So, it appears to be well known that 'ss -lxu' has been broken on some systems and returns nothing. This is currently true on EL 7.2 though appears fixed in 7.3 beta. However, why is -u being passed to ss in the first place? We're doing: my $lines=system_capture_stdout_output("ss", "-lxu"); my @lines=split("\n", "$lines"); my @outp = grep ( /(@| )\/tmp\/.X11-unix\/X.*/, @lines); for(my $i=0;$i<@outp;$i++) { ... so we're filtering the output of ss for lines that look like unix sockets (/tmp/.X11-unix/X*), so -lx is appropriate. But why use '-u' to show UDP sockets? No X server that I know of listens on UDP and we certainly would filter it out anyway. diff --git a/x2goserver/bin/x2golistdesktops b/x2goserver/bin/x2golistdesktops index 386ed17..1cbc7ef 100755 --- a/x2goserver/bin/x2golistdesktops +++ b/x2goserver/bin/x2golistdesktops @@ -66,7 +66,7 @@ my $uname=$ENV{'USER'}; # -> so we need to tweak the PATH env var a little here... my $old_PATH=$ENV{'PATH'}; $ENV{'PATH'}="$ENV{'PATH'}:/usr/sbin:/sbin"; -my $lines=system_capture_stdout_output("ss", "-lxu"); +my $lines=system_capture_stdout_output("ss", "-lx"); $ENV{'PATH'}=$old_PATH; undef $old_PATH; See also https://bugzilla.redhat.com/show_bug.cgi?id=1371690 -- Orion Poplawski Technical Manager 303-415-9701 x222 NWRA/CoRA Division FAX: 303-415-9702 3380 Mitchell Lane orion@cora.nwra.com Boulder, CO 80301 http://www.cora.nwra.com