I ran fcatch 23867. This seems to trace that PID. This process forks and execs other processes. Each time I get pretty bogus output, like: opsy. fcatch 23867 .updateForkedOffspring() .updateForkedOffspring() .updateForkedOffspring() .updateForkedOffspring() .updateForkedOffspring() .updateForkedOffspring() I assume this is a debugging printf. I also get this: 21148.21148 terminated normally ... but I don't really want this, I just want notification of SEGVs. Perhaps an option to change this would be nice. Or maybe just roll all the functionality of fcatch into ftrace.
The first issue is indeed bogus debug output. Removed: commit 91c313424052de804959314bd179a5ade351da23 Author: Mark Wielaard <mwielaard@redhat.com> Date: Mon Mar 31 11:45:51 2008 +0200 Removed debug output from ProcFollowUtil frysk-core/frysk/util/ChangeLog 2008-03-31 Mark Wielaard <mwielaard@redhat.com> * ProcFollowUtil.java (updateForkedOffspring): Remove debug output. The second issue is deliberate: frysk/util/FCatch.java // if the main thread exited print out a message that the process // terminated safely if(task.getTid() == task.getProc().getPid()){ printWriter.println(task.getProc().getPid() + "." + task.getTid() + " terminated normally"); printWriter.flush(); } I think it can be removed, or an extra option to print such informative messages. And merging fcatch with ftrace might be an interesting option indeed.