wait-for-file.sh

wait-for-file.sh

#!/bin/sh

# Wait for a file to exist
# Modeled off this script
# https://gist.github.com/gregberns/7e1254209860632f7a1bf9aa7c7638ee

TIMEOUT=15
QUIET=0

echoerr() {
  if [ "$QUIET" -ne 1 ]; then printf "%s\n" "$*" 1>&2; fi
}

usage() {
  exitcode="$1"
  cat << USAGE >&2
Usage:
  $cmdname filepath [-t timeout] [-- command args]
  -q | --quiet                        Do not output any status messages
  -t TIMEOUT | --timeout=timeout      Timeout in seconds, default 10s, zero for no timeout
  -- COMMAND ARGS                     Execute command with args after the test finishes
USAGE
  exit "$exitcode"
}

wait_file() {
  local file="$1"; shift
  local wait_seconds="${1:-10}"; shift # 10 seconds as default timeout

  for i in `seq $TIMEOUT` ; do
    test -e "$file" > /dev/null 2>&1
    # nc -z "$HOST" "$PORT" > /dev/null 2>&1

    result=$?
    if [ $result -eq 0 ] ; then
      if [ $# -gt 0 ] ; then
        exec "$@"
      fi
      exit 0
    fi
    sleep 1
  done
  echo "Operation timed out" >&2
  exit 1
}

while [ $# -gt 0 ]
do
  case "$1" in
    */* )
    FILE_PATH=$(printf "%s\n" "$1")
    # PORT=$(printf "%s\n" "$1"| cut -d : -f 2)
    shift 1
    ;;
    -q | --quiet)
    QUIET=1
    shift 1
    ;;
    -t)
    TIMEOUT="$2"
    if [ "$TIMEOUT" = "" ]; then break; fi
    shift 2
    ;;
    --timeout=*)
    TIMEOUT="${1#*=}"
    shift 1
    ;;
    --)
    shift
    break
    ;;
    --help)
    usage 0
    ;;
    *)
    echoerr "Unknown argument: $1"
    usage 1
    ;;
  esac
done

TIMEOUT=$TIMEOUT || -10

if [ "$FILE_PATH" = "" ]; then
  echoerr "Error: you need to provide a file path to check."
  usage 2
fi

wait_file "$FILE_PATH" "$TIMEOUT"