Suppress attach/detach/exit status messages

-q option is used to suppress attach/detach process message. Compare following outputs:

a) Without -q option:

# strace -p 444
strace: Process 444 attached
restart_syscall(<... resuming interrupted nanosleep ...>) = 0
nanosleep({tv_sec=1, tv_nsec=0}, 0x7ffc026d31c0) = 0
nanosleep({tv_sec=1, tv_nsec=0}, 0x7ffc026d31c0) = 0
nanosleep({tv_sec=1, tv_nsec=0}, ^Cstrace: Process 444 detached
 <detached ...>

b) With -q option:

# strace -q -p 444
restart_syscall(<... resuming interrupted nanosleep ...>) = 0
nanosleep({tv_sec=1, tv_nsec=0}, 0x7ffc026d31c0) = 0
nanosleep({tv_sec=1, tv_nsec=0}, 0x7ffc026d31c0) = 0
nanosleep({tv_sec=1, tv_nsec=0}, ^C <detached ...>

-qq option will also suppress process exit status message. Compare following outputs:

a) Without -qq option:

# strace ls
......
exit_group(0)                           = ?
+++ exited with 0 +++

b) With -qq option:

# strace -qq ls
......
exit_group(0)                           = ?