Bash notebook for nifty things

notebook.sh

#!/usr/bin/env bash

# wait for backgrounded jobs and propagate $?>0.
local pid
while read -r pid; do wait "$pid"; done < <(jobs -p)

# wait for backgrounded jobs, propagate $?>0, and exit early on failure.
while (($(jobs -p | wc -l) > 0)); do
  if wait -n; then
    :
  else
    ret=$?
    jobs -p | xargs -n1 kill 2>/dev/null
    wait
    exit $ret
  fi
done

# Benchmark call() in ms
_THEN=$(date +%s.%N)
call()
printf "fn(): %ss\n" "$(echo "($(date +%s.%N) - $_THEN)" | bc)" >&2

# Output a stacktrace (https://stackoverflow.com/a/62757929/339505)
stacktrace() {
   local level=1 line file func linetxt
   while read -r line func file < <(caller $level); do
      linetxt=$(sed -n "${line}p" "${file}" | sed 's/ *//')
      linetxt=${linetxt# *}
      printf "[%d] %s:%d %s(): %s\n" "$level" "${file#$PWD/}" "$line" "$func" "$linetxt"
      ((level++))
   done
}

# Get relative timings of all lines in a script
bash -x script.sh 2>&1 | ts -i %.s

# Parallelize work and append results to array (https://stackoverflow.com/a/64783182/339505)
readarray -td $'\0' -O"${#results[@]}" build_env < <(
   while IFS= read -r target <&3; do (
     do_work
     printf "\0"
   ) & done 3< <(get_work)
   while read -r pid; do wait "$pid"; done < <(jobs -p)
)