Why does `rm -f !(/var/www/wp)` leave files behind in /var/www?

Question

Why does the rm -f !(/var/www/wp) command have no effect? I want to remove all the files in /var/www, except for the /var/www/wp directory, which should remain.

root@born:~# ls  /var/www
authorize.php  index.html          INSTALL.txt      README.txt  UPGRADE.txt
CHANGELOG.txt  index.php           LICENSE.txt      robots.txt  web.config
COPYRIGHT.txt  INSTALL.mysql.txt   MAINTAINERS.txt  scripts wp
cron.php       INSTALL.pgsql.txt   misc             sites       xmlrpc.php
drupal         install.php         modules          themes
includes       INSTALL.sqlite.txt  profiles         update.php
root@born:~# rm  -f  !(/var/www/wp)
root@born:~# ls  /var/www
authorize.php  index.html          INSTALL.txt      README.txt  UPGRADE.txt
CHANGELOG.txt  index.php           LICENSE.txt      robots.txt  web.config
COPYRIGHT.txt  INSTALL.mysql.txt   MAINTAINERS.txt  scripts wp
cron.php       INSTALL.pgsql.txt   misc             sites       xmlrpc.php
drupal         install.php         modules          themes
includes       INSTALL.sqlite.txt  profiles         update.php

Are you sure that !(/var/www/wp) is a shell construct that actually exists? Do you have a pointer to where that's documented? I have never heard of it, and it I try it on bash over here !(/var/www/wp) just gets interpreted as !(/var/www/wp) (literally) so your command would try to delete a file called !(/var/www/wp). — Celada, Mar 20 '15 at 04:28
/var/www/wp is a directory not a file not a link .i want to keep the directory ,all other files and directories removed. — showkey, Mar 20 '15 at 04:32
@Celada !(/var/www/wp) is a bash extglob which is a feature that can be turned on or off with shopt. — John1024, Mar 20 '15 at 04:36
A directory won't be deleted by rm anyway! rm only works on files, it will just warn you that you gave directories as arguments. So... always ask the right questions. Secondly, why don't you cd there before removing stuff? What you are doing is extermely dangerous and you may have damaged your home directory. Read the answer by Michael. — orion, Mar 20 '15 at 08:07

score 37 · Answer 1 · edited Mar 20 '15 at 21:35

37

If you're running bash ≥4.3, then if you have backups, now would be a good time to find them.

I assume you're using Bash. The !(...) filename expansion pattern expands to every existing path that doesn't match the pattern at the point it's used. That is:

echo rm  -f  !(/var/www/wp)

expands to every filename in the current directory that isn't "/var/www/wp". That is every file in the current directory. In essence, you ran rm -f * in ~. Do not run the rm command above.

To get the effect you wanted, use the pattern only for the part of the path you want it (not) to match, just like you would for *, {a,b,c}, or any other pattern. The command:

echo rm -f /var/www/!(wp)

will print out the command you wanted to run.

I don't, to be honest, suggest doing things this way - it's prone to exactly the sort of issue you had here, and others. Something with find is easier to follow. At the very least, echo the command before you run it and you'll see what is happening.

edited Mar 20 '15 at 21:35

Gilles 'SO- stop being evil'

829,060

answered Mar 20 '15 at 04:35

Michael Homer

76,565

1

This won't remove hidden files and directories. – cuonglm Mar 20 '15 at 04:46
2

Good answer. I'd also add this: at least cd to the directory before removing anything. Removing things from far away is always dangerous (especially if there are relative paths or globs involved). – orion Mar 20 '15 at 08:04
On what version of bash did you see this? On ksh 93u+ and on bash 4.2 with shopt -s extglob, echo !(/var/www/wp) leaves the pattern unchanged, as does as far as I can tell any pattern where a slash is within !(…) – Gilles 'SO- stop being evil' Mar 20 '15 at 21:27
@Gilles: GNU bash, version 4.3.33(1)-release (x86_64-unknown-linux-gnu) – Michael Homer Mar 20 '15 at 21:30
But you're right, 3.2 doesn't do it. It does seem like a misfeature to have added that behaviour. – Michael Homer Mar 20 '15 at 21:35
Thanks. That's a weird incompatible change — departing from ksh, zsh, and previous versions of bash, to do something which I can't fathom being useful. The behavior of !(…) changed in bash 4.3, but I don't get the impression that matching all files in the current directory with a pattern like !(/) was intended. – Gilles 'SO- stop being evil' Mar 20 '15 at 21:36

score 9 · Accepted Answer · edited Apr 13 '17 at 12:37

9

You can read Michael Homer's answer to know the reason.

To remove all things in /var/www exclude wp, POSIXly:

find /var/www -path /var/www/wp -prune -o ! -path /var/www -exec rm -rf {} +

edited Apr 13 '17 at 12:37

Community

1

answered Mar 20 '15 at 04:39

cuonglm

153,898

score 0 · Answer 3 · answered Mar 20 '15 at 23:56

Find, grep and xargs combination

find /var/www/ -maxdepth 1|grep -v wp|xargs rm -rf

And can be convert into bash file, for more generalized purpose.

#!bash
# $1 -- directory 
# $2 -- Exception filename or directory name
find "$1" -maxdepth 1|grep -v "$2"|xargs rm -rf

score -2 · Answer 4 · answered Mar 21 '15 at 05:40

 user@host:~$ rm --help
Usage: rm [OPTION]... FILE...
Remove (unlink) the FILE(s).

