=== Expected behavior:

$ time ./timeout -v -s TERM 2 sh -T -c 'sleep 5 & sleep 5; echo ok; date'
timeout: time limit reached or received SIGALRM
timeout: sending signal TERM(15) to command 'sh'
timeout: signaled 3 processes
timeout: sending signal CONT(19) to command 'sh'
timeout: collected zombie: pid=1134, exit=0, signal=15
timeout: collected zombie: pid=1135, exit=0, signal=15
timeout: child terminated: pid=1133, exit=0, signal=15

real	0m2.088s  <--
user	0m0.000s
sys	0m0.018s

=== Strange with SIGINT and SIGQUIT:

$ time ./timeout -v -s INT 2 sh -T -c 'sleep 5 & sleep 5; echo ok; date'
timeout: time limit reached or received SIGALRM
timeout: sending signal INT(2) to command 'sh'
timeout: signaled 3 processes
timeout: sending signal CONT(19) to command 'sh'
timeout: child terminated: pid=989, exit=0, signal=2
  <-- blocking here
timeout: collected zombie: pid=990, exit=0, signal=0

real	0m5.009s  <--
user	0m0.000s
sys	0m0.009s

=== Another example (Ctrl-C cannot kill the command):

$ time ./timeout -v -s INT 2 sh -T -c 'sleep 5 & sleep 5; echo ok; date'
^Ctimeout: received terminating signal INT(2)
timeout: sending signal INT(2) to command 'sh'
timeout: signaled 3 processes
timeout: sending signal CONT(19) to command 'sh'
timeout: child terminated: pid=1762, exit=0, signal=2
timeout: time limit reached or received SIGALRM
timeout: sending signal INT(2) to command 'sh'
timeout: signaled 1 processes
timeout: sending signal CONT(19) to command 'sh'
^Ctimeout: received terminating signal INT(2)
timeout: sending signal INT(2) to command 'sh'
timeout: signaled 1 processes
timeout: sending signal CONT(19) to command 'sh'
^Ctimeout: received terminating signal INT(2)
timeout: sending signal INT(2) to command 'sh'
timeout: signaled 1 processes
timeout: sending signal CONT(19) to command 'sh'
timeout: collected zombie: pid=1763, exit=0, signal=0

real	0m5.011s
user	0m0.000s
sys	0m0.008s

---------------------------------------------------------------------------

Ran 'pstree $(pgrep timeout)' and it showed the background sleep process
was reparented to the timeout(1) utility, for example:

$ while true; do if pgrep timeout; then date; pstree $(pgrep timeout); fi; sleep 1; done
1398
Tue Mar 11 18:02:09 CST 2025
-+= 01398 aly ./timeout -v -s TERM 3 sh -T -c sleep 5 & sleep 5; echo ok; date
 \-+- 01399 aly sh -T -c sleep 5 & sleep 5; echo ok; date
   |--- 01400 aly sleep 5
   \--- 01401 aly sleep 5
1398
Tue Mar 11 18:02:10 CST 2025
-+= 01398 aly ./timeout -v -s TERM 3 sh -T -c sleep 5 & sleep 5; echo ok; date
 \--- 01400 aly sleep 5
1398
Tue Mar 11 18:02:11 CST 2025
-+= 01398 aly ./timeout -v -s TERM 3 sh -T -c sleep 5 & sleep 5; echo ok; date
 \--- 01400 aly sleep 5
^C

---------------------------------------------------------------------------

My timeout(1) working branch:
https://gitweb.dragonflybsd.org/~aly/dragonfly.git/shortlog/refs/heads/posix-timers