linux - Comparing and displaying hash values -

i able print of lines /etc/passwd uid , username.

i compare values of uid , display corresponding usernames <150 , >150.

this while loop , count

while(<passwd>){     chomp;     @f = split /:/;     sort @f;     @{$passwd{$f[3]}}=@f;     print @f[3 , 0], "\n"; }  $count = keys(%passwd); print $count, "\n"; 

sort @f nothing - sort returns list sorted, not change in place. if added use warnings; programme, perl tell you.

this how it:

#!/usr/bin/perl use warnings; use strict;  open $passwd, '<', '/etc/passwd' or die $!;  %passwd; while (<$passwd>) {     chomp;     @f = split /:/;     @{ $passwd{ $f[3] } } = @f;  }  $reported = 0; $k (sort { $a <=> $b } keys %passwd) {     if ($k > 150 , not $reported) {         $reported = print "over 150\n";     }     print "$k\n"; } 

you can grep keys small ones:

my @under150 = grep $_ < 150, keys %passwd; print $_->[0], "\n" @passwd{ @under150 };