option freezes the tty, and -u unfreezes it.
When the tty is frozen, no changes made to the tty settings by
external programs will be honored by the shell, except for changes in the
size of the screen; the shell will
simply reset the settings to their previous values as soon as each
command exits or is suspended. Thus, stty and similar programs have
no effect when the tty is frozen. Without options it reports whether the
terminal is frozen or not.
- type
-
Same as whence -v.
- typeset [ ±LRZfilrtuxm [n]] [ name[=value] ] ...
-
Set attributes and values for shell parameters.
When invoked inside a function a new parameter is created which will be
unset when the function completes. The new parameter will not be
exported unless ALLEXPORT is set, in which case the parameter will be
exported provided no parameter of that name already exists.
The following attributes are valid:
-
- -L
-
Left justify and remove leading blanks from value.
If n is nonzero, it defines the width of the field;
otherwise it is determined by the width of the value of the first
assignment.
When the parameter is printed, it is filled on the right with
blanks or truncated if necessary to fit the field.
Leading zeros are removed if the -Z flag is also set.
- -R
-
Right justify and fill with leading blanks. If n is nonzero
if defines the width of the field;
otherwise it is determined by the width of the value of the first
assignment.
When the parameter is printed, the field is left filled with
blanks or truncated from the end.
- -Z
-
Right justify and fill with leading zeros if the first non-blank
character is a digit and the -L flag has not been set.
If n is nonzero it defines the width of the field;
otherwise it is determined by the width of the value of the
first assignment.
- -f
-
The names refer to functions rather than parameters. No assignments
can be made, and the only other valid flags are -t
and -u. The flag -t turns on execution tracing for this
function. The flag -u causes this function to be marked
for autoloading. The fpath parameter will be searched to find the
function definition when the function is first referenced.
- -i
-
Use an internal integer representation. If n is nonzero
it defines the output arithmetic base, otherwise it is determined by the first
assignment.
- -l
-
Convert to lower case.
- -r
-
The given names are marked readonly.
- -t
-
Tags the named parameters. Tags have no special meaning to the shell.
- -u
-
Convert to upper case.
- -x
-
Mark for automatic export to the environment of subsequently
executed commands.
-
Using + rather than - causes these flags to be turned off.
If no arguments are given but flags are specified,
a list of named parameters which have these flags set is printed.
Using + instead of - keeps their values from being printed.
If no arguments or options are given, the names and attributes
of all parameters are printed. If only the -m flag is given the
arguments are taken as patterns (should be quoted) and all parameters
or functions (with the -f flag) with matching names are printed.
- ulimit [ -Hacdflmnopstv ] [ limit ]
-
Set or display a resource limit. When setting a limit it will apply to the
children of the shell but not to the shell itself. The value of limit can be a
number in the unit specified below or the value unlimited. If the
H flag is given use hard limits instead of soft limits.
-
- -a
-
Lists all of the current resource limits.
- -c
-
The number of 512-byte blocks on the size of core dumps.
- -d
-
The number of K-bytes on the size of the data segment.
- -f
-
The number of 512-byte blocks on the size of files written.
- -l
-
The number of K-bytes on the size of locked-in memory.
- -m
-
The number of K-bytes on the size of physical memory.
- -n
-
The number of file descriptors.
- -o
-
The number of open files.
- -p
-
The number of processes.
- -s
-
The number of K-bytes on the size of the stack.
- -t
-
The number of CPU seconds to be used.
- -v
-
The number of K-bytes on the size of virtual memory.
- umask [ mask ]
-
The umask is set to mask. mask can be either
an octal number or a symbolic value as described in chmod(1).
If mask is omitted, the current value is printed. Note that in
the symbolic form the permissions you specify are those which are to be
allowed (not denied) to the users specified.
- unalias [ -m ] name ...
-
The alias definition, if any, for each name is removed.
With the -m flag the arguments are taken as patterns (should be
quoted) and all aliases with matching names are removed.
- unfunction [ -m ] name ...
-
The function definition, if any, for each name is removed.
If the -m flag is specified the arguments are taken as patterns
(should be quoted) and all functions with matching names are removed.
- unhash [ -m ] name ...
-
The entry in the command hash table, if any, for each name
is removed. If the -m flag is given the arguments are taken as
patterns (should be quoted) and all entries for commands with matching
names will be removed.
- unlimit [ -h ] resource ...
-
The resource limit for each resource is set to the hard limit.
If the -h flag is given and the shell is running as root,
the hard resource limit for each resource is removed.
- unset [ -m ] name ...
-
Each named parameter is unset. If the -m flag is specified the
arguments are taken as patterns (should be quoted) and all parameters
with matching names are unset.
- unsetopt [ ±options ] [ name ... ]
-
Unset the options for the shell. All options specified either
with flags or by name are unset. If the -m flag is given the
arguments are considered to be patterns (don't forget to quote them)
and all options with names matching these patterns are unset.
