I Need A Shell Script, Or A C Program....

Fine, I'll make it more points...if that'll make people happier; I'd do it myself if I knew how to program.

#!/usr/local/bin/perl

use warnings;
use File::Find ();

$cols = 3;
$linewidth = 80;      # Columns on terminal
$lines = 24;            # Lines on terminal

$| = 1;

# Get a list of users:
@users = ();
setpwent();
while ($user = getpwent()) {
  push(@users, $user);
}
endpwent();

$width = int($linewidth/$cols) - 4;

$col = 0;
$line = 0;
foreach $i (1..@users) {
  printf "%3i %-${width}s", $i, $users[$i-1];
  $col = ($col + 1) % $cols;
  if (!$col) {
    print "\n";
    $line = ($line + 1) % ($lines - 1);
    if (!$line) {
      print "Press RETURN to continue...";
      $ans = <STDIN>;
    }
  }
}
print "\n" if ($col);
print "Enter user number or userid? ";
chomp($user = <STDIN>);
$user = $users[$user] if ($user =~ /^\d+$/);

$dir = (getpwnam($user))[7];

die "Invalid user $user\n" unless (defined($dir));

chdir($dir) or die "Can't chdir `$dir': $!\n";

@mp3 = ();
$line = 0;

File::Find::find({wanted => \&wanted}, '.');

$n = @mp3;
if ($n == 0) {
  print "No mp3 files found\n";
  exit(0);
} elsif ($n == 1) {
  print "Delete this file (y/n)? ";
} else {
  print "Delete these $n files (y/n)? ";
}
chomp($ans = <STDIN>);

if ($ans =~ /^y/i) {
  $done = unlink(@mp3);
  print "$done file(s) deleted\n";
}


sub wanted {
    if (/^.*\.mp3\z/is) {
      push(@mp3, $File::Find::name);
      print("$File::Find::name\n");
      $line = ($line + 1) % ($lines - 1);
      if (!$line) {
        print "Press RETURN to continue...";
        $ans = <STDIN>;
      }
    }
}

here is my version:

#!/usr/bin/perl -w
#
# This program searches for mp3's and in a draconing way, zaps them.
#
# William Julien
####

use strict;
use File::Find;

#
# put perl into interactive mode
#
BEGIN {
    $| = 0;
}

#
# declare our variables
#
my ($userid,    # userid
    $uid,       # numerid uid
    $username,  # user name
    $prompt,    # prompt variable
    $gecos,     # contents of the gecos field
    %userdata,  # user information
    @list,      # list of all mp3 files
    %filelist   # list of mp3 files for a user
    );


#
# get the directory by parameter or default to /home
#
@ARGV or push @ARGV, '/home';

#
# first get a list of userid's and user names on the system
#
open PASSWD, "/etc/passwd";
while (<PASSWD>) {
    ($userid, $uid, $gecos) = (split /:/)[0,2,4];
    $username = (split /,/,$gecos)[0];
    $userdata{$uid} = [ $userid, $username ];
}
close PASSWD;

#
# find all the mp3s
#
find (\&wanted, @ARGV);

#
# associate each filename with a user
#
foreach (@::list) {
    $uid = (stat("$_"))[4];
    if ( $uid > 0 ) {
        push @{$filelist{$uid}}, $_;
    }
}

#
# prompt for a uid
#
while(1) {
    #
    # display a list of userid's with mp3s
    #
    if ( scalar keys %filelist > 0 ) {
        print "The following user(s) have mp3 files\n\n";
        printf "%6s %8s %s\n", "uid","userid","username";
        foreach $uid ( keys %filelist ) {
            printf "%6d %8s %s\n", $uid,
                                 ${userdata{$uid}}[0],
                                 ${userdata{$uid}}[1];
        }
    } else {
        print "No users have mp3 files\n";
        exit;
    }
    print "\nEnter the uid to see the list of files (0 to exit)-> ";
    $prompt = <STDIN>;
    chomp($prompt);
    $uid = $prompt;
    if ( $prompt eq "0" ) {
        print "Done\n";
        exit;
    }
    if ( defined $filelist{$uid} ) {
        foreach (@{$filelist{$uid}}) {
            print "$_\n";
        }
        print "\nWould you like to zap them? (yes or no) -> ";
        $prompt = <STDIN>;
        chomp($prompt);
        if ( $prompt eq "yes" ) {
            foreach (@{$filelist{$uid}}) {
                print "Zapping $_\n";
                unlink $_;
            }
            delete $filelist{$uid};
        } else {
            print "Ok... The files are not zapped\n";
        }
    } else {
        print "Sorry, not a valid uid\n";
    }
}

# fin
###

#
# subroutine to find mp3 files
#
sub wanted {
    my $uid;

    if ( /mp3$/ ) {
        push @::list, $File::Find::name;
    }
}

Some comments on moonbeam's version:

(1) Reading the passwd file for userids
won't find all the users if you are using NIS or similar

(2) My version finds MP3's as well as mp3's :-)

Comments on martin's version:

your version doesn't actually find users that have mp3 files (it lists all users) and fails to work for those that do.

