Club Amiga de Montreal

home *** CD-ROM | disk | FTP | other *** search

/ Club Amiga de Montreal - CAM / CAM_CD_1.iso / files / 074.lha / CShell / shell.doc < prev next >

Wrap

Text File | 1986-11-20 | 25.8 KB | 917 lines

INSTRUCTIONS FOR SHELL Version: 2.07M 10-Sep-87 ================================================ Contents -------- I. Description II. Overview of Major features III. Restrictions IV. PIPES V. Command Pre-processor VI. Command Line Editing VII. Function Keys VIII. Shell Commands IX. Special Set Variables X. Advanced Topics XI. Example login file XII. Example script file I. Description ----------- Shell V2.07M is the follow on to 2.04,5,6M which originated from: Shell V2.04 by Matt Dillon: Shell V2.04 (C)Copyright 1986, Matthew Dillon, All Rights Reserved Enhanced by permission by Steve Drew. You may distribute this program for non-profit only. II. OVERVIEW -------- Shell provides a convient AmigaDos alternative command interface. All it's commands are internal and thus does not rely on the c: commands for any functionality (except the run command). Major features include: -command line editing -shell & Amigados search path support -simple history -redirection of any command -piping -aliases -variables & variable handling (embedded variables) -file name expansion via conventional wild carding ('?' and '*') -conditionals (if/else ect..) -source files (w/ gotos and labels) -many built in commands to speed things up III. RESTRICTIONS ------------ o AmigaDos execute command will not work. Alternative is to use shell own script language (which is more powerful) or to do a 'run execute'. o This version runs UNDER WORKBENCH 1.2 ONLY. o VDK handler has a bug with setting file dates so when using the copy command and VDK you should use the -d switch otherwise you file date in vdk: will be bad. (This is not a bug with shell) o If using with conman it may be best to start shell with the -a switch (shell -a .login) to turn off shell's command line editing and use conmans instead. IV. NOTES ON PIPES -------------- 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 shell 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 NO BCPL program should be output-append redirected (>>). V. COMMAND PRE-PROCESSOR --------------------- 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) VI. COMMAND LINE EDITING -------------------- o Command line can be upto 255 chars. o Inserts and deletes are handled correctly over multiple screen lines. o Shell will keep track of the line width should the window get resized. KEY DEFINITIONS: Up Arrow Recal previous commands Down Arrow Recal commands Left Arrow Move cursor about command line. Right Arrow " " " " " ^A Toggle insert/overtype mode. ^D EOF ^E Put cursor at end of text. ^K Delete to end of line. ^R Retype current line. ^U Erase entire line. ^X Erase entire line. ^Z Put cursor at start of text. f1 - f10 Execute command if variable exists. F1 - F10 More commands (Shifted f keys). Help invokes help command VII. FUNCTION KEYS ------------- Function keys now insert text to the current position on the command line. They maybe terminated with a ^M (return). f1 would be non shifted where as F1 is shifted. $ set f1 dir df0:^M will add the text 'dir df0:<return>' to the current line. $ set f1 dir would only add 'dir' you could then enter ' df0:<return>' VIII. SHELL COMMANDS --------------- First to start shell from a CLI shell [-a] [-c command;command] where: -a disables all command line editing features. This is usefull for when running shell over AUX:. -c allows execution of one command line and then exits out of shell. This is usefull for running a internal shell commands in the background or from an external application. eg: Run shell -c dir df0:; copy -r df0: df1: >nil:; echo "Done" If you 'Run' shell in the background without the -c switch shell will detect this and imediatley exit. Command execution: Internal shell commands maybe abreviated. 