The built in system function can be used to get the return code of a command.

#!/usr/bin/perl
use strict;
use warnings;
system("/usr/bin/hostname");   

In this example, the output of the /usr/bin/hostname command (on a Linux system) will be printed to the console

~]$ perl example.pl
server1.example.com

Often, system is used to get the return code of the command. In this example, the return code of the /usr/bin/hostname command is stored in a variable named $return_code. Printing the $return_code variable shows that the return code is 0 (success).

#!/usr/bin/perl
use strict;
use warnings;
my $return_code = system("/usr/bin/hostname");
print "$return_code \n";       

Let's say you have some bogus command.

#!/usr/bin/perl
use strict;
use warnings;
my $return_code = system("/usr/bin/bogus");
print "$return_code \n";       

The return code is -1 (failed).

Can't exec "/usr/bin/bogus": No such file or directory at testing.pl line 25.
-1