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

6       shell-quote - quote arguments for safe use, unmodified in a shell com‐
7       mand
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SYNOPSIS

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

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

19       ssh preserving args
20           When running a remote command with ssh, ssh doesn't preserve the
21           separate arguments it receives.  It just joins them with spaces and
22           passes them to "$SHELL -c".  This doesn't work as intended:
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24               ssh host touch 'hi there'           # fails
25
26           It creates 2 files, hi and there.  Instead, do this:
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28               cmd=`shell-quote touch 'hi there'`
29               ssh host "$cmd"
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31           This gives you just 1 file, hi there.
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33       process find output
34           It's not ordinarily possible to process an arbitrary list of files
35           output by find with a shell script.  Anything you put in $IFS to
36           split up the output could legitimately be in a file's name.  Here's
37           how you can do it using shell-quote:
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39               eval set -- `find -type f -print0 ⎪ xargs -0 shell-quote --`
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41       debug shell scripts
42           shell-quote is better than echo for debugging shell scripts.
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44               debug() {
45                   [ -z "$debug" ] ⎪⎪ shell-quote "debug:" "$@"
46               }
47
48           With echo you can't tell the difference between "debug 'foo bar'"
49           and "debug foo bar", but with shell-quote you can.
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51       save a command for later
52           shell-quote can be used to build up a shell command to run later.
53           Say you want the user to be able to give you switches for a command
54           you're going to run.  If you don't want the switches to be re-eval‐
55           uated by the shell (which is usually a good idea, else there are
56           things the user can't pass through), you can do something like
57           this:
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59               user_switches=
60               while [ $# != 0 ]
61               do
62                   case x$1 in
63                       x--pass-through)
64                           [ $# -gt 1 ] ⎪⎪ die "need an argument for $1"
65                           user_switches="$user_switches "`shell-quote -- "$2"`
66                           shift;;
67                       # process other switches
68                   esac
69                   shift
70               done
71               # later
72               eval "shell-quote some-command $user_switches my args"
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OPTIONS

75       --debug
76           Turn debugging on.
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78       --help
79           Show the usage message and die.
80
81       --version
82           Show the version number and exit.
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AVAILABILITY

85       The code is licensed under the GNU GPL.  Check
86       http://www.argon.org/~roderick/ or CPAN for updated versions.
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AUTHOR

89       Roderick Schertler <roderick@argon.org>
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93perl v5.8.8                       2005-05-03                    SHELL-QUOTE(1)
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