Garbo/Garbo.cdr/pc/unix/ma_rm14.arc/RM.DOC

Text File | 1989-10-21 | 6.0 KB | 181 lines

RM.COM by Mark Adler  Pasadena, CA  1988,1989.


RM is an extended delete command.  It can delete all the files in a
directory and its subdirectories, etc. and remove all the directories.
Alternatively, it can delete all the files in any directories that match
the specified pattern.  Since RM is a more powerful delete command, it
can be that much more dangerous.  So the following warning is in order:

WARNING:  RM IS A VERY DESTRUCTIVE COMMAND.  It will NOT ask for
verification of a particularily destructive argument like the DOS DEL
command does.  What you ask it is what it does.  BE CAREFUL.

Normally, RM acts like the DEL command, deleting any files that match
the pattern, except that it does not verify the argument *.*---it just
does it.  For example:

     rm *.bak

will delete all the *.bak files in the current directory.  The command:

     rm *.*

will delete all the files in the current directory without asking first.

RM can also delete the contents of subdirectories and then remove the
subdirectories.  The option for this is "/S".  For example:

     rm/s \tex

will delete all the files and subdirectories contained in \tex and
finally remove the directory \tex.  The command:

     rm/s \tex\*.*

will do the same thing, but not remove the directory tex, just
everything in it.

Alternatively, RM can delete any files that match the pattern in all
subdirectories.  The option for this is "/F":

     rm/f \*.bak

will delete all *.bak files on the current drive, no matter where they
are.  No subdirectories will be removed.

If you think that's dangerous, RM can also remove hidden, system, or
read-only files if asked to.  The options are "/H", "/Y", and "/R".
For example:

     rm/shyr \*.*               DON'T EVEN THINK OF TYPING THIS COMMAND.

will remove every single file and directory on the current drive,
including the system---leaving only the drive label, a lot of empty
space, and a user in a state of panic.

RM can take multiple arguments, processing each in turn.  For example:

     rm *.obj *.lst *.map

will delete all the files specified.

RM does have one option that makes it a little less dangerous; "/P".
This option causes RM to prompt you for every file or directory it tries
to get rid of.  For example:

     rm/p *.*

might ask you:

     Delete file test.c (y/n)? _

or

     Remove directory \tmp (y/n)? _

In either case, you must respond with either an upper or lower case "Y"
or "N".  Any other response is ignored.

When it is done, RM will tell you how many files it deleted and how many
directories it removed.  It might say, for example:

     13 files deleted

or

     129 files deleted and 4 directories removed

If RM is, for some reason, unable to delete a file or remove a
directory, it will say:

     Could not delete file test.c

or

     Could not remove directory \tmp - part of current path

or

     Could not remove directory \tmp - unable to empty it

It should not be possible to get the first error.  The second error
occurs when the directory RM tried to remove is part of the current path
for that drive.  DOS does not allow pulling the rug out from under your
feet by removing a directory you are in.  The remedy is to change out of
the directory you wish to remove and repeating the RM command.

The third error can happen when RM tries to remove a directory with
read-only, hidden, or system files in it, and no options were specified
to allow RM to remove those.  The remedy is to repeat the RM command
with the necessary options to delete the files desired.

RM takes options that are preceded by a slash (/).  The command line is
read from left to right, processing options and file/path names as they
appear.  However, options that are appended to a file/path name take
effect before that name is processed.  For example, this command would
do the same thing as "rm/p *.c":

     rm *.c/p

But the command "rm *.c /p" (notice the extra space before the /p) would
not do the same thing.  In this case, RM notices the "dangling" option
before it does anything and simply ignores the entire command for
safety, printing:

    Dangling option---entire command ignored

Since there are options to change the defaults along a command line,
there are options to change them back for processing the next thing
on the command line.  All the options are listed here:

     /P  - Prompt for each deletion or removal.
     /Q  - Quiet---don't prompt (default).
     /S  - Remove matching subdirectories and all of their contents.
     /N  - Ignore subdirectories (default).
     /H  - Remove hidden files.
     /V  - Visible---ignore hidden files (default).
     /Y  - Remove system files.
     /T  - Typical---ignore system files (default).
     /R  - Remove read-only files!
     /W  - Only delete writable files (default).
     /F  - Remove all files that match pattern, and no subdirs.
     /A  - Remove all files in subdirectories, period (default).
     /?  - Display version number and list of options.

For example, the command:

     rm /p *.lst /q *.obj

will ask before deleting each file that matches *.lst, and then delete
all the files that match *.obj without asking.

Options can be combined with or without additional slashes.  For
example, these commands do the same thing:

     rm *.lst/pr
     rm/p/r *.lst
     rm /p /r *.lst
     rm /p *.lst/r

Once again---BE CAREFUL WITH THIS COMMAND.  Thanks to Kurt Schmidt for
suggesting that RM be changed to notice a dangling option.


Version history -

1.0      4 Jun 1988     First public version
1.1      4 Nov 1988     Make rm as fast as del (use FCB delete)
1.2     18 Nov 1988     Fixed for Turbo C 2.0 (label needs statement)
1.3      3 Feb 1989     Display files and directories in lower case
1.4     21 Oct 1989     Catch dangling options and ignore command


Feel free to send any problems with or comments on RM to:

        Mark Adler
        P.O. Box 60998
        Pasadena, CA  91116