bash-linux

Compare original and translation side by side

🇺🇸

Original

English

🇨🇳

Translation

Chinese

Bash Linux Patterns

Bash Linux 终端实用模式

Essential patterns for Bash on Linux/macOS.

适用于Linux/macOS的Bash实用模式。

1. Operator Syntax

1. 操作符语法

Chaining Commands

命令链式执行

Operator	Meaning	Example
`;`	Run sequentially	`cmd1; cmd2`
`&&`	Run if previous succeeded	`npm install && npm run dev`
`\|\|`	Run if previous failed	`npm test \|\| echo "Tests failed"`
`\|`	Pipe output	`ls \| grep ".js"`

操作符	含义	示例
`;`	按顺序执行	`cmd1; cmd2`
`&&`	前一个命令执行成功后再运行	`npm install && npm run dev`
`\|\|`	前一个命令执行失败后再运行	`npm test \|\| echo "Tests failed"`
`\|`	管道输出	`ls \| grep ".js"`

2. File Operations

2. 文件操作

Essential Commands

核心命令

Task	Command
List all	`ls -la`
Find files	`find . -name "*.js" -type f`
File content	`cat file.txt`
First N lines	`head -n 20 file.txt`
Last N lines	`tail -n 20 file.txt`
Follow log	`tail -f log.txt`
Search in files	`grep -r "pattern" --include="*.js"`
File size	`du -sh *`
Disk usage	`df -h`

任务	命令
列出所有文件	`ls -la`
查找文件	`find . -name "*.js" -type f`
查看文件内容	`cat file.txt`
查看前N行	`head -n 20 file.txt`
查看后N行	`tail -n 20 file.txt`
实时跟踪日志	`tail -f log.txt`
在文件中搜索内容	`grep -r "pattern" --include="*.js"`
查看文件大小	`du -sh *`
查看磁盘使用情况	`df -h`

3. Process Management

3. 进程管理

Task	Command
List processes	`ps aux`
Find by name	`ps aux \| grep node`
Kill by PID	`kill -9 <PID>`
Find port user	`lsof -i :3000`
Kill port	`kill -9 $(lsof -t -i :3000)`
Background	`npm run dev &`
Jobs	`jobs -l`
Bring to front	`fg %1`

任务	命令
列出所有进程	`ps aux`
按名称查找进程	`ps aux \| grep node`
通过PID杀死进程	`kill -9 <PID>`
查找端口占用者	`lsof -i :3000`
杀死端口占用进程	`kill -9 $(lsof -t -i :3000)`
后台运行命令	`npm run dev &`
查看后台任务	`jobs -l`
将后台任务调至前台	`fg %1`

4. Text Processing

4. 文本处理

Core Tools

核心工具

Tool	Purpose	Example
`grep`	Search	`grep -rn "TODO" src/`
`sed`	Replace	`sed -i 's/old/new/g' file.txt`
`awk`	Extract columns	`awk '{print $1}' file.txt`
`cut`	Cut fields	`cut -d',' -f1 data.csv`
`sort`	Sort lines	`sort -u file.txt`
`uniq`	Unique lines	`sort file.txt \| uniq -c`
`wc`	Count	`wc -l file.txt`

工具	用途	示例
`grep`	内容搜索	`grep -rn "TODO" src/`
`sed`	内容替换	`sed -i 's/old/new/g' file.txt`
`awk`	提取列	`awk '{print $1}' file.txt`
`cut`	截取字段	`cut -d',' -f1 data.csv`
`sort`	行排序	`sort -u file.txt`
`uniq`	去重行	`sort file.txt \| uniq -c`
`wc`	统计	`wc -l file.txt`

5. Environment Variables

5. 环境变量

Task	Command
View all	`env` or `printenv`
View one	`echo $PATH`
Set temporary	`export VAR="value"`
Set in script	`VAR="value" command`
Add to PATH	`export PATH="$PATH:/new/path"`

