table of contents
SHELL-QUOTE(1p) | User Contributed Perl Documentation | SHELL-QUOTE(1p) |
NAME¶
shell-quote - quote arguments for safe use, unmodified in a shell commandSYNOPSIS¶
shell-quote [switch]... arg...DESCRIPTION¶
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.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 "$SHELL -c". This doesn't work as
intended:
ssh host touch 'hi there' # fails
cmd=`shell-quote touch 'hi there'` ssh host "$cmd"
- 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:" "$@" }
- 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:
user_switches= while [ $# != 0 ] do case x$1 in x--pass-through) [ $# -gt 1 ] ⎪⎪ die "need an argument for $1" user_switches="$user_switches "`shell-quote -- "$2"` shift;; # process other switches esac shift done # later eval "shell-quote some-command $user_switches my args"
OPTIONS¶
- --debug
- Turn debugging on.
- --help
- Show the usage message and die.
- --version
- Show the version number and exit.
AVAILABILITY¶
The code is licensed under the GNU GPL. Check http://www.argon.org/~roderick/ or CPAN for updated versions.AUTHOR¶
Roderick Schertler <roderick@argon.org>2005-05-03 | perl v5.8.4 |