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| 1 | +# $Id: ShellQuote.pm,v 1.11 2010-06-11 20:08:57 roderick Exp $ |
| 2 | +# |
| 3 | +# Copyright (c) 1997 Roderick Schertler. All rights reserved. This |
| 4 | +# program is free software; you can redistribute it and/or modify it |
| 5 | +# under the same terms as Perl itself. |
| 6 | + |
| 7 | +=head1 NAME |
| 8 | +
|
| 9 | +String::ShellQuote - quote strings for passing through the shell |
| 10 | +
|
| 11 | +=head1 SYNOPSIS |
| 12 | +
|
| 13 | + $string = shell_quote @list; |
| 14 | + $string = shell_quote_best_effort @list; |
| 15 | + $string = shell_comment_quote $string; |
| 16 | +
|
| 17 | +=head1 DESCRIPTION |
| 18 | +
|
| 19 | +This module contains some functions which are useful for quoting strings |
| 20 | +which are going to pass through the shell or a shell-like object. |
| 21 | +
|
| 22 | +=over |
| 23 | +
|
| 24 | +=cut |
| 25 | + |
| 26 | +package String::ShellQuote; |
| 27 | + |
| 28 | +use strict; |
| 29 | +use vars qw($VERSION @ISA @EXPORT); |
| 30 | + |
| 31 | +require Exporter; |
| 32 | + |
| 33 | +$VERSION = '1.04'; |
| 34 | +@ISA = qw(Exporter); |
| 35 | +@EXPORT = qw(shell_quote shell_quote_best_effort shell_comment_quote); |
| 36 | + |
| 37 | +sub croak { |
| 38 | + require Carp; |
| 39 | + goto &Carp::croak; |
| 40 | +} |
| 41 | + |
| 42 | +sub _shell_quote_backend { |
| 43 | + my @in = @_; |
| 44 | + my @err = (); |
| 45 | + |
| 46 | + if (0) { |
| 47 | + require RS::Handy; |
| 48 | + print RS::Handy::data_dump(\@in); |
| 49 | + } |
| 50 | + |
| 51 | + return \@err, '' unless @in; |
| 52 | + |
| 53 | + my $ret = ''; |
| 54 | + my $saw_non_equal = 0; |
| 55 | + foreach (@in) { |
| 56 | + if (!defined $_ or $_ eq '') { |
| 57 | + $_ = "''"; |
| 58 | + next; |
| 59 | + } |
| 60 | + |
| 61 | + if (s/\x00//g) { |
| 62 | + push @err, "No way to quote string containing null (\\000) bytes"; |
| 63 | + } |
| 64 | + |
| 65 | + my $escape = 0; |
| 66 | + |
| 67 | + # = needs quoting when it's the first element (or part of a |
| 68 | + # series of such elements), as in command position it's a |
| 69 | + # program-local environment setting |
| 70 | + |
| 71 | + if (/=/) { |
| 72 | + if (!$saw_non_equal) { |
| 73 | + $escape = 1; |
| 74 | + } |
| 75 | + } |
| 76 | + else { |
| 77 | + $saw_non_equal = 1; |
| 78 | + } |
| 79 | + |
| 80 | + if (m|[^\w!%+,\-./:=@^]|) { |
| 81 | + $escape = 1; |
| 82 | + } |
| 83 | + |
| 84 | + if ($escape |
| 85 | + || (!$saw_non_equal && /=/)) { |
| 86 | + |
| 87 | + # ' -> '\'' |
| 88 | + s/'/'\\''/g; |
| 89 | + |
| 90 | + # make multiple ' in a row look simpler |
| 91 | + # '\'''\'''\'' -> '"'''"' |
| 92 | + s|((?:'\\''){2,})|q{'"} . (q{'} x (length($1) / 4)) . q{"'}|ge; |
| 93 | + |
| 94 | + $_ = "'$_'"; |
| 95 | + s/^''//; |
| 96 | + s/''$//; |
| 97 | + } |
| 98 | + } |
| 99 | + continue { |
| 100 | + $ret .= "$_ "; |
| 101 | + } |
| 102 | + |
| 103 | + chop $ret; |
| 104 | + return \@err, $ret; |
| 105 | +} |
| 106 | + |
| 107 | +=item B<shell_quote> [I<string>]... |
| 108 | +
