my @elf_files = system("ls"); #or backtiks

##</code><code>##

use strict;
use warnings;

##</code><code>##

Use of uninitialized value in concatenation (.) or string at ./derp.pl line 8.
readelf: Warning: Nothing to do.

##</code><code>##

readelf: Warning: Nothing to do.

##</code><code>##

readelf: Error: 'ffmpeg_sources' is not an ordinary file