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SHELL-QUOTE(1)        User Contributed Perl Documentation       SHELL-QUOTE(1)

       shell-quote - quote arguments for safe use, unmodified in a shell command

       shell-quote [switch]... arg...

       shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell.  This
       lets you process commands or files with embedded white space or shell globbing characters safely.  Here are a
       few examples.

       ssh preserving args
           When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives.  It just
           joins them with spaces and passes them to "$SHELL -c".  This doesn't work as intended:

               ssh host touch 'hi there'           # fails

           It creates 2 files, hi and there.  Instead, do this:

               cmd=`shell-quote touch 'hi there'`
               ssh host "$cmd"

           This gives you just 1 file, hi there.

       process find output
           It's not ordinarily possible to process an arbitrary list of files output by find with a shell script.
           Anything you put in $IFS to split up the output could legitimately be in a file's name.  Here's how you can
           do it using shell-quote:

               eval set -- `find -type f -print0 | xargs -0 shell-quote --`

       debug shell scripts
           shell-quote is better than echo for debugging shell scripts.

               debug() {
                   [ -z "$debug" ] || shell-quote "debug:" "$@"

           With echo you can't tell the difference between "debug 'foo bar'" and "debug foo bar", but with shell-quote
           you can.

       save a command for later
           shell-quote can be used to build up a shell command to run later.  Say you want the user to be able to give
           you switches for a command you're going to run.  If you don't want the switches to be re-evaluated by the
           shell (which is usually a good idea, else there are things the user can't pass through), you can do
           something like this:

               while [ $# != 0 ]
                   case x$1 in
                           [ $# -gt 1 ] || die "need an argument for $1"
                           user_switches="$user_switches "`shell-quote -- "$2"`
                       # process other switches
               # later
               eval "shell-quote some-command $user_switches my args"

           Turn debugging on.

           Show the usage message and die.

           Show the version number and exit.

       The code is licensed under the GNU GPL.  Check or CPAN for updated versions.

       Roderick Schertler <>

perl v5.10.1                      2010-06-11                    SHELL-QUOTE(1)