Вот вывод:
strace -e trace=open -ff firefox 2>&1 | tail -n20
[pid 6468] open("/usr/share/sounds/freedesktop/stereo/dialog-warning.oga", O_RDONLY|O_LARGEFILE) = 28
[pid 6480] open("/proc/meminfo", O_RDONLY|O_CLOEXEC) = 29
[pid 6468] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 28
[pid 6468] open("/usr/lib/libXss.so.1", O_RDONLY|O_CLOEXEC) = 28
Process 6481 attached
[pid 6471] +++ exited with 0 +++
[pid 6479] +++ exited with 0 +++
[pid 6478] +++ exited with 0 +++
[pid 6477] +++ exited with 0 +++
[pid 6481] +++ exited with 0 +++
[pid 6470] +++ exited with 0 +++
[pid 6475] +++ exited with 0 +++
[pid 6474] +++ exited with 1 +++
[pid 6480] +++ exited with 1 +++
[pid 6476] +++ exited with 1 +++
[pid 6473] +++ exited with 1 +++
[pid 6472] +++ exited with 1 +++
[pid 6468] +++ exited with 1 +++
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=6468, si_status=1, si_utime=84, si_stime=29} ---
+++ exited with 1 +++