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. At this point the shell pathing, and AmigaDos pathing is checked in order to locate the 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. This is equivalent to typing 'source stuff.sh' Wild card expansions: Most shell commands will accept multiple arguments that can be as a result of wild card expansion. Also when the calling an external command shell will first expand any wild cards to seperate arguments. If you wish to have the external command handle it's own wild carding you will need to insert quotes arround the special wild card characters ? and *. eg. arc a new.arc *.txt - shell will expand and pass to arc arc a new.arc "*.txt" - let arc expand the wild cards. Wild card expansions: ? match any single character * match any string df0:.../* all files in all directories on df0: .../* recursive search down ALL sub directories from current level LIST OF COMMANDS: ----------------- *** NOTE: THERE EXISTS TWO VERSIONS OF SHELL 2.07M, THE ONLY DIFFERENCE IS IN ONE VERSION COMMANDS CAT, RM, MV, HAVE BEEN RENAMED TO BE TYPE, DELETE, RENAME. (I had'nt intended this version to be public for consistancy sake, but it slip out.) USE THE HELP COMMAND TO DETERMINE WHICH VERSION YOU HAVE. ABORTLINE usage : abortline example: echo a;abort;echo b results: a Causes the rest of the line to be aborted. Intended for use in conjunction with exception handling. ALIAS Usage : alias [name] [command string] example : alias vt "echo Starting VT100;run sys:tools/vt100" Sets a name to be a string. You can alias a single name to a set of commands if you enclose them in quotes as above. By simply typing vt, the command line above would be executed. Argument Passing to an Alias: Usage : alias name "%var [command string]" example : alias xx "%q echo hi $q, how are ya." xx Steve results : hi Steve, how are ya. The second form of the alias command allows passing of arguments to any position within the command string via use of a variable name. To pass arguments to the end of a command string this method is actually not necessary. CAT (TYPE) Usage : cat [file file....] example : cat foo.txt Type the specified files onto the screen. If no file is specified, STDIN in used. CAT is meant to output text files only. CD Usage : cd [path] example : cd df0:devs/printers 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). CD without any arguments displays the path of the directory you are currently in. COPY Usage : copy [-u][-d] file file or : copy [-u][-d] file1 file2...fileN dir or : copy [-r][-u][-d] dir1 dir2...dirN dir options : -r recursive, copy all subdirectories as well. -u update, if newer version exist on dest, don't copy -d don't set destination file date to that of source. example : copy -r df0: df1: 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. All files will be displayed as they are copied and directory's displayed as they are created. This output can be suppessed by redirecting to nil: eg. copy -r >nil: df0: df1: Copy will abort after current file on Control-C. Copy by default sets the date of the destination file to that of the source file. To overide this feature use the -d switch. Another useful option is the -u (update) mode were copy will not copy any files which exists already in the destination directory if the destination file is newer or equal to the source file. This is usefull when developing code say in ram: eg. 'copy *.c ram:' when done you can copy -u ram: df1: and only those modules you have modified will be copied back. Copy command will now create the destination directory if it does not exist when specified as 'copy [-r] dir dir'. If you specify copy file file file dir, then 'dir' must already exist. DEC Usage : dec varname example : dec abc Decrement the numerical equivalent of the variable and place the ascii-string result back into that variable. DEVINFO Usage : devinfo [device: device:... ] example : devinfo df0: df1: ram: Display Device statistics for the current device (CD base), or specified devices. Gives block used/free, % used, errs and volume name. DIR Usage : dir [-sdf] [path path ... ] example : dir df0: options : -s short multi(4) collum display, directories in red pen. -d list directories only -f list files only Displays a directory of specified files. Default output show's date, protection, block size, byte size. And total space used. Files are alphabetically sorted, first by upper case then by lower. (allows README files ect.. to stand out.) Wild card expansions: ? match any single character * match any string .../ recursive search down ALL sub directories dir df0:.../ does a full (All) sorted directory dir .../*.c start at current dir and go down looking for all .c files. Exclude pattern matching specifier: ! dir !*.info will exclude all *.info files in current dir. dir df0:.../!*.info full directory tree of df0: but exclude any ugly .info files. dir !*.o !