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SHELL V2.10 (C)Copyright 1986-88, Matthew Dillon, All Rights Reserved. Freely distributable for non-profit only. PLEASE READ THE VERSION HISTORY AT THE BOTTOM FOR CHANGES FROM 2.07. Also, re-read the overview just below. (A) Compiling (B) Overview (C) Quicky tech notes on implimentation. (D) Command pre-processor (E) Command-list (F) special SET variables (G) Version history See also EXAMPLES.TXT COMPILATION The SHELL will compile only under AZTEC C and requires my support library (SUP32.LIB) to link as well as a precompiled symbol table of all AMIGA .H files. A Makefile is included. Note that the shell must be compiled using 32 bit integers (+L) option and linked with SUP32.LIB and C32.LIB. NOTE that converting the shell to use 16 bit integers does not make it significantly smaller or faster. Do not waste your time. OVERVIEW Matthew Dillon 891 Regal Rd. Berkeley, California 94708 USA ..!ucbvax!dillon dillon@ucbvax.Berkeley.EDU dillon@cory.Berkeley.EDU This is not a shareware program. My basic philosophy is to write software for myself and distribute it if I think it will benefit others (that is, unless I start going broke). Contribute if you want to. IT IS SUGGESTED THAT YOU USE CONMAN OR THE NEW 1.3 ENHANCED CONSOLE DEVICE. CONMAN does to my shell what Steve did in his Manxfied (old term) 16 bit version of my shell, and more. It isn't required, but CONMAN (shareware) complements the functionality of the shell quite well. PROBLEMS -Make sure you give the SHELL a big enough stack, especially if you intend on running shell scripts which source other scripts. 8192 is suggested. Remember, STACK must be run BEFORE you run the shell. Running it from the shell does not effect the shell's stack. -You should not redirect the RUN command. to redirect the command the RUN command is running, embed a standard CLI redirection in the command string: RUN ">file" command -Append '>>' does NOT work with BCPL programs. It does work with all internal and non-bcpl (read C) programs. OVERVIEW of the major features: -History mechanism (complements conman quite nicely, in fact) -Redirection -Piping (sort of) -Command search path by name and by CLI path list -Aliases -Variables & variable handling (embedded variables), and enviroment variables -Automatic file name expansion via '?' and '*' -Conditionals -Shell Scripts -many built in commands to speed things up COMMAND PREPROCESSOR preprocessing is done on the command line before it is passed on to an internal or external routine: ^c where c is a character is converted to that control character. Thus, say '^l' for control-l. $name where name is a variable name. Variable names can consist of 0-9, a-z, A-Z, and underscore (_). The contents of the specified variable is used. If the variable doesn't exist, the specifier is used. That is, if the variable 'i' contains 'charlie', then '$i' -> 'charlie'. If the variable 'i' doesn't exist, then '$i'->'$i' . ; delimits commands. echo charlie ; echo ben. ' ' (a space). Spaces delimit arguments. "string" a quoted string. For instance, if you want to echo five spaces and an 'a': echo a -> a echo " a" -> a \c overide the meaning of special characters. '\^a' is a circumflex and an a rather than control-a. To get a backslash, you must say '\\'. also used to overide alias searching for commands. >file specify output redirection. All output from the command is placed in the specified file. >>file specify append redirection (Does not work with BCPL programs). <file specify input redirection. The command takes input from the file rather than the keyboard (note: not all commands require input). It makes no sense to say 'echo <charlie' since the 'echo' command only outputs its arguments. | PIPE specifier. The output from the command on the left becomes the input to the command on the right. The current SHELL implimentation uses temporary files to store the data. !! execute the previously executed command. !nn (nn is a number). Insert the history command numbered n (see the HISTORY command) !partial search backwards through the history list for a command which looks the same as 'partial', and execute it. # Enter comment. The rest of the line is discarded (note: \# will, of course, overide the comment character's special meaning) ^search^replace a '^' at the beginning of the line indicates history replacement. The first occurance of 'search' in the previous command is changed to 'replace', and the command executed. SHELL COMMANDS The first argument is the command-name... if it doesn't exist in