040-shell参数$?,$0,$#等

时间 2019-12-22

标签 shell 参数栏目 Unix 繁體版

原文原文链接

shell脚本中常常会遇到参数shell

printf "The complete list is %s\n" "$$"vim

shell自己的PID(processID)
printf "The complete list is %s\n" "$!"bash

Shell 最后运行后台Process 的PID
printf "The complete list is %s\n" "