|
| 109 | +B<shell_quote> quotes strings so they can be passed through the shell. |
| 110 | +Each I<string> is quoted so that the shell will pass it along as a |
| 111 | +single argument and without further interpretation. If no I<string>s |
| 112 | +are given an empty string is returned. |
| 113 | +
|
| 114 | +If any I<string> can't be safely quoted B<shell_quote> will B<croak>. |
| 115 | +
|
| 116 | +=cut |
| 117 | + |
| 118 | +sub shell_quote { |
| 119 | + my ($rerr, $s) = _shell_quote_backend @_; |
| 120 | + |
| 121 | + if (@$rerr) { |
| 122 | + my %seen; |
| 123 | + @$rerr = grep { !$seen{$_}++ } @$rerr; |
| 124 | + my $s = join '', map { "shell_quote(): $_\n" } @$rerr; |
| 125 | + chomp $s; |
| 126 | + croak $s; |
| 127 | + } |
| 128 | + return $s; |
| 129 | +} |
| 130 | + |
| 131 | +=item B<shell_quote_best_effort> [I<string>]... |
| 132 | +
|
| 133 | +This is like B<shell_quote>, excpet if the string can't be safely quoted |
| 134 | +it does the best it can and returns the result, instead of dying. |
| 135 | +
|
| 136 | +=cut |
| 137 | + |
| 138 | +sub shell_quote_best_effort { |
| 139 | + my ($rerr, $s) = _shell_quote_backend @_; |
| 140 | + |
| 141 | + return $s; |
| 142 | +} |
| 143 | + |
| 144 | +=item B<shell_comment_quote> [I<string>] |
| 145 | +
|
| 146 | +B<shell_comment_quote> quotes the I<string> so that it can safely be |
| 147 | +included in a shell-style comment (the current algorithm is that a sharp |
| 148 | +character is placed after any newlines in the string). |
| 149 | +
|
| 150 | +This routine might be changed to accept multiple I<string> arguments |
| 151 | +in the future. I haven't done this yet because I'm not sure if the |
| 152 | +I<string>s should be joined with blanks ($") or nothing ($,). Cast |
| 153 | +your vote today! Be sure to justify your answer. |
| 154 | +
|
| 155 | +=cut |
| 156 | + |
| 157 | +sub shell_comment_quote { |
| 158 | + return '' unless @_; |
| 159 | + unless (@_ == 1) { |
| 160 | + croak "Too many arguments to shell_comment_quote " |
| 161 | + . "(got " . @_ . " expected 1)"; |
| 162 | + } |
| 163 | + local $_ = shift; |
| 164 | + s/\n/\n#/g; |
| 165 | + return $_; |
| 166 | +} |
| 167 | + |
| 168 | +1; |
| 169 | + |
| 170 | +__END__ |
| 171 | +
|
| 172 | +=back |
| 173 | +
|
| 174 | +=head1 EXAMPLES |
| 175 | +
|
| 176 | + $cmd = 'fuser 2>/dev/null ' . shell_quote @files; |
| 177 | + @pids = split ' ', `$cmd`; |
| 178 | +
|
| 179 | + print CFG "# Configured by: ", |
| 180 | + shell_comment_quote($ENV{LOGNAME}), "\n"; |
| 181 | +
|
| 182 | +=head1 BUGS |
| 183 | +
|
| 184 | +Only Bourne shell quoting is supported. I'd like to add other shells |
| 185 | +(particularly cmd.exe), but I'm not familiar with them. It would be a |
| 186 | +big help if somebody supplied the details. |
| 187 | +
|
| 188 | +=head1 AUTHOR |
| 189 | +
|
| 190 | +Roderick Schertler <F<[email protected]>> |
| 191 | +
|
| 192 | +=head1 SEE ALSO |
| 193 | +
|
| 194 | +perl(1). |
| 195 | +
|
| 196 | +=cut |
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