Shell之StdI/O和Pipe

Shell之StdI/O和Pipe

😄 Written by Zak Zhu

学习python风格, 优雅规范书写shell代码

目录

• Shell之StdI/O和Pipe
  • 参考
  • StdI/O重定向
  • Pipe
  • 常用组合

参考

• RHCE培训(RH033/unit-7)
• archoncap/Linux CAT与ECHO命令详解(https://www.cnblogs.com/archoncap/p/6080088.html)

StdI/O重定向

操作	注释
>	Overwrite
1>	Redirect STDOUT to file
2>	Redirect STDERR to file
&>	Redirect all output to file
>>	Append
1>>	Append STDOUT to file
2>>	Append STDERR to file
3>>	Append all output to file
2>&1	Redirect STDERR to STDOUT
<<WORD	Redirect multiple line from keyboard to STDIN with <<WORD

Pipe

1. COMMAND1 | COMMAND2

   • send STDOUT of COMMAND1 to STDIN of COMMAND2 instead of the screen
   • STDERR is not forwarded across pipes

   

2. COMMAND1 | tee [-a] FILE | COMMAND2

   stores STDOUT of COMMAND1 in FILE, then pipes to COMMAND2

常用组合

Examples:

• echo > test

  

• find /etc/ -name passwd &> find.all

  

• find /etc/ -name passwd 2>&1 | head

  2>&1: Redirects STDERR to STDOUT

  • Useful for sending all output through a pipe

  

• (cal 12 2018 ; cal 1 2019) | head -n 12

  

• find /etc/ -name passwd &> /dev/null

• find /etc/ -name passwd > find.out 2> find.err

  

• find /etc/ -name passwd 2> /dev/null | tee find.out | head

  

• cat > test.sh << EOF