rerun

#!/usr/bin/env bash 

usage() {
  printf '%s\n' "Usage: rerun [-h] CMD PATTERN
rerun detects close_write events in the current directory for files matching
the supplied PATTERN and executes the specified shell CMD whenever one is
detected.

where:
  -h, --help  - show this help text
  CMD         - the shell command to run 
  PATTERN     - regex identifying files to watch"
}

main() {
  inotifywait -e close_write -m . |
  while read -r directory events filename; do
    if [[ "${filename}" =~ ${PATTERN} ]] ; then 
      echo "${events}: ${filename}"
      bash -c "${CMD}"
    fi
  done

}

# Option parsing
declare PARAMS=""
declare CMD
declare PATTERN
while (( "$#" )); do
  case $1 in
    -h|--help)  # display help message
      usage
      exit 1
      ;;
    --)  # End argument parsing
      shift
      break
      ;;
    -*|--*)  # unsupported flags
      echo "Unsupported flag: $1" >&2
      usage
      exit 1
      ;;
    *)  # preserve positional arguments
      PARAMS="${PARAMS} $1"
      shift
      ;;
  esac
done

# set positional arguments in their proper place
eval set -- "${PARAMS}"

# parse positional args
CMD="$1"
PATTERN="$2"

# Freeze configuration flags
readonly CMD PATTERN

main