the list below and isn't an alias, it is assumed to be an external (disk) command. AUTOMATIC SOURCING may be accomplished by naming shell scripts with a .sh suffix. Thus, if you say 'stuff' and the file 'stuff.sh' exists in your current or C: directory, it will be SOURCED with any arguments you have placed in the $_passed variable. EXCEPTION_PROCESSING if no _except variable exists, any command which fails causes the rest of the line to abort as if an ABORTLINE had been executed. If the _except variable exists, it is of the form: "nnn;commands..." where nnn is some value representing the minimum return code required to cause an error. Whenever a command returns a code which is larger or equal to nnn, the commands in _except are executed before anything. WHEN _except EXISTS, THE COMMAND LINE DOES NOT ABORT AUTOMATICALLY. Thus, if you want the current line being executed to be aborted, the last command in _except should be an "abortline". exception handling is disabled while in the exception handling routine (thus you can't get into any infinite loops this way). Thus if _except = ";", return codes are completely ignored. example: set _except "20;abortline" ABORTLINE or just 'abort'. Causes the rest of the line to be aborted. Used in conjunction with exception handling. % echo a;abort;echo b a HELP simply displays all the available commands. The commands are displayed in search-order. That is, if you give a partial name the first command that matches that name in this list is the one executed. Generally, you should specify enough of a command so that it is completely unique. QUIT EXIT RETURN [n] quit my SHELL (awww!). End, El-Zappo, Kapow. Done, Finis. If you use RETURN and are on the top source level, the shell exits with the optional return code. (see RETURN below) SET SET name SET name string The first method lists all current variable settings. The second method lists the setting for that particular variable, or creates the variable if it doesn't exist (to "") The last method sets a variable to a string. see the section on special _ variables down below UNSET name name name.... unset one or more variables. Deletes them entirely. SETENV name string Create/Modify an enviroment variable. The enviroment is maintained in ENV:, with a separate file for each enviroment variable. This should be assigned to a directory somewhere. UNSETENV name name name.... remove the specified variables from the enviroment list. This call DeleteFile()'s the enviroment variable from ENV: PRINTENV Print the contents of the enviroment directory ENV: ALIAS ALIAS name ALIAS name string same as SET, but applies to the alias list. You can alias a single name to a set of commands. For instance: alias hi "echo a; echo b" then you can simply say 'hi'. Aliases come in two forms the second form allows you to place the arguments after an alias in a variable for retrieval: alias xxx "%i echo this $i is a test" % xxx charlie this charlie is a test The rest of the command line is placed in the specified variable for the duration of the alias. This is especially useful when used in conjunction with the 'FOREACH' command. UNALIAS name name name... delete aliases.. ECHO string ECHO -n string echo the string to the screen. If '-n' is specified, no newline is output. STRHEAD varname breakchar string remove everything after and including the breakchar in 'string' and place in variable 'varname': % strhead j . aaa.bbb % echo $j aaa % STRTAIL varname breakchar string remove everything before and including the breakchar in 'string' and place in variable 'varname': % strtail j . aaa.bbb % echo $j bbb % SOURCE file [arguments] execute commands from a file. You can create SHELL programs in a file and then execute them with this command. Source'd files have the added advantage that you can have loops in your command files (see GOTO and LABEL). You can pass SOURCE files arguments by specifying arguments after the file name. Arguments are passed via the _passed variable (as a single string). Automatic 'sourcing' is accomplished by placing a .sh extension on the file and executing it as you would a C program: --------- file hello.sh --------- foreach i ( $_passed ) "echo yo $i" --------------------------------- % hello a b c yo a yo b yo c NOTE: The hash '#' as the FIRST character on the line is a comment within script files. MV from to MV from from from ... from todir Allows you to rename a file or move it around within a disk. Allows you to move 1 or more files into a single directory. (if todir == '/', the items are moved to the parent directory). CD