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Retry With Exponential Backoff

Retry a shell command with exponential backoff and a bounded attempt count, failing loudly when exhausted.

BashResilience

Code

snippet
#!/usr/bin/env bash
set -euo pipefail

retry() {
  local max_attempts="$1"; shift
  local delay=1
  local attempt=0
  until "$@"; do
    attempt=$((attempt + 1))
    if (( attempt >= max_attempts )); then
      echo "retry: giving up after ${attempt} attempts" >&2
      return 1
    fi
    echo "retry: attempt ${attempt} failed, sleeping ${delay}s" >&2
    sleep "$delay"
    delay=$((delay * 2))
  done
}

# 用法示例：最多 5 次，命令失败时按 1s、2s、4s、8s 退避
retry 5 curl -fsS --max-time 10 https://api.example.com/health

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