in reply to Re^2: Make array from field of another array
in thread Make array from field of another array

You can access only one element of the split result by using a list index.

my @new_array = map { (split /:/)[3] } @old_array;

Note that I have relied on split's default of splitting $_ when not provided with an explicit string. So the above is exactly equivalent to

my @new_array = map { (split /:/, $_)[3] } @old_array;

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Re^4: Make array from field of another array
by Saved (Beadle) on Apr 07, 2011 at 17:14 UTC
    That is it exactly, Thanx very much.
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Re^4: Make array from field of another array
by Saved (Beadle) on Apr 07, 2011 at 17:17 UTC
    That is it exactly, Thanx very much.
[reply]
Re^4: Make array from field of another array
by Saved (Beadle) on Apr 07, 2011 at 18:35 UTC
    This appears to work, thanx for your help. 
    #!/usr/bin/perl -w
#<UnusedGrp.pl> Find unused Groups in /etc/group
use strict;

my $GROUPfile="/etc/group";
my $gfpid = open(GFILE, "<$GROUPfile") or die "$GROUPfile File Not Fou
+nd: $!\n";
my $PASSWD="/etc/passwd";
my $pfpid = open(PFILE, "<$PASSWD") or die "$PASSWD File Not Found: $!
+\n";
my @PWLINES = <PFILE>;
my @GIDS = map { (split /:/)[3] } @PWLINES;

while (my $line = <GFILE>) {
   my @GRP = split(/:/, $line);
   if (length($GRP[3]) < 2){
     #print "$GRP[0]:$GRP[2] is zero length\n";
     if ( ! (grep $_ eq $GRP[2], @GIDS)) {
       print "$GRP[0]:$GRP[2] is Empty & not referenced in /etc/passwd
+\n";
     }
   }
}

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