- vared [ -c ] [ -p prompt ] [ -r rprompt ] name
-
The value of the parameter name is loaded into the edit
buffer, and the line editor is invoked. When the editor exits,
name is set to the string value returned by the editor.
If the -c flag is given the parameter is created if it doesn't
already exist.
If the -p flag is given the following string will be taken as
the prompt to display at the left and if the -r flag is given
the following string gives the prompt to display at the right.
- wait [ job ... ]
-
Wait for the specified jobs or processes. If job is not given
then all currently active child processes are waited for.
Each job can be either a job specification or the process-id
of a job in the job table.
The exit status from this command is that of the job waited for.
- whence [ -acpvm ] name ...
-
For each name, indicate how it would be interpreted if used
as a command name. The -v flag produces a more verbose
report. The -p flag does a path search for name
even if it is a shell function, alias, or reserved word.
The -c flag prints the results in a csh-like format.
The -a flag does a search for all occurrences of name
throughout the command path.
With the -m flag the arguments are taken as patterns (should be
quoted) and the information is displayed for each command matching one
of these patterns.
- which
-
Same as whence -c.
INVOCATION
Commands are first read from /etc/zshenv.
If the -f flag is present or if the NO_RCS option is set
within /etc/zshenv, all other
initialization files are skipped.
Otherwise, commands are read
from $ZDOTDIR/.zshenv.
(If ZDOTDIR is unset, HOME is used instead).
If the first character of argument zero passed to the shell
is -, or if the -l flag is present, then the shell is
assumed to be a login shell, and commands
are read from /etc/zprofile and then $ZDOTDIR/.zprofile.
Then, if the shell is interactive,
commands are read from /etc/zshrc and then $ZDOTDIR/.zshrc.
Finally, if the shell is a login shell, /etc/zlogin and $ZDOTDIR/.zlogin
are read.
If the -s flag is not present and an argument is given,
the first argument is taken to be the pathname of a script to
execute. The remaining arguments are assigned to the positional
parameters. The following flags are interpreted by the shell
when invoked:
-
-
-c string
Read commands from string.
- -s
-
Read command from the standard input.
- -i
-
If this flag is present or the shell input and output
are attached to a terminal, this shell is interactive.
SEE ALSO
sh(1),
csh(1),
tcsh(1),
itcsh(1),
rc(1),
bash(1),
ash(1),
ksh(1),
clam(1),
strftime(3).
FILES
$ZDOTDIR/.zshenv
$ZDOTDIR/.zprofile
$ZDOTDIR/.zshrc
$ZDOTDIR/.zlogin
$ZDOTDIR/.zlogout
/tmp/zsh*
/etc/zshenv
/etc/zprofile
/etc/zshrc
/etc/zlogin
AUTHOR
Paul Falstad (pf@z-code.com)
Programmable completion was implemented by Sven Wischnowsky
(oberon@cs.tu-berlin.de) and Peter Stephenson (pws@s-a.amtp.liv.ac.uk).
AVAILABILITY
The latest official release of zsh is available via anonymous ftp from
cs.ucsd.edu (132.239.51.3), in the directory pub/zsh. The beta release
of zsh 2.4 is available from carlo.phys.uva.nl (145.18.218.21), in the
directory pub/bas/zsh. This man page is current to zsh 2.4 patchlevel 306.
UNDOCUMENTED FEATURES
Known only to the recipients of the zsh mailing list,
zsh-list@sterling.com. If you run into problems, please send your
questions and patches to the mailing list. To subscribe to zsh-list,
send an email message with body "subscribe zsh-list" to the address
"Majordomo@sterling.com".
Index
- NAME
-
- SYNOPSIS
-
- SHELL GRAMMAR
-
- RESERVED WORDS
-
- COMMENTS
-
- ALIASING
-
- QUOTING
-
- EXPANSION
-
- Filename Expansion
-
- Process Substitution
-
- Parameter Expansion
-
- Command Substitution
-
- Arithmetic Expansion
-
- Brace Expansion
-
- Filename Generation
-
- REDIRECTION
-
- COMMAND EXECUTION
-
- FUNCTIONS
-
- JOBS
-
- SIGNALS
-
- HISTORY
-
- Event Designators
-
- Word Designators
-
- Modifiers
-
- ARITHMETIC EVALUATION
-
- CONDITIONAL EXPRESSIONS
-
- ZSH LINE EDITOR
-
- Bindings
-
- Movement
-
- History
-
- Modifying Text
-
- Arguments
-
- Completion
-
- Miscellaneous
-
- PARAMETERS
-
- Positional Parameters
-
- Special Parameters
-
- OPTIONS
-
- SHELL BUILTIN COMMANDS
-
- INVOCATION
-
- SEE ALSO
-
- FILES
-
- AUTHOR
-
- AVAILABILITY
-
- UNDOCUMENTED FEATURES
-
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Time: 01:00:28 GMT, September 26, 2024