perl - runcmd - run commands and output to console\log file

runcmd.pl

#!/usr/bin/perl

# examples:

# ./runcmd.pl -l -c "ls -lah"

# include <timestamp> and enable <verbose> mode
# ./runcmd.pl -t -l -v -c "ls -lah"

# run multiple commands with <delay> = 5
# ./runcmd.pl -v -d 5 -c "ls -lh && df -h && free -m && df -h" -l -t

use strict;
use warnings;
use 5.010;
use Getopt::Long;
use Data::Dumper;
use Time::HiRes;
use POSIX;
use IO::Handle;

my $logger;
my $verbose;
my $timestamp;
my $delay = 5;
my $command = 'ps aux';	# default command
my $logfile = strftime("%Y_%m_%d_%H_%M_%S", localtime) . "_" . $^T . ".log";

sub cmd_args
{
 GetOptions("log|l", \$logger, "delay|d=i", \$delay, "time|t", \$timestamp, "verbose|v", \$verbose, "command|c=s", \$command) or die $!;
 
 say $delay if $verbose;
}

sub now
{ 
 my ($seconds, $microseconds) = Time::HiRes::gettimeofday;
 my $dt = strftime(q/%Y:%m:%d %H:%M:%S./, localtime($seconds)) . sprintf("%06d", $microseconds);
 return $dt;
}

sub out
{
 my $fh;
 open($fh, '>>', $logfile) or die "$!";
 $fh->autoflush(1);
 say $fh now() if $timestamp;
 say $fh @_;
 close($fh); 
}

sub run
{
 my @cmd = qx/$command/; # run the command and store output
	
 out @cmd if $logger; # to FILE
	
 # to STDOUT
 
 say now() if $timestamp;
 
 say @cmd;				

 say now() if $verbose;
}

sub main
{
 for(;;) 
 { 
  run();
  sleep($delay); 
 }
}

cmd_args;

main;

exit;