CD .. CD path Change your current working directory. You may specify '..' to go back one directory (this is a CD specific feature, and does not work with normal path specifications). Note that CD / also goes back one directory. CD without any arguments displays the path of the directory you are currently in. PWD rebuild _cwd by backtracing from your current directory. The $_cwd variable can get confused by Assign'd labels. RM [-r] file file file... DeleteFile(). Remove the specified files. Remove always returns errorcode 0. You can remove empty directories. The '-r' option will remove non-empty directories by recursively removing all sub directories. CP file (to current directory) CP [-r] dir (to current directory) CP file file CP file1 file2...fileN dir CP [-r] dir1 dir2...dirN dir copy files or directories. when copying directories, the "-r" option must be specified to copy subdirectories as well. Otherwise, only top level files in the source directory are copied. MKDIR name name name... create the following directories. HISTORY [partial_string] Displays the enumerated history list. The size of the list is controlled by the _history variable. If you specify a partial- string, only those entries matching that string are displayed. MEM Display current memory statistics for CHIP and FAST memory. CAT [file file....] Type the specified files onto the screen. If no file is specified, STDIN in used. CAT is meant to output text files only. You cannot use CAT to join binaries together. DIR [-s] [path path ... ] Get a directory listing of the current directory or specified directories. The -s option causes DIR to display a short-form listing. DEVINFO [device: device:... ] Display Device statistics for the current device (CD base), or specified devices. FOREACH varname ( strings ) command 'strings' is broken up into arguments. Each argument is placed in the variable 'varname' in turn and 'command' executed. To execute multiple commands, place them in quotes: % foreach i ( a b c d ) "echo -n $i;echo \" ha\"" a ha b ha c ha d ha Foreach is especially useful when interpreting passed arguments in an alias or source file. NOTE: a GOTO inside a FOREACH will have an indeterminate effect. FOREVER command FOREVER "command;command;command..." The specified commands are executed over and over again forever. -Execution stops if you hit ^C -If the commands return with an error code. NOTE: a GOTO inside will have an indeterminate effect. RETURN [value] return from a source file. The rest of the source file is discarded. If given, the value becomes the return value for the SOURCE command. If you are on the top level, this value is returned as the exit code for the shell. IF -f path IF argument conditional argument ; IF argument If a single argument is something to another argument. Conditional clauses allowed: <, >, =, and combinations (wire or). Thus <> is not-equal, >= larger or equal, etc... If the left argument is numeric, both arguments are treated as numeric. usually the argument is either a constant or a variable ($varname). The third form if IF is conditional on the existance of the argument. If the argument is a "" string, then FALSE , else TRUE. The first form is TRUE if the path can be openned with modes 1005. ELSE ; else clause. ENDIF ; the end of an if statement. LABEL name create a program label right here. You can only have labels within a source file. GOTO label goto the specified label name. You can only use this command from a source file. DEC var INC var decrement or increment the numerical equivalent of the variable and place the ascii-string result back into that variable. INPUT varname input from STDIN (or a redirection, or a pipe) to a variable. The next input line is placed in the variable. VER display my name, the version number, and the version date. SLEEP timeout Sleep for 'timeout' seconds. SPECIAL VARIABLES _prompt This variable is set to the command you wish executed that will create your prompt. _history This variable is set to a numerical value, and specifies how far back your history should extend. _histnum This variable contains the history # of the next command that will be executed. _debug Debug mode... use it if you dare. must be set to some value _verbose Verbose mode (for source files). display commands as they are executed. _maxerr The worst (highest) return value to date. To use this, you usually set it to '0', then do some set of commands, then check it. _lasterr Return code of last command executed. This includes internal commands as well as external comands, so to use this