1trap 'echo USR1 $BASHPID' USR1
2trap 'echo foo $BASH_SUBSHELL' 0
3
4trap | cat
5echo between
6( trap )
7echo between 2
8{ trap; } | cat
9
10( echo in subshell: $BASH_SUBSHELL )
11( echo in subshell pipeline: $BASH_SUBSHELL ) | cat
12
13{ echo group pipeline: $BASH_SUBSHELL;
14  trap 'echo EXIT-group.$BASH_SUBSHELL' EXIT; } | cat
15