execute command line command from Perl?

Question

HI all,

i need to have this command line command executed from a Perl file:

for file in *.jpg ; do mv $file `echo $file | sed 's/\(.*\.\)jpg/\1jp4/'` ; done

So I added the folders and tried:

system "bash -c 'for file in $mov0to/*.jp4 ; do mv $file `echo $basedir/internal/0/$file | sed 's/\(.*\.\)jp4/\1jpg/'` ; done'";

But all I get is:

sh: Syntax error: "(" unexpected
No file specified

I am on Kubuntu 10.4

Thanks, Jan

You're shelling out to run a for loop and call sed and mv? The Perl gods feel insulted and will now smite you and your children, until you rewrite your script to do this all in Perl. — Ether
– Ether, Commented Nov 5, 2010 at 0:23

Leolo · Accepted Answer · 2010-11-05 09:11:29Z

4

I can think of many better ways of doing this, but ideally you want pure Perl:

use File::Copy qw( move );
opendir DIR, $mov0to or die "Unable to open $mov0to: $!";
foreach my $file ( readdir DIR ) {
    my $out = $file;
    next unless $out =~ s/\.jp4$/.jpg/;
    move "$mov0to/$file", "$basedir/internal/0/$out" or die "Unable to move $mov0to/$file->$basedir/internal/0/$out: $!";
}
closedir DIR;

If you insist on doing the lifting in Bash, you should be doing:

system qq(bash -c 'for file in $mov0to/*.jp4 ; do mv \$file $basedir/internal/0/\${file\/%.jp4\/.jpg} ; done');

answered Nov 5, 2010 at 9:11

Leolo

1,3379 silver badges14 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

mu is too short · Accepted Answer · 2010-11-05 00:24:50Z

1

All of the variables inside the double quotes will get interpolated, the $file that you're using in the bash for loop in particular. We don't have enough context to know where the other variables ($mov0to and $basedir) come from or what they contain so they might be having the same problems. The double quotes are also eating your backslashes in the sed part.

Andy White is right, you'd have less of a mess if the bash commands were in a separate script.

answered Nov 5, 2010 at 0:24

mu is too short

436k71 gold badges863 silver badges822 bronze badges

Comments

Andy White · Accepted Answer · 2010-11-05 00:12:53Z

0

It's most likely a problem with nested quotes. I would recommend either moving that bash command into its own (bash) script file, or writing the loop/logic directly in Perl code, making simpler system calls if you need to.

answered Nov 5, 2010 at 0:12

Andy White

88.7k48 gold badges178 silver badges212 bronze badges

Collectives™ on Stack Overflow

execute command line command from Perl?

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related