任务	命令
查看所有环境变量	`env` 或 `printenv`
查看单个环境变量	`echo $PATH`
设置临时环境变量	`export VAR="value"`
在脚本中设置环境变量	`VAR="value" command`
添加路径到PATH	`export PATH="$PATH:/new/path"`

6. Network

6. 网络操作

Task	Command
Download	`curl -O https://example.com/file`
API request	`curl -X GET https://api.example.com`
POST JSON	`curl -X POST -H "Content-Type: application/json" -d '{"key":"value"}' URL`
Check port	`nc -zv localhost 3000`
Network info	`ifconfig` or `ip addr`

任务	命令
下载文件	`curl -O https://example.com/file`
API请求	`curl -X GET https://api.example.com`
发送JSON格式POST请求	`curl -X POST -H "Content-Type: application/json" -d '{"key":"value"}' URL`
检查端口连通性	`nc -zv localhost 3000`
查看网络信息	`ifconfig` 或 `ip addr`

7. Script Template

7. 脚本模板

bash

#!/bin/bash
set -euo pipefail  # Exit on error, undefined var, pipe fail

bash

#!/bin/bash
set -euo pipefail  # Exit on error, undefined var, pipe fail

Colors (optional)

RED='\033[0;31m' GREEN='\033[0;32m' NC='\033[0m'

Script directory

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

Functions

log_info() { echo -e "${GREEN}[INFO]${NC} $1"; } log_error() { echo -e "${RED}[ERROR]${NC} $1" >&2; }

Main

main() { log_info "Starting..." # Your logic here log_info "Done!" }

main "$@"

---

main() { log_info "Starting..." # Your logic here log_info "Done!" }

main "$@"

---

8. Common Patterns

8. 常用模式

Check if command exists

检查命令是否存在

bash

if command -v node &> /dev/null; then
    echo "Node is installed"
fi

bash

if command -v node &> /dev/null; then
    echo "Node is installed"
fi

Default variable value

变量默认值

bash

NAME=${1:-"default_value"}

bash

NAME=${1:-"default_value"}

Read file line by line

逐行读取文件

bash

while IFS= read -r line; do
    echo "$line"
done < file.txt

bash

while IFS= read -r line; do
    echo "$line"
done < file.txt

Loop over files

遍历文件

bash

for file in *.js; do
    echo "Processing $file"
done

bash

for file in *.js; do
    echo "Processing $file"
done

9. Differences from PowerShell

9. 与PowerShell的差异

Task	PowerShell	Bash
List files	`Get-ChildItem`	`ls -la`
Find files	`Get-ChildItem -Recurse`	`find . -type f`
Environment	`$env:VAR`	`$VAR`
String concat	`"$a$b"`	`"$a$b"` (same)
Null check	`if ($x)`	`if [ -n "$x" ]`
Pipeline	Object-based	Text-based

任务	PowerShell	Bash
列出文件	`Get-ChildItem`	`ls -la`
查找文件	`Get-ChildItem -Recurse`	`find . -type f`
环境变量	`$env:VAR`	`$VAR`
字符串拼接	`"$a$b"`	`"$a$b"` (相同)
空值检查	`if ($x)`	`if [ -n "$x" ]`
管道	基于对象	基于文本

10. Error Handling

10. 错误处理

Set options

设置选项

bash

set -e          # Exit on error
set -u          # Exit on undefined variable
set -o pipefail # Exit on pipe failure
set -x          # Debug: print commands

bash

set -e          # Exit on error
set -u          # Exit on undefined variable
set -o pipefail # Exit on pipe failure
set -x          # Debug: print commands

Trap for cleanup

清理操作陷阱

bash

cleanup() {
    echo "Cleaning up..."
    rm -f /tmp/tempfile
}
trap cleanup EXIT

Remember: Bash is text-based. Use
&&
for success chains,
set -e
for safety, and quote your variables!

bash

cleanup() {
    echo "Cleaning up..."
    rm -f /tmp/tempfile
}
trap cleanup EXIT

注意： Bash是基于文本的工具。使用
&&
实现成功链式执行，使用
set -e
提升脚本安全性，记得给变量添加引号！