Re: backslashes in shell commands

[kcott]

You escaped the backslash: that worked fine. What you didn't do was escape the single quotes.

#!/usr/bin/env perl

use strict;
use warnings;

my $cmd = "printf \'I\\x27ll\'";
print $cmd . "\n";
print `$cmd` ."\n";

Output:

$ pm_sh_escape.pl
printf 'I\x27ll'
I'll

Update: Escaping the single quotes was not the answer - see discussion below.

[Anonymous Monk]

Ken, running you code, I get:
./backslash.pl
printf 'I\x27ll'
I\x27ll

If it helps -- my perl version is v5.14.2 on x86_64-linux-gnu-thread-multi.

[kcott]

I have the same Perl version as you but a different O/S:

$ perl -v

This is perl 5, version 14, subversion 2 (v5.14.2) built for darwin-th
+read-multi-2level
...

$ uname -a
Darwin ganymede 11.4.2 Darwin Kernel Version 11.4.2: Thu Aug 23 16:25:
+48 PDT 2012; root:xnu-1699.32.7~1/RELEASE_X86_64 x86_64

It would appear that I gave you something of a bum steer regarding escaping the single quotes - sorry about that. Removing the two backslashes before the single quotes does not alter the outcome for me:

$ cat pm_sh_escape.pl
#!/usr/bin/env perl

use strict;
use warnings;

my $cmd = "printf 'I\\x27ll'";
print $cmd . "\n";
print `$cmd` ."\n";

$ pm_sh_escape.pl
printf 'I\x27ll'
I'll

Checking directly in the shell, I get the same result as you:

$ printf 'I\x27ll'
I'll

Unfortunately, that all adds up to an inability to reproduce your problem.