Perl backticks not capturing output <p>I have the following program snippet</p> <pre><code>my $nfdump_command = "nfdump -M /data/nfsen/profiles-data/live/upstream1 -T -R ${syear}/${smonth}/${sday}/nfcapd.${syear}${smonth}${sday}0000:${eyear}/${emonth}/${eday}/nfcapd.${eyear}${emonth}${eday}2355 -n 100 -s ip/bytes -N -o csv -q | awk 'BEGIN { FS = \",\" } ; { if (NR &gt; 1) print \$5, \$10 }'"; syslog("info", $nfdump_command); my %args; Nfcomm::socket_send_ok ($socket, \%args); my @nfdump_output = `$nfdump_command`; my %domain_name_to_bytes; my %domain_name_to_ip_addresses; syslog("info", Dumper(\@nfdump_output)); foreach my $a_line (@nfdump_output) { syslog("info", "LINE: " . $a_line); } </code></pre> <p>Bug: @nfdump_output is empty. <img src="https://i.stack.imgur.com/WSbkK.png" alt="enter image description here"></p> <p>The $nfdump_command is correct and it printing output when ran individually</p> <p><img src="https://i.stack.imgur.com/nZNZ4.png" alt="enter image description here"></p>