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

Have a application where I need to send a command which needs to contain "\"

so the final string to send would be "blah blah item\ 0-9\ 10-14 more blah blah blah"

I have variable $object = 'item 0-9 10-14' 

# command template
$cmd ="blah blah $object blah blah";
 
( $output, $errput ) = $ssh->capture2( $cmd )
     or $logger->logdie( "Export failed: " . $ssh->error );

[download]

Replies are listed 'Best First'.
Re: Net::OpenSSH quoting problems
by salva (Canon) on May 13, 2014 at 06:33 UTC
    Net::OpenSSH can do all the quoting for you: 
    ($output, $errput) = $ssh->capture('blah', 'blah', $object, 'blah', 'b
+lah');

    [download]
    Or if you want to keep the command template as it is: 
    my $quoted_object = $ssh->shell_quote($object);
$cmd = "blah blah $quoted_object blah blah";
($output, $errput) = $ssh->capture2($cmd);

    [download]
    Read the Shell quoting section on the module documentation.
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      Found the problems - double faceslap 1. The squishy thing between the chair and the keyboard. incorrectly capitaltised word 2. One box I was testing on didn't have the latest software and didn't support the command I was trying to use
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Re: Net::OpenSSH quoting problems
by kcott (Archbishop) on May 13, 2014 at 03:25 UTC

    G'day jhuijsing,

    You haven't actually asked a question, so I don't know exactly which part of this you're having difficulties with.

    If you just want to know how to get from 'item 0-9 10-14' to 'item\ 0-9\ 10-14', you can do it like this: 

    #!/usr/bin/env perl -l

use strict;
use warnings;

my $object = 'item 0-9 10-14';
print $object;
$object =~ s/( \d+-\d+)/\\$1/g;
print $object;

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    Output:

    item 0-9 10-14
item\ 0-9\ 10-14

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    If you wanted something else, please specify.

    -- Ken

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      That doesn't work 
      #with the debug flag set
$Net::OpenSSH::debug |= 16;

$object =~ s/( \d+-\d+)/\\$1/g;
$cmd = qq|blah blah $object blah blah|;

( $output, $errput ) = $ssh->capture2(  $cmd )
              or $logger->logdie( "bad".$ssh->error );


using the debugger
x $object
item 0-7 0-9
after substitution
x $object             
item \\ 0-7\\ 0-9'
# lot of stuff removed the 
#open_ex  ......  'blah blah item\\ 0-7\\ 0-9

      [download]
      It sending a \\ not "item\ 0-7\ 0-9"
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        This works for me: 
          DB<5>  $object = "2-4 5-12"

  DB<6>  $object =~ s/([-\d]+)/\\$1/g

  DB<7> p $object
\2-4 \5-12

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        Or you could store the backslash in a variable and use that variable: 
          DB<11>  $c = '\\';

  DB<12> p $c
\
  DB<13>  $object = "2-4 5-12"

  DB<14> $object =~ s/([-\d]+)/$c$1/g;

  DB<15> p $object
\2-4 \5-12

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