Perl, using a linux command on users stored in a hash - linux

Question

Here is the code:
#!/usr/bin/perl
use warnings;
use strict;
use utf8;
my #temparray;
my $count = 0;
my #lastarray;
my $lastbash;
#Opens the file /etc/shadow and puts the users with an uid over 1000 but less that 65000 into an array.
open( my $passwd, "<", "/etc/passwd") or die "/etc/passwd failed to open.\n";
while (my $lines = <$passwd>) {
my #splitarray = split(/\:/, $lines );
if( $splitarray[2] >= 1000 && $splitarray[2] < 65000) {
$temparray[$count] =$splitarray[0];
print "$temparray[$count]\n";
$count++;
}
}
close $passwd;
foreach (#temparray) {
$lastbash = qx(last $temparray);
print "$lastbash\n";
}
What I want to do is use the built in linux command "last" on all the users stored in the #temparray. And i want the output to be like this:
user1:10
user2:22
Where 22 and 10 being the number of times they logged in. How can I achieve this ?
I have tried several different ways but I always end up with errors.

Answer 1

The following should perform the task as requested:
#!/usr/bin/perl
use warnings;
use strict;
use utf8;
my #temparray;
my $count = 0;
my #lastarray;
my $lastbash;
#Opens the file /etc/shadow and puts the users with an uid over 1000 but less that 65000 into an array.
open( my $passwd, "<", "/etc/passwd") or die "/etc/passwd failed to open.\n";
while (my $lines = <$passwd>) {
my #splitarray = split(/\:/, $lines );
if( $splitarray[2] >= 1000 && $splitarray[2] < 65000) {
$temparray[$count] =$splitarray[0];
print "$temparray[$count]\n";
$count++;
}
}
close $passwd;
foreach (#temparray) {
my #lastbash = qx(last $_); #<----Note the lines read in go to the $_ variable. Note use of my. You also read the text into array.
print $_.":".#lastbash."\n"; #<----Note the formatting. Reading #lastbash returns the number of elements.
}

Answer 2

You don't really need the $count, you could just do push #temparray, $splitarray[0].
That said, I'm not sure why you need #temparray either... You can just run the command against the users as you find them.
my $passwd = '/etc/passwd';
open( my $fh, '<', $passwd )
or die "Could not open file '$passwd' : $!";
my %counts;
# Get `last` counts and store them %counts
while ( my $line = <$fh> ) {
my ( $user, $uid ) = ( split( /:/, $line ) )[ 0, 2 ];
if ( $uid >= 1000 && $uid < 65000 ) {
my $last = () = qx{last $user};
$counts{$user} = $last
}
}
close $fh;
# Sort %counts keys by value (in descending order)
for my $user ( sort { $counts{$b} <=> $counts{$a} } keys %counts ) {
printf "%s:\t %3d\n", $user, $counts{$user};
}