Output prefix with timestamp

output_prefix.sh

#!/usr/bin/env bash

{
  echo foo 1
  sleep 1
  echo bar 1 >&2
  echo foo 2
  sleep 1
  echo bar 2 >&2
} \
  2> >(perl -pe 'use POSIX strftime; print strftime("%Y-%m-%d %H:%M:%S", localtime) . " [ERR] "' >&2) \
  > >(perl -pe 'use POSIX strftime; print strftime("%Y-%m-%d %H:%M:%S", localtime) . " [INF] "')

output_prefix_function.sh

#!/usr/bin/env bash

# Time 
output-prefix() {
  "$@" \
    2> >(perl -pe 'use POSIX strftime; print strftime("%Y-%m-%d %H:%M:%S", localtime) . " [ERR]'"${prefix}"' "' >&2) \
    > >(perl -pe 'use POSIX strftime; print strftime("%Y-%m-%d %H:%M:%S", localtime) . " [INF]'"${prefix}"' "')
}

output-prefix ./loop.sh foo

Ha sorry must've mixed up my tests, seems ok!

@guillaume86 Timestamp fixed