NaSe77 has asked for the wisdom of the Perl Monks concerning the following question:

since my chef wants to use a script i have written on a win2000 machine i have to work a bit on it. there rests this one little problem: how to escape characters like spaces to pass as argument to another script:

i have written a little code to make the problem more obvious:

  • tell.pl 
    use strict;
use warnings;

my $string1 = " koisqd / \ poqsdpo .posd";
my $string2 = " koisqd / \ poqsdpo .posd";
my $string3 = " koisqd / \ poqsdpo .posd";

foreach my $toEscape ($string1, $string2, $string3){
        $toEscape =~ s/(\s|\\|\/)/\\$1/g;
}

system("perl hear.pl $string1 $string2 $string3");

    [download]
  • hear.pl 
    use strict;
use warnings;

my $i = 1;
foreach my $arg (@ARGV){
        print "$i\t: $arg\n";
        $i++;
}

    [download]
    wich gives me: 
    1       : \
2       : koisqd\
3       : \/\
4       : \
5       : poqsdpo\
6       : .posd
7       : \
8       : koisqd\
9       : \/\
10      : \
11      : poqsdpo\
12      : .posd
13      : \
14      : koisqd\
15      : \/\
16      : \
17      : poqsdpo\
18      : .posd

    [download]
    instead of just 3 arguments...

    please help me

    ----
    NaSe
    :x

    • Replies are listed 'Best First'.
    Re: Escaping characters on win2000's cmd.exe
    by PodMaster (Abbot) on Aug 22, 2002 at 12:20 UTC
      1. you bust out your shell's manual, and learn that it ain't *nix (you can't escape spaces, you need to "quote" stuff).

      2. this is also documented in perlrun, don't you ever perl -e " die scalar gmtime " ? 

      my $arg = q{butteer "scotch"};
$arg =~ s{"}{\\"}g;
system (qq{blah "$arg" ....});

      [download]
      update: also, perldoc -f system

      ____________________________________________________
      ** The Third rule of perl club is a statement of fact: pod is sexy.

    		[reply]
    [d/l]
        thanks that helped and it works now

        ----
        NaSe
        :x

    		[reply]
    Re: Escaping characters on win2000's cmd.exe
    by JupiterCrash (Monk) on Aug 22, 2002 at 13:08 UTC
      In addition to just quoting the arguments, which is a good start, you should note that perl's system command can accept an array as its argument. Like this:

      @args = ("command", "arg1", "arg2");
      system(@args);

      This is a nice solution, because then you don't have to worry about escaping things (like quotes) that the OS does not like in the arguments themselves.
    		[reply]

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