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

when I go to run the program I relize that its not getting to the second foreach loop. Any ideas? and does my code look like it will work? 
#!/usr/bin/perl -w
#mp3Finder.pl
use strict;
use File::Copy;

for(1...262)
{
   print $_;
   my $dir = "/media/second/testdisk/linux/recup_dir.$_"; 
   print $dir;
   chdir($dir);
   
   my @mp3s = glob "*.mp3";
   
   for(@mp3s) 
   {
     my $music = "/home/zack/music/$_";
     copy($_, $music);
   }
}

[download]

Replies are listed 'Best First'.
Re: Trying to find and copy mp3s
by Joost (Canon) on Feb 11, 2007 at 19:43 UTC
    well either there are no dirs named /media/second/testdisk/linux/recup_dir.1 .. /media/second/testdisk/linux/recup_dir.262, or you don't have rx permission, or there are no files in those dirs ending in .mp3, or you don't have permission to write to /home/zack/music. this is why you should check if system calls succeed.

    try 

    chdir($dir) or die "Can't chdir to $dir: $!";

    [download]
    and 
    copy($_,$music) or die "Can't copy $_ to $music: $!";

    [download]
    "What should it profit a man, if he should win a flame war, yet lose his cool?"
[reply]
[d/l]
[select]
Re: Trying to find and copy mp3s
by kyle (Abbot) on Feb 11, 2007 at 21:56 UTC

    It's a bad idea to use $_ for two loops at once. I don't think that's what your problem is here, but it could become a maintainability problem later.

    You should check that chdir and copy succeeded before charging ahead in your loop (as already suggested by Joost).

    It's always a good idea to use warnings too (though, again, I don't think that will help in this case). [Oops, as esper points out, the OP already has -w.] 

    #!/usr/bin/perl -w
#mp3Finder.pl
use strict;
use warnings;
use File::Copy;

foreach my $dirnum (1 .. 262)
{
   print $dirnum;
   my $dir = "/media/second/testdisk/linux/recup_dir.$dirnum"; 
   print $dir;
   chdir($dir) or die "Can't chdir($dir): $!";
   
   my @mp3s = glob "*.mp3";
   
   foreach my $mp3 (@mp3s) 
   {
     my $music = "/home/zack/music/$mp3";
     copy($mp3, $music) or die "Can't copy $mp3 to $music: $!";
   }
}

    [download]
[reply]
[d/l]
[select]
      Its definately getting to the loops and everything, but now I get an error on the copy cammand, saying that the file I'm copying to does not exist. How can I create it?
[reply]

        It's probably telling you that because the destination directory does not exist. You can create it with mkdir. For example: 

        my $destination = "/home/zack/music";
my $music = "$destination/$mp3";
if ( ! -d $destination && ! mkdir $destination ) {
    die "Can't mkdir $destination: $!";
}
copy( $mp3, $music ) or die "Can't copy $mp3 to $music: $!";

        [download]
[reply]
[d/l]
      This is the second time in recent days that I have seen use warnings suggested to someone whose code already included #!/usr/bin/perl -w. I have long been under the impression that the -w switch is equivalent to use warnings. (man perlrun states that -w "prints warnings about dubious constructs" and "really just enables the internal $^W variable", but does not explictly describe its relation to use warnings.)

      Is there an actual, functional difference between the two? If not, why the suggestion that both should be used?

[reply]
[d/l]
[select]
[reply]

        I don't know of any functional difference. I just didn't notice the -w in the OP. In my own code, I always have both: 

        use strict;
use warnings;

        [download]
        ...just like that at the top of every file. It's such a strong habit that when I see just one of them, I think the other is missing.

        Anyway, my mistake. Thanks for pointing it out.

[reply]
[d/l]
[select]
[reply]

Back to Seekers of Perl Wisdom