Question

What would be an example of how I can call a shell command, say ‘ls -a‘ in a Perl script and the way to retrieve the output of the command as well?

Answer 1

How to run a shell script from a Perl program

1. Using system system($command, @arguments);

For example:

system("sh", "script.sh", "--help" );

system("sh script.sh --help");

System will execute the $command with
@arguments and return to your script when finished. You may check $!
for certain errors passed to the OS by the external application. Read
the documentation for system for the nuances of how various
invocations are slightly different.

2. Using exec

This is very similar to the use of system, but it will
terminate your script upon execution. Again, read the documentation
for exec for more.

3. Using backticks or qx//

my $output = `script.sh --option`;

my $output = qx/script.sh --option/;

The backtick operator and it’s equivalent qx//, excute the command and options inside the operator and return that commands output to STDOUT when it finishes.

There are also ways to run external applications through creative use of open, but this is advanced use; read the documentation for more.