Did you test it?

-->touch junk.mp3
-->./martin.pl
  1 root                    2 bin                     3 daemon                
  4 adm                     5 lp                      6 sync                  
  7 shutdown                8 halt                    9 mail                  
 10 news                   11 uucp                   12 operator              
 13 games                  14 ftp                    15 gdm                  
 16 nobody                 17 moonbeam               18 informix              
 19 oracle                 20 mandoman               21 backup                
Enter user number or userid? 17
Can't opendir(.): Permission denied
No mp3 files found
-->ls -l *mp3
-rw-r-----   1 moonbeam kittens         0 Sep 18 11:45 junk.mp3

Regarding your comments.

1. true, but easily fixed by opening a process to a niscat passwd instead of the /etc/passwd.

open(PASSWD, "niscat passwd|");

2. true. I missed the "\i". change ...

if(/mp3$/) to if(/mp3$/i)

I read this part of the question:

"lists each user with a number before their username, which then the program will let me choose which user by number (or name), list all the MP3s that the user has"

as implying that CyberMage wanted to restrict the search to a particular user.

he he... Read this part of the problem.

"search all the users who have MP3s, list there usernames"

ps.. I assumed that CyberMage would want to restrict the search to a particular user, which is why I coded...

@ARGV or push @ARGV, '/home';
....
find (\&wanted, @ARGV);

The trouble with your routine is that for all the user's listed, which one has the targeted files? Imagine a system with 500 or more or so userids. It would take all afternoon to try them all... one at a time. Very tedious. I say, let the computer do the work.

By the way, I posted to linux/General an updated version with a simplified user interface. It works like this:

-->touch fred.mP3
-->zap_mp3.pl $HOME
The following user(s) have mp3 files

   uid   userid username
   502 moonbeam William Julien

Enter the uid to see the list of files (0 to exit)-> 502
/home/moonbeam/fred.mP3

Would you like to zap them? (yes or no) -> yes
Zapping /home/moonbeam/fred.mP3
No users have mp3 files

Here is the source.

#!/usr/bin/perl -w
#
# This program searches for mp3's and in a draconing way, zaps them.
#
# William Julien
####

use strict;
use File::Find;

#
# declare our variables
#
my ($userid,    # userid
    $uid,       # numerid uid
    $username,  # user name
    $prompt,    # prompt variable
    $gecos,     # contents of the gecos field
    %userdata,  # user information
    @list,      # list of all mp3 files
    %filelist   # list of mp3 files for a user
    );


#
# get the directory by parameter or default to /home
#
@ARGV or push @ARGV, '/home';

#
# first get a list of userid's and user names on the system
#
open PASSWD, "/etc/passwd";
while (<PASSWD>) {
    ($userid, $uid, $gecos) = (split /:/)[0,2,4];
    $username = (split /,/,$gecos)[0];
    $userdata{$uid} = [ $userid, $username ];
}
close PASSWD;

#
# find all the mp3s
#
find (\&wanted, @ARGV);

#
# associate each filename with a user
#
foreach (@::list) {
    $uid = (stat)[4];
    if ( $uid > 0 ) {
        push @{$filelist{$uid}}, $_;
    }
}

#
# prompt for a uid
#
while(1) {
    #
    # display a list of userid's with mp3s
    #
    if ( scalar keys %filelist > 0 ) {
        print "The following user(s) have mp3 files\n\n";
        printf "%6s %8s %s\n", "uid","userid","username";
        foreach $uid ( keys %filelist ) {
            printf "%6d %8s %s\n", $uid,
                                 ${userdata{$uid}}[0],
                                 ${userdata{$uid}}[1];
        }
    } else {
        print "No users have mp3 files\n";
        exit;
    }
    print "\nEnter the uid to see the list of files (0 to exit)-> ";
    $prompt = <STDIN>;
    chomp($prompt);
    $uid = $prompt;
    if ( $prompt eq "0" ) {
        print "Done\n";
        exit;
    }
    if ( defined $filelist{$uid} ) {
        foreach (@{$filelist{$uid}}) {
            print "$_\n";
        }
        print "\nWould you like to zap them? (yes or no) -> ";
        $prompt = <STDIN>;
        chomp($prompt);
        if ( $prompt eq "yes" ) {
            foreach (@{$filelist{$uid}}) {
                print "Zapping $_\n";
                unlink $_;
            }
            delete $filelist{$uid};
        } else {
            print "Ok... The files are not zapped\n";
        }
    } else {
        print "Sorry, not a valid uid\n";
    }
}

# fin
###

#
# subroutine to find mp3 files
#
sub wanted {
    my $uid;

    if ( /mp3$/i ) {
        push @::list, $File::Find::name;
    }
}

Well, if you really want to search first, here is another version
of my program:

#!/usr/local/bin/perl
# Usage: listmp3 [dir...]

