#!/usr/bin/perl -w use JSON; opendir(my $dh, "/sys/class/net") or die "Couldn't open /sys/class/net: $!"; my @nics = grep { $_ !~ m/^\./ } readdir($dh); closedir($dh); my $json; foreach my $nic (@nics){ next unless ($nic =~ m/^(\w+[\.:]?(\d+)?)$/); $nic = $1; push @{$json->{data}}, { "{#IFNAME}" => $nic}; } print to_json($json) if (defined $json->{data}); exit(0);