Add bg_killall

README.md

@@ -47,6 +47,11 @@ Run `bg_block`, then start `...cmd` in the background and add its PID to
 `$BG_PIDS`.  
 Does not start `...cmd` if `bg_block` fails.
 
+#### bg_killall([SIGNAL=TERM])
+
+Kill all running processes and wait for them to exit.  
+Always returns `0`.
+
 #### bg_block([MAX=$BG_MAX_PARALLEL])
 
 Wait until there are no more than `$MAX` running processes
@@ -123,6 +128,7 @@ bg_block 0
 #### Run a set of watchers and exit when any of them fails
 
 ```
+trap bg_killall SIGTERM SIGHUP SIGINT ERR
 BG_MAXPARALLEL=-1 BG_SIGNAL=TERM
 bg_run program --watch
 bg_run other-program --wait

bgpid.bats

@@ -101,6 +101,18 @@ export -f sleep_ret
   (($(date +%s) - start < 1)) || false
 }
 
+@test 'bg_killall kills all processes' {
+  local start
+  start=$(date +%s)
+  bash -ec "close_non_std_fds; source $BATS_TEST_DIRNAME/bgpid.sh; set -e
+  bg_run sleep_ret 3
+  bg_run sleep_ret 3
+  bg_run sleep_ret 3
+  bg_killall
+  "
+  (($(date +%s) - start < 1)) || false
+}
+
 @test 'subshell invocations do not inherit BG_PIDS' {
   bash -ec "close_non_std_fds; source $BATS_TEST_DIRNAME/bgpid.sh; set -e
   bg_run ret 1

bgpid.sh

@@ -21,6 +21,14 @@ bg_run() {
   "$@" & BG_PIDS+=($!)
 }
 
+bg_killall() {
+  [[ ${#BG_PIDS[@]} -eq 0 ]] || kill -"${1:-TERM}" "${BG_PIDS[@]}" 2>/dev/null || true
+  while [[ ${#BG_PIDS[@]} -gt 0 ]]; do
+    bg_waitany || true
+  done
+  return 0
+}
+
 # shellcheck disable=2120
 bg_block() {
   local lvl=$1