variables you must check it IMMEDIATELY after the command in question. _cwd Holds a string representing the current directory we are in from root. The SHELL can get confused as to its current directory if some external program changes the directory. Use PWD to rebuild the _cwd variable in these cases. _passed This variable contains the passed arguments when you SOURCE a file or execute a .sh file. For instance: test a b c d -------- file test.sh ---------- echo $_passed foreach i ( $_passed ) "echo YO $i" -------------------------------- _path This variable contains the search path when the shell is looking for external commands. The format is: DIR,DIR,DIR Each DIR must have a trailing ':' or '/'. The current directory is always searched first. The entire path will be searched first for the <command>, then for <command>.sh (automatic shell script sourcing). The default _path is set to "c:,ram:,ram:c/,df1:c/,df0:c/" NOTE: The CLI path is also searched. _ignoreeof If this variable exists, EOF is ignored on interactive terminals. This prevents accidental logouts. _copysilent If this variable exists, the CP command will be silent. The default is now for CP to be verbose. _copydate If this variables exists, the CP command will attempt to transfer the datestamp src->dst file/dir. For directories, only those that CP must create will get the old datestamp transfered to them. Additionaly, the COMMENT, if any, will the transfered src->dst file/dir. TECH NOTES PIPES have been implimented using temporary RAM: files. Thus, you should be careful when specifying a 'ram:*' expansion as it might include the temp. files. These files are deleted on completion of the pipe segment. The file names used are completely unique, even with multiple shells running simultaniously. My favorite new feature is the fact that you can now redirect to and from, and pipe internal commands. 'echo charlie >ram:x', for instance. Another favorite: echo "echo mem | shell" | shell To accomplish these new features, I completely re-wrote the command parser in execom.c The BCPL 'RUN' command should not be redirected.. .strange things happen. You can use redirection WITHIN the RUN's command line, of course, but it should be quoted so the shell doesn't think the redirection is for it. NO BCPL program should be output-append redirected (>>). VERSION HISTORY V2.10: -Command dispatch has been fixed... RUN used to create problems sometimes (would give you a CLI prompt when it should not have). -MV fixed ... had problems when moving things to the current directory ("") and names starting with '/'. -SETENV, PRINTENV commands added. $var variables search the enviroment (ENV:). Aliases are searched for in ENV: as well now. This allows you to have global variables and aliases for all the shells running in the system without having to resource an initialization file. Additionaly, to the limits of the command line, the contents of any file in ENV: may be inserted by referencing it as a variable. ANY system variable may be placed in the enviroment instead of the local variables if you wish. -DIR enhanced. Defaults to long list format. V2.08: -WaitForChar() removed from main processing loop (the old Delay(0) bug though in this case it is WaitForChar(x,1). -CP now accepts single parameters (ala MSDOS).. copy a file or directory to the current directory (-r for recursive sub-dirs) CP FILE CP [-r] DIR -A new variable, _copydate, which, if it exits, causes CP to transfer both the comment and datestamp of the source to the destination. set _copydate V2.07: (Internal) V2.06B: -External programs that change the current directory are caught, and no longer crash the machine. -CP command, the _copysilent variable, if it exists, causes directory and recursive copies to do their work in silence. V2.06: -IF enhanced. -f option added. (if -f path). If the named path can be openned with modes 1005, then... -various routines fixed. V2.04: - CP command now internal... see instructions. - RM command now has '-r' option. - \command forces the command parser NOT to look at aliases. Thus, you can alias something like 'cd' and have the alias contain a 'cd' which references the internal cd: alias cd "stuff...;\\cd $x" - "-c" command line option to execute commands and return. shell -c "echo a;echo b;echo c". - _path default now places RAM: and RAM:C first rather than last. - _histnum variable .. current history # - expanded filenames are sorted. - ^search^replace (modify previous command). V2.03 AND BELOW Before Written History (actually not quite, but there was this fire you see....)