本文整理了Shell脚本中常用的自定义函数，涵盖文件操作、系统监控、网络管理、用户交互等场景，每个函数均提供详细注释，助力提升脚本开发效率。
基础文件操作
文件/目录存在性检查
1
2
3
4
5
6
7
8
9
10
11
12
13
|
file_exists() {
[ -f "$1" ] && echo "✅ File exists." || echo "❌ File does not exist."
}
dir_exists() {
[ -d "$1" ] && echo "📂 Directory exists." || echo "📂 Directory does not exist."
}
|
文件属性获取
1
2
3
4
5
6
7
8
9
10
11
12
13
|
get_file_size() {
du -sh "$1" 2>/dev/null | awk '{print $1}'
}
last_modified_file() {
ls -t "$1" 2>/dev/null | head -n 1
}
|
系统信息查询
系统状态
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
|
is_root() {
[ "$(id -u)" -eq 0 ] && echo "👑 Root user" || echo "🚫 Not root user"
}
get_ip() {
hostname -I | awk '{print $1}'
}
system_load() {
uptime | awk -F'load average:' '{print $2}' | xargs
}
|
资源监控
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
|
memory_usage() {
free | awk '/Mem/{printf("%.1f%%"), ($3/$2)*100}'
}
cpu_usage() {
top -bn1 | grep "Cpu(s)" | awk '{print $2 + $4}'
}
check_disk_space() {
threshold=${2:-80}
usage=$(df -h "$1" 2>/dev/null | awk 'NR==2{print $5}' | cut -d'%' -f1)
[ "$usage" -ge "$threshold" ] && echo "⚠️ Disk over $threshold%: $usage%" || echo "✅ OK ($usage%)"
}
|
时间与日期
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
|
current_date() {
date +"%Y-%m-%d"
}
current_time() {
date +"%H:%M:%S"
}
date_diff() {
from=$(date -d "$1" +%s)
to=$(date -d "$2" +%s)
echo $(( (to - from)/(60*60*24) ))
}
|
日志与备份和分析
1
2
3
4
5
6
7
8
9
10
|
backup_file() {
cp -v "$1" "${1}_$(date +%Y%m%d_%H%M%S).bak" 2>/dev/null
}
log_message() {
local log_file=${2:-/var/log/myapp.log}
echo "[$(date +%Y-%m-%d\ %H:%M:%S)] $1" >> "$log_file"
}
|
网络与服务管理
网络连通性
1
2
3
4
5
6
7
8
9
10
11
12
13
|
ping_check() {
ping -c 1 "$1" &> /dev/null && echo "✅ $1 reachable" || echo "❌ unreachable";
}
http_status() {
curl -s -o /dev/null -w "%{http_code}" "$1";
}
|
端口与服务
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
|
is_port_open() {
ss -tuln | grep -q ":$1\b" && echo "✅ Port $1 is open" || echo "❌ Port $1 is closed"
}
service_status() {
systemctl is-active --quiet "$1" && echo "🟢 $1 is running" || echo "🔴 $1 is stopped"
}
restart_service() {
systemctl restart "$1" && echo "🚀 Service $1 restarted" || echo "❌ Failed to restart $1"
}
|
用户交互与验证
确认提示
1
2
3
4
5
6
7
8
|
confirm() {
read -p "$1 确认(y/n) " -n 1 -r
echo
[[ $REPLY =~ ^[Yy]$ ]] || exit 1
}
|
参数验证函数
1
2
3
4
5
6
|
require_arg() {
[ $# -eq 0 ] && echo "❌ Missing argument" && exit 1
}
|
进程管理
进程操作
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
|
find_pid() {
pgrep -f "$1" || echo "PID not found"
}
kill_process() {
kill "$1" && echo "✅ Killed $1" || echo "❌ Failed"
}
|
压缩与解压
压缩函数
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
|
tar_compress() {
tar -czf "${1}.tar.gz" -C "$(dirname "$1")" "$(basename "$1")"
}
tar_decompress() {
tar -xzf "$1" -C "${2:-.}"
}
|
权限与安全
权限控制函数
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
|
set_permissions() {
chmod "${2:-755}" "$1" && echo "✅ Permissions set" || echo "❌ Failed"
}
change_owner() {
chown "${1}:${2}" "$3" && echo "✅ Ownership changed" || echo "❌ Failed"
}
|
增强功能函数
彩色输出与提示
1
2
3
4
5
6
7
8
9
10
11
|
print_color() {
local text=$1 color=$2
case $color in
red) echo -e "\033[31m$text\033[0m" ;;
green) echo -e "\033[32m$text\033[0m" ;;
yellow) echo -e "\033[33m$text\033[0m" ;;
blue) echo -e "\033[34m$text\033[0m" ;;
*) echo "$text" ;;
esac
}
|
安全与随机化
1
2
3
4
5
6
7
|
generate_random_string() {
length=${1:-10}
tr -dc 'a-zA-Z0-9' < /dev/urandom | fold -w "$length" | head -n 1
}
|
参数验证
1
2
3
4
5
6
7
8
9
10
|
command_exists() {
command -v "$1" >/dev/null 2>&1 && return 0 || return 1
}
safe_function() {
[ $# -ne 1 ] && echo "❌ Usage: $0 <arg>" && exit 1
}
|
