We capture the output of top -SHIwz -d 2 in a debug script, but there are no processes shown. The lines for the processes are all blank. Upon investigation, this only occurs when TERM is not set in the environment. This can be easily reproduced: $ env TERM=dumb top -SHIwz -d 2 | cat Processes are listed. $ env -u TERM top -SHIwz -d 2 | cat Blank lines are displayed where processes should be listed. We are working around this issue with -n to force non-interactive mode, but it would be good to fix top since screen_width = 0 doesn't seem like it would ever be what someone actually wants. I've reproduced this on 12 13 and CURRENT.