Reading data from file into an array to manipulate within Perl script

Question

New to Perl. I need to figure out how to read from a file, separated by (:), into an array. Then I can manipulate the data.

Here is a sample of the file 'serverFile.txt' (Just threw in random #'s) The fields are Name : CPU Utilization: avgMemory Usage : disk free

 Server1:8:6:2225410
 Server2:75:68:64392
 Server3:95:90:12806
 Server4:14:7:1548700

I would like to figure out how to get each field into its appropriate array to then perform functions on. For instance, find the server with the least amount of free disk space.

The way I have it set up now, I do not think will work. So how do I put each element in each line into an array?

#!usr/bin/perl

use warnings;
use diagnostics;
use v5.26.1;

#Opens serverFile.txt or reports and error
open (my $fh, "<", "/root//Perl/serverFile.txt") 
    or die "System cannot find the file specified. $!";

#Prints out the details of the file format
sub header(){
    print "Server ** CPU Util% ** Avg Mem Usage ** Free Disk\n";
    print "-------------------------------------------------\n";
}

# Creates our variables
my ($name, $cpuUtil, $avgMemUsage, $diskFree);
my $count = 0;
my $totalMem = 0;
header();

# Loops through the program looking to see if CPU Utilization is greater than 90%
# If it is, it will print out the Server details
while(<$fh>) {
    # Puts the file contents into the variables
    ($name, $cpuUtil, $avgMemUsage, $diskFree) = split(":", $_);
    print "$name **  $cpuUtil% ** $avgMemUsage% ** $diskFree% ", "\n\n", if $cpuUtil > 90;
    $totalMem = $avgMemUsage + $totalMem;
    $count++;
}
print "The average memory usage for all servers is: ", $totalMem / $count. "%\n";

# Closes the file
close $fh;

Answer 1

For this use case, a hash is much better than an array.

#!/usr/bin/perl
use strict;
use feature qw{ say };
use warnings;

use List::Util qw{ min };

my %server;
while (<>) {
    chomp;
    my ($name, $cpu_utilization, $avg_memory, $disk_free)
        = split /:/;
    @{ $server{$name} }{qw{ cpu_utilization avg_memory disk_free }}
        = ($cpu_utilization, $avg_memory, $disk_free);
}

my $least_disk = min(map $server{$_}{disk_free}, keys %server);
say for grep $server{$_}{disk_free} == $least_disk, keys %server;