use warnings;
use File::Find ();

$searchdir = "/home";
push(@ARGV, $searchdir) unless (@ARGV);

$cols = 3;
$linewidth = 80;      # Columns on terminal
$lines = 24;            # Lines on terminal

$| = 1;

# Find all mp3 files and record under their owners:
%mp3 = ();
File::Find::find({wanted => \&wanted}, @ARGV);


for (;;) {

  # Convert UIDs to usernames:
  @users = ();
  %uid = ();
  foreach $uid (keys %mp3) {
    push(@users, scalar(getpwuid($uid)));
    $uid{getpwuid($uid)} = $uid;
  }

  if (!@users) {
    print "No more mp3 files.\n";
    last;
  }

  $width = int($linewidth/$cols) - 4;
 
  $col = 0;
  $line = 0;
  foreach $i (1..@users) {
    printf "%3i %-${width}s", $i, $users[$i-1];
    $col = ($col + 1) % $cols;
    if (!$col) {
      print "\n";
      $line = ($line + 1) % ($lines - 1);
      if (!$line) {
        print "Press RETURN to continue...";
        $ans = <STDIN>;
      }
    }
  }
  print "\n" if ($col);
  print "Enter user number or username (press RETURN to exit)? ";
  chomp($user = <STDIN>);
  last if ($user =~ /^\s*$/);
  $user = $users[$user-1] if ($user =~ /^\d+$/);
  $uid = $uid{$user};
  next unless defined($uid);
 
  $line = 0;
  foreach $file (@{$mp3{$uid}}) {
    print "$file\n";
    $line  = ($line + 1) % ($lines - 1);
    if (!$line) {
      print "Press RETURN to continue...";
      $ans = <STDIN>;
    }
  }
  $n = @{$mp3{$uid}};
  if ($n == 1) {
    print "Delete this file (y/n)? ";
  } else {
    print "Delete these $n files (y/n)? ";
  }
  chomp($ans = <STDIN>);
 
  if ($ans =~ /^y/i) {
    $done = unlink(@{$mp3{$uid}});
    print "$done file(s) deleted\n";
    delete $mp3{$uid};
  }
}


sub wanted {
  if (/^.*\.mp3\z/is) {
    $owner = (stat($File::Find::name))[4];
    push(@{$mp3{$owner}}, $File::Find::name);
  }
}

Better. I have a few suggestions.

1. warnings.pm does not exist in perl prior to 5.6. It is better to just use the '-w' switch.

2. When you want to write production quality code, use should use the strict pragma. Particularly if this is to be run by root.

3. Now that you have a hash of the uid's after the find, why to you re-associate the uid->username map over, and over in your for loop. It would be better to do that once.

4. still doesn't work right. (I commented out the "use warnings, since this computer does not have 5.6, and added -w)

-->touch fred.mp3 tom.mp3 src/junk.mp3
-->listmp3.pl .
Use of uninitialized value at ./fred.pl line 87.
Use of uninitialized value at ./fred.pl line 87.
Argument "" isn't numeric in gpwuid at ./fred.pl line 26.
  1 root                    2 julien                
Enter user number or username (press RETURN to exit)?

moonbeam: I think you should upgrade
to the latest version of perl.
Especially for code which is to be run by root :-)

I am not rejecting any of your answers, I am just keeping this question open, so that you can resolve the minor bugs in your programs; and then tell me which one is better by leaving it as an answer...then I can run it and then accept it as an answer.

CyberMage: do you want my version
hacked to work with old versions
of perl, or do you have perl 5.6.0?

If you want "use strict" then change
the first few lines to:

use warnings;
use strict;
use File::Find ();

my ($searchdir, $cols, $linewidth, $lines, %mp3, @users, %uid,
    $col, $line, $ans, $user, $uid, $n, $done, $owner,
    $width, $i, $file);

$searchdir = "/home";



You shouldn't worry about reassociating
the uid->users map each time round
the main loop: this is very fast
compared with the time required
to print the list to the screen!

I am not sure which version of PERL it is, but I'd like to have backwards-compatible until I find out if it is 5.6 we are running.

Martin,
I'm glad you found your bug!

CyberMage,
I can't remember when the File::find module was incorporated into the standard release. If you do find yourself running on a really old version of perl, your admins can install the File::Find module from CPAN and my code will still work, unchanged.

I can rename the programs respectively to:

mp3search1.pl

mp3search2.pl

Without hurting the programs...is this correct?

you can name the program by any name you like. Even the ".pl" at the end is optional. (of course, you don't want to name it the same as some existing program)

Have you completed your evaluation?

Which script did you find best fit your needs?

It sadens me by your non-response. Both my self and martin have spent several hours responding quickly to your urgent requests for help. But, for this, we get no reward or response for our caring to your needs or respect for our efforts.

By your lack of response, I will assume this question has been resolved. Please let me know if I can be of any more assistance.

Found a different way to find a delete the MP3s from the system.