*.c (will result in ALL files matching since what doesnt match the !*.o will match the !*.c) ECHO Usage : echo [-n] string example : echo hi there results : hi there Echo the string given. If -n switch given no newline is appended. ELSE ; Usage : else ; command Usage : if -f foo.c ; else ; echo "Not there" ; endif Else clause, must follow an IF statement. ENDIF Usage : endif The end of an if statement. *Note: if you return from a script file with unterminated IF's and the last IF was false. No commands will be executed until 'endif' is typed. FOREACH Usage : foreach varname ( strings ) command example : foreach i ( a b c d ) "echo -n $i;echo \" ha\"" result : a ha b ha c ha d ha '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 is especially useful when interpreting passed arguments in an alias. eg. foreach i ( *.pic ) viewilbm $i assuming a.pic and b.pic in current directory the following commands will occur: viewilbm a.pic viewilbm b.pic FOREVER Usage : forever command or : forever "command;command;command..." The specified commands are executed over and over again forever. -Execution stops if you hit ^C -If the commands return with an error code. GOTO Usage : goto label example : label start echo "At start" dir ram: goto start Goto the specified label name. You can only use this command from a source file. Labels may now be forward or reverse from current position. HELP Usage : help example : help Simply displays all the available commands. The commands are displayed in search-order. That is, if you give a partial name the first command that matches that name in this list is the one executed. Generally, you should specify enough of a command so that it is completely unique. HISTORY Usage : history [partial_string] example : history Displays the enumerated history list. The size of the list is controlled by the _history variable. If you specify a partial- string, only those entries matching that string are displayed. IF Usage : if argument conditional argument ; or : if argument or : if -f file If a single argument is something to another argument. Conditional clauses allowed: <, >, =, and combinations (wire or). Thus <> is not-equal, >= larger or equal, etc... If the left argument is numeric, both arguments are treated as numeric. usually the argument is either a constant or a variable ($varname). The second form if IF is conditional on the existance of the argument. If the argument is a "" string, then false , else TRUE. The third form of IF used by -f switch checks for existance of the specified file. When using 'IF' command interactively if you are entering commands following an 'IF' that was false, the prompt will be set to a underscore '_ ' to indicate all commands will be ignored until an 'ELSE' or 'ENDIF' command is seen. INC Usage : inc varname example : inc abc Increment the numerical equivalent of the variable and place the ascii-string result back into that variable. INPUT Usage : input var var ... var example : input abc Input from STDIN (or a redirection, or a pipe) to a variable. The next input line is placed in the variable. LABEL Usage : label name Create a program label right here. Used in source files, can then GOTO a label. MEM Usage : mem Display current memory statistics for CHIP memory and fast memory (if any installed). MKDIR Usage : mkdir name name name... example : mkdir df0:stuff Create the specified directories. MV (RENAME) Usage : mv from to or : 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. PS Usage : ps Gives status of DOS processes. eg: Proc Command Name CLI Type Pri. Address Directory 1 SHELL Initial CLI 0 97b0 Stuff:shell 2 sys:c/clockmem Background -10 2101a8 Workdisk: 3 c:emacs Background 0 212f58 Stuff:shell 4 sys:c/VT100 Background 0 227328 Workdisk: Address is the addres of the task, directory is the process currently CD'd directory. PWD Usage : pwd Rebuild _cwd by backtracing from your current directory. QUIT Usage : quit Quit out of Shell back to CLI. RETURN Usage : return [n] example : return 10 Exit from a script file, or quit from shell with optional exit code. RM (DELETE) Usage : rm [-r] file file file... example : rm foo.txt test.c Remove (delete) 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. If you specify any wildcard deletes the files will be listed as they are deleted. This can be suppressed by redirecting to nil: eg. rm df0:.../*.o delete all .o files from every directory. RUN Usage : run prgm example : run emacs