Bash Retry helper that supports stabilization

retry.sh

#!/usr/bin/env bash

function _retry () (
  if [ $# -lt 1 ]; then
    echo >&2 "usage: $0 <command> [max] [min] [step] [timeout]"
    return
  fi

  cmd=$1
  max=${2:-10}
  min=${3:-1}
  step=${4:-5}
  timeout=${5:-0}

  failed=0
  succeeded=0

  set +e
  sigint=0
  trap 'sigint=1' SIGINT

  while true; do
    eval "(timeout $timeout "$cmd") >&2 &"
    child=$!
    wait "$child"
    ret=$?
    if [ "$sigint" = 1 ]; then
      kill -SIGINT "$child"
      wait "$child"
      echo
      echo "retry: warning: stopping execution because of SIGINT signal"
      return 1
    fi
    if [ "$ret" = 0 ]; then
      ((succeeded=succeeded+1))
      if [ "$succeeded" -ge "$min" ]; then
        echo >&2 "retry: success: command '$cmd' is stable"
        return 0
      else
        echo >&2 "retry: command '$cmd' succeeded, stabilizating [$succeeded/$min]"
      fi
      ((failed=0))
    else
      ((failed=failed+1))
      if [ "$failed" -ge "$max" ]; then
        echo >&2 "retry: error: command '$cmd' failed after $failed tries"
        return 1
      fi
      echo >&2 "retry: command '$cmd' failed, retrying [$failed/$max]"
      ((succeeded=0))
    fi
    sleep "$step"
    [ "$sigint" = 1 ] && return 1
  done
)