parker@epiwrl.UUCP (01/24/87)
Could someone please send me the man page for the pc-shell that was posted some time back? Thanks. Alan Parker ...!seismo!epiwrl!parker
tron@slovax.UUCP (01/27/87)
> Could someone please send me the man page for the pc-shell that > was posted some time back? Thanks. > > Alan Parker > ...!seismo!epiwrl!parker Here is the man page for the pc-shell.... Enjoy. David Barker RDA Logicon Tacoma, WA SHELL.EXE command processor for ms.dos This is yet another command.com replacement. It implements unix-like shell commands (ls, mv, fgrep, rm, chdir, chmod) etc. Other features include: 1. Command line expansion of ambiguous file names. Programs invoked from shell never see '*.*' as an argument - they see the list of all matching files in the current directory. 2. History substitution - ala C-shell. History substitution is a powerful means to save retyping of long command lines.It allows you to do things like re-execute the last command, re-execute the last command but redirect output to a file, or execute a new command with arguments from previous command lines. The last 20 commands are saved, and can be reviewed by typing the 'history' command. Previous commands can be referred to by their number, or relative to the current command's number. Parameters from previous commands can be seperated out and used individually. History substitutions specifications come in two parts - the command number specifier and the argument specifier, seperated by a colon. The argument specifier is optional; if it is omitted, the entire command line is specified. <command specifier> ::= !! | !n | !-n !! = last command !n = nth command !-n = command n commands before current command number <argument specifier> ::= :[^$*] | :n | :n* | <empty> n = number of argument (0 being the command name) ^ = first argument (i.e. argv[1]) $ = last argument * = ^-$, or nothing if only one word on command line n* = arguments n through $ <history subst specification> ::= <command specifier><argument specifier> This is not as complicatated as it may appear. Here is an example session. 0% ls *.c *.c foo.c bar.c 1% more foo.c /* edit the last argument of the last command */ 2% edit !!:$ /* go off and edit */ /* reference last argument of last command */ 3% fgrep foo !!:$ bar.c FOO.C : foo BAR.C : foo /* edit the second thru the last args of command 3 */ 4% edit !3:2* (go off and edit) /* repeat last command */ %5 !! (go off and edit) /* remove the 1st argument of the command 2 before the current one */ %6 rm !-6:^ History substitution here is a compatible subset of the C-shells history substitution facility. Cshell allows even weirder combinations. 3. Multiple commands on one command line - Command lines are split at semicolons. example %0 ls -l *.c ; make shell.exe ; exit 4. Character escapes and argument quoting - i.e. '\;' suppresses the command parser from seeing the semicolon as a command seperator. Quotes are handles thusly: 1. String surrounded by single quotes are stripped of the single quotes, and passed without wild-card expansion to the invoked program. 2. Strings surrounded by double quotes are passed complete with quotes to the calling program. This was done for a version of grep that I have that accepts regular expressions with embedded blanks within double quotes. 5. Many builtin commands. Output of the 'commands' command a: b: c: cat cd chdir chmod cls commands copy cp copy d: del dir dump e: echo era erase error exit f: fgrep g: h: hd hist history i: j: ls md mkdir more mv no history popd pushd pwd rd rm rmdir set tee touch version y There are many that are simply aliases, e.g. 'copy' and 'cp' invoke the same program. 6. commands description syntax terms used in syntax explanations : fname ::= PC-DOS ambiguous or unambiguous file or directory name. uname ::= unambiguous PC-DOS file or directory name string ::= any string of printable characters of arbitrary(<512) length. filelist ::= filename [filename .. filename] noargs ::= no arguments at all {arg} ::= term is optional envstring ::= <string>=<string> 7. command syntax drive a: | b: | c: | d: | e: | f: | g: | h: | i: | j: <noargs> changes default drive. If you don't have such a drive, nothing happens. cat cat {<filelist>} copies specified files to standard output. If none are given, copies standard input to standard output cp cp | copy <filelist> <uname> copies specified files to destination file or device. If more than one file is in the file list, <uname> must be a directory. cd cd | chdir <dirname> makes <dirname> the current default directory. chmod chmod {-|+[rwh]*} <filelist> change file permissions for specified files +r, -r turn on or off read permission - i.e. hide the file. +w, -w turn on or off write permission. +h, -h turn on or off hidden attribute - converse of r +a, -a turn on or off archive attribute Note that '-r' or '+rwh' are both valid syntax for switches. Also new permission switches are permissable between file names with the following warning: I don't reset the masks between file names - if you have a second batch of attribute changes on the command line, the effect is additive. If you're not careful, you could make a mess of a files attributes. If you don't specify any attribute switches, file attributes will be set to 0, which means read,write,not hidden,not system, not modified since last backup. cls cls | clear <noargs> clears the screen and homes the cursor. commands commands <noargs> prints a table of available built-in commands. del del synonym for rm. dir dir synonym for ls. dump dump filespec [block [page]] | [segment:[offset]] [count] Where a block is 64K bytes and a page is 256 bytes Segment:offset are standard 8086 notation in hexadecimal Count is the number of bytes to dump in decimal This came from some anonymous public domain source, ported by me echo echo <anything> echos argument list