Finds the specified file via $_path variable, or 2nd via AmigaDos PATH setting, then calls AmigaDos Run command with the explicit path/command. This command is really only implemented to allow consistancy in first checking the shell pathing before amigados pathing. Since shell allows for device names in _path it does'nt care when you swap disks; if you had "df0:c/" in _path then whatever disk you have in df0: will be checked. AmigaDos PATH always resolves to a Lock that points only to a particular disk label:directory. SET Usage : set [name] [string] example : set abc hello Set with no args lists all current variable settings. Set with one arg lists the setting for that particular variable. Specifying name and string, stores the string into variable name. Also See the section on special _variables. SLEEP Usage : sleep timeout example : sleep 10 Sleep for 'timeout' seconds, or until ^C typed. STRHEAD Usage : strhead varname breakchar string example : strhead j . foobar.bas echo $j result : foobar Remove everything after and including the breakchar in 'string' and place in variable 'varname'. STRTAIL Usage : strtail varname breakchar string example : strtail j . foobar.bas echo $j result : bas Remove everything before and including the breakchar in 'string' and place in variable 'varname'. SOURCE Usage : source file [arguments] example : source do_assigns all result : source file 'do_assigns' called with var _passed = 'all' 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 UNALIAS Usage : unalias name .. name example : unalias vt Delete aliases.. UNSET Usage : unset name .. name example : unset abc Unset one or more variables. Deletes them entirely. VER Usage : ver Show current version name, & authors. IX. SPECIAL SET VARIABLES --------------------- _prompt This variable is set to the command you wish executed that will create your prompt. This can contain escape sequences if you wish. The if command will set the prompt to a '_ ' if commands are disabled while waiting for a 'endif' or 'else' command. Interactive mode only. _history This variable is set to a numerical value, and specifies how far back your history should extend. _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:,df1:c/,df0:c/,ram:,ram:c/" When using 'run' command Shell will now use it's own search path first to find the command to run. If it fails to find the command (but the Run command was found) it executes the command line anyway to let amigaDos search path take over. _insert Set's the default for insert/overtype mode for command line editing. ^A toggles between, but after <RET> the default is set back as indicated by this variable. By default _insert is 1 indicating insert mode on setting to zero will make overtype the default. _width Indicates the console window width, 77 if unset. Will change automatically if the user resizes the window. X. ADVANCED TOPICS --------------- 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" XI. EXAMPLE .login file ------------------- from a CLI or the startup-script say 'SHELL filename'. That file is sourced first. thus, 'SHELL .login' will set up your favorite aliases: # -Steve's .login file- # echo -n "Enter Date [DD-MMM-YY HH:MM] ";input new; DATE $new # ------My search path ------- # set _path ram:c/,ram:,c:,df0:c/,df1:c/,sys:system/,sys:utilities # -------Function keys-------- # set f1 dir df0:^M set f2 dir df1:^M set F1 dir -s df0:^M set F2 dir -s df1:^M set f3 info^M set f4 ps^M # ---------Quickies---------- # # -query delete- # #another favorite eg qd *.c alias qd "%q foreach i ( $q ) \"echo -n Delete [n] ;input a;if $a = y;del $i;endif\"" alias delete rm alias rename mv alias makedir mkdir alias type cat alias print "%q copy $q prt:" alias info "devinfo df0: df1: ram:" alias tosys "assign c: SYS:c" alias toram "assign c: RAM:c;" alias tomanx "assign c: MANX:c; manxinit" alias d "dir -s" alias clr "echo -n ^l" alias wb "loadwb" alias pref "sys:preferences" alias cal "run sys:utilities/calculator" # ------Applications---------- # alias em "run emacs" alias vt "run sys:c/VT100" # --------Finish Up----------- # ver ;echo -n "Shell loaded on ";date XII. Example Source file ------------------- # ---- MANXINIT.SH ------ # SET INCLUDE=AC:include CCTEMP=ram: makedir ram:lib;Set CLIB=RAM:lib/;copy AC:lib/$libfile ram:lib" alias cleanup "del >NIL: ram:lib/* ram:lib" #run make in background at lower priority: alias make "%q run ChangeTaskPri -5 +^J^J MAKE $q"