  -f, --force           ignore nonexistent files and arguments, never prompt
  -i                    prompt before every removal
  -I                    prompt once before removing more than three files, or
                          when removing recursively.  Less intrusive than -i,
                          while still giving protection against most mistakes
      --interactive[=WHEN]  prompt according to WHEN: never, once (-I), or
                          always (-i).  Without WHEN, prompt always
      --one-file-system  when removing a hierarchy recursively, skip any
                          directory that is on a file system different from
                          that of the corresponding command line argument
      --no-preserve-root  do not treat '/' specially
      --preserve-root   do not remove '/' (default)
  -r, -R, --recursive   remove directories and their contents recursively
  -d, --dir             remove empty directories
  -v, --verbose         explain what is being done
      --help     display this help and exit
      --version  output version information and exit

By default, rm does not remove directories.  Use the --recursive (-r or -R)
option to remove each listed directory, too, along with all of its contents.

To remove a file whose name starts with a '-', for example '-foo',
use one of these commands:
  rm -- -foo

  rm ./-foo

Note that if you use rm to remove a file, it might be possible to recover
some of its contents, given sufficient expertise and/or time.  For greater
assurance that the contents are truly unrecoverable, consider using shred.

Report rm bugs to bug-coreutils@gnu.org
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
For complete documentation, run: info coreutils 'rm invocation'

Idea for a workaround:

:~$

cd /var/www
    mkdir /opt/move
    mv wp /opt/move/wp
    rm -r *
    mv /opt/wp /var/www/wp
[optional ;)] chown -R www-data:www-data /var/www

user@host:~$ mv Reference:

mv --help
Usage: mv [OPTION]... [-T] SOURCE DEST
  or:  mv [OPTION]... SOURCE... DIRECTORY
  or:  mv [OPTION]... -t DIRECTORY SOURCE...
Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY.

Mandatory arguments to long options are mandatory for short options too.
      --backup[=CONTROL]       make a backup of each existing destination file
  -b                           like --backup but does not accept an argument
  -f, --force                  do not prompt before overwriting
  -i, --interactive            prompt before overwrite
  -n, --no-clobber             do not overwrite an existing file
If you specify more than one of -i, -f, -n, only the final one takes effect.
      --strip-trailing-slashes  remove any trailing slashes from each SOURCE
                                 argument
  -S, --suffix=SUFFIX          override the usual backup suffix
  -t, --target-directory=DIRECTORY  move all SOURCE arguments into DIRECTORY
  -T, --no-target-directory    treat DEST as a normal file
  -u, --update                 move only when the SOURCE file is newer
                                 than the destination file or when the
                                 destination file is missing
  -v, --verbose                explain what is being done
      --help     display this help and exit
      --version  output version information and exit

The backup suffix is '~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX.
The version control method may be selected via the --backup option or through
the VERSION_CONTROL environment variable.  Here are the values:

  none, off       never make backups (even if --backup is given)
  numbered, t     make numbered backups
  existing, nil   numbered if numbered backups exist, simple otherwise
  simple, never   always make simple backups

Report mv bugs to bug-coreutils@gnu.org
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
For complete documentation, run: info coreutils 'mv invocation'

user@host:~$ chown Reference:

chown --help                                                                                                                              
    Usage: chown [OPTION]... [OWNER][:[GROUP]] FILE...                                                                                                           
      or:  chown [OPTION]... --reference=RFILE FILE...                                                                                                           
    Change the owner and/or group of each FILE to OWNER and/or GROUP.                                                                                            
    With --reference, change the owner and group of each FILE to those of RFILE.                                                                                 

      -c, --changes          like verbose but report only when a change is made                                                                                  
      -f, --silent, --quiet  suppress most error messages                                                                                                        
      -v, --verbose          output a diagnostic for every file processed                                                                                        
          --dereference      affect the referent of each symbolic link (this is                                                                                  
                             the default), rather than the symbolic link itself                                                                                  
      -h, --no-dereference   affect symbolic links instead of any referenced file                                                                                
                             (useful only on systems that can change the                                                                                         
                             ownership of a symlink)                                                                                                             
          --from=CURRENT_OWNER:CURRENT_GROUP                                                                                                                     
                             change the owner and/or group of each file only if                                                                                  
                             its current owner and/or group match those specified                                                                                
                             here.  Either may be omitted, in which case a match                                                                                 
                             is not required for the omitted attribute                                                                                           
          --no-preserve-root  do not treat '/' specially (the default)                                                                                           
          --preserve-root    fail to operate recursively on '/'                                                                                                  
          --reference=RFILE  use RFILE's owner and group rather than                                                                                             
                             specifying OWNER:GROUP values
      -R, --recursive        operate on files and directories recursively

    The following options modify how a hierarchy is traversed when the -R
    option is also specified.  If more than one is specified, only the final
    one takes effect.

      -H                     if a command line argument is a symbolic link
                             to a directory, traverse it
      -L                     traverse every symbolic link to a directory
                             encountered
      -P                     do not traverse any symbolic links (default)

          --help     display this help and exit
          --version  output version information and exit

    Owner is unchanged if missing.  Group is unchanged if missing, but changed
    to login group if implied by a ':' following a symbolic OWNER.
    OWNER and GROUP may be numeric as well as symbolic.

    Examples:
      chown root /u        Change the owner of /u to "root".
      chown root:staff /u  Likewise, but also change its group to "staff".
      chown -hR root /u    Change the owner of /u and subfiles to "root".

    Report chown bugs to bug-coreutils@gnu.org
    GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
    General help using GNU software: <http://www.gnu.org/gethelp/>
    For complete documentation, run: info coreutils 'chown invocation'

Why does `rm -f !(/var/www/wp)` leave files behind in /var/www?

4 Answers4

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