to screen. era era synonym for rm. error error <noargs> prints returned value of last command to the screen. exit exit <noargs> terminates execution of the shell. fgrep fgrep <pattern> <filelist> looks for unambiguous pattern <pattern> in <filelist>. echos lines matching to the screen. hist hist | history <noargs> prints history list to standard output. ls ls | dir {-[alqcr]} <filelist> Lists files that match <filelist> -a all files, including system files are listed. '.' and '..' are suppressed, but you know they're there if you need them, don't you? -l prints out file times, permissions, etc -q suppresses header line from display - useful when you want to pipe stuff into another program. -c print as one column. -r recurse through all encountered subdirectories. md md | mkdir <uname> make a directory. Prints an error if it can't be done more more {-[0-9]*} {<filelist>} List file to screen with pauses -n specify tab width when expanding tabs, where n is an integer. more acts like 'cat' when redirected - you can concatenate files in this manner. If no files are specifed, standard input is 'mored.' mv mv <filelist> <uname> moves specified file or files to target specifed by <uname>. If there is more than one file in list, <uname> must be a directory popd popd <noargs> returns to directory at top of directory stack. pushd pushd <uname> save current working directory on directory stack, and changes current working directory to <uname>. pwd pwd prints current working directory to standard output. rd rd | rmdir <uname> remove specified directory if possible. rm rm {-q} <filelist> blows away all files in <filelist>. If -q is specified, will ask if they should be removed. set set {<envstring> {<envstring> .. <envstring>}} sets a string in the environment. If you specify 'name=' with no string after, it will remove it from the environment. If you don't specify a string, set prints out current environment. tee tee <uname> Copies standard input to standard output, depositing a copy in <uname> touch touch <filelist> Makes the modification time of specified files the current date and time. y y <filelist> copies standard input to standard output, and then copies the specified files to standard output. Sort of the opposite of tee, in other words. 7. Helpful hints Use forward slashes in all path names - they get converted to back slashes before dos hears about them. If you are invoking a program that expects forward slashes (dos external commands frinstance) precede it with a back slash. put single quotes around arguments with semicolons in them, so they don't turn into command delimiters. The set command affects only the local shell's environment. You can 'exit' to command.com and the original environment is intact. The local environment is 4K large - which is useful. Exit and re-invoke if you have trouble loading large programs from it - shell dynamically allocates and frees memory all the time, but the AZTEC run-time doesn't tell DOS to shrink memory 8. Implementation notes DOS doesn't acknowledge a 'change default drive' command until you issue a 'get current directory' call. Why? The only way I figured this out is by disassembling command.com. This was developed with AZTEC C by MANX. In it are a few hacked up pieces of AZTECS library source, which I hereby acknowledge. If MANX has a problem with me distributing them, they can call me direct - I figure I'm doing them a favor by disseminating this program as an example of the power and quality of their compiler and development tools. If you have the AZTEC compiler and MANX's version of make, you can recreate the shell from source, by using arc to unpack everything into a directory, editing the macros BINDIR and CLIB and then making shell.com. I wouldn't try it with any other compiler, because I make a lot of calls to AZTEC specific routines. You can write your own commands and add them by editing cmds.c, and putting the name of your subroutine and its associated command string into the builtin array. You can safely modify any of my builtins, as long as you don't assume that all of your static variables are going to stay initialized to startup values. Any of the other code (main.c, fexecvp.c fexecv.c) modify at your own peril. I break them every time I do it, and I wrote them!!! PC|MS-DOS has a limit of 20 file handles. If you add a command that opens files, make sure you catch the ctrl-break signal and close them. Look at CAT.C or Y.C for examples. 9. BUGS External DOS commands have trouble parsing the command line when invoked from shell. The command line gets garbled. I spent a lot of time trying to figure this problem out to no avail. They apparently get their command line arguments some way that is a mystery to me. The only solution is either to either run command.com, or 'exit' to the original command prompt. This problem has kept me from running this as a straight command.com replacement. It just goes to show that Microsoft and IBM have one hell of a time following their own rules. Programs compiled by AZTEC C that don't set up their own signal handlers seem to be 'unbreakable' - you can't ctrl-break out of them, as though SIGINT is set to SIG_IGN before entry. You might not want to invoke such a program if it lasts hours and you want to be able to break out of it. FIXED in current version. Thanks to AZTEC Tech Support. 10. HISTORY V 1.0 - Initial release Functional, but somewhat buggy. Lacked full history substitution. V 1.1 Added history substitution. Fixed some bugs. This has been floating around for a while. V 1.2 Fixed bugs. Added 'free space' display to ls -l. Minimized weird behavior of cp and mv. Did you know that PC-DOS doesn't think the root directory is a directory if you ask it? Caused much pain. QUESTIONS COMMENTS GOTO KENT WILLIAMS NORAND INC. 550 2nd ST. S.E. Cedar Rapids Iowa 52401 (319) 338-6053 (HOME VOICE)