Shell脚本-清理日志

最近业务中常常需要编写一些脚本，故有此文，懒人必备～

#!/bin/bash
# 脚本名称: 清理日志
# 描述: 定时清理日志无用日志
# 版本: 1.0
# 作者: Cikaros
# 邮箱: Cikaros<at>qq.com
# 日期: 2025-07-02
# 版权: (C) 2025 Your Company. All rights reserved.
# === 配置参数 ===
# 默认配置（可被命令行参数覆盖）
keep_days=7
log_tag="cleanup_script"
log_file="/var/log/cleanup.log"

# === 函数定义 ===
check_root_privilege() {
    if [ "$EUID" -ne 0 ]; then
        log "错误：必须以 root 权限运行此脚本"
        exit 1
    fi
}

parse_arguments() {
    if [[ -n "$1" ]]; then
        if [[ "$1" =~ ^[0-9]+$ ]]; then
            keep_days="$1"
        else
            log "错误：保留天数必须为正整数"
            exit 1
        fi
    fi
}

log() {
    local message="$1"
    local timestamp=$(date '+%Y-%m-%d %H:%M:%S')
    
    # 写入日志文件
    if [[ -d "/var/log" ]]; then
        echo "[$timestamp] $message" >> "$log_file"
    fi
    
    # 写入系统日志
    logger -t "$log_tag" "消息：$message"
}

initialize_logging() {
    if [[ ! -f "$log_file" ]]; then
        touch "$log_file" 2>/dev/null || {
            log "错误：无法创建日志文件 $log_file"
            exit 1
        }
        chmod 644 "$log_file"
    fi
}

detect_distro() {
    local distro=""
    if command -v lsb_release &>/dev/null; then
        distro=$(lsb_release -is 2>/dev/null)
    elif [[ -f /etc/os-release ]]; then
        distro=$(grep ^ID= /etc/os-release | cut -d= -f2)
    else
        log "警告：无法识别操作系统发行版"
    fi
    echo "$distro"
}

cleanup_package_cache() {
    local distro="$1"
    case "$distro" in
        Ubuntu|Debian)
            log "正在清理 APT 缓存..."
            apt clean 2>/dev/null || { log "错误：APT 缓存清理失败"; return 1; }
            log "APT 缓存清理完成"
            ;;
        CentOS|Red*Hat)
            log "正在清理 YUM 缓存..."
            yum clean all 2>/dev/null || { log "错误：YUM 缓存清理失败"; return 1; }
            log "YUM 缓存清理完成"
            ;;
        *)
            log "警告：不支持的发行版，跳过包管理器缓存清理"
            return 0
            ;;
    esac
}

cleanup_old_logs() {
    local keep_days="$1"
    log "正在清理日志文件..."
    
    # 定义需要保留的关键日志文件路径
    local excluded_logs=(
        "/var/log/secure"
        "/var/log/syslog"
        "/var/log/messages"
        "/var/log/kern.log"
        "/var/log/boot.log"
    )
    
    # 构建 find 参数数组
    local args=(-type f -name "*.log" -mtime "+${keep_days}" -delete)
    for path in "${excluded_logs[@]}"; do
        args+=(-not -path "$path")
    done
    
    # 执行清理
    if find /var/log "${args[@]}" 2>/dev/null; then
        log "日志文件清理完成"
        return 0
    else
        log "错误：日志文件清理失败"
        return 1
    fi
}

# === 主程序 ===
main() {
    # 解析命令行参数
    parse_arguments "$@"

    # 权限检查
    check_root_privilege

    # 初始化日志
    initialize_logging

    # 记录开始
    log "清理脚本开始执行"

    # 检测操作系统发行版
    distro=$(detect_distro)

    # 清理包管理器缓存
    cleanup_package_cache "$distro" || exit 1

    # 清理旧日志
    cleanup_old_logs "$keep_days" || exit 1

    # 记录结束
    log "清理脚本执行完毕"

    exit 0
}

# === 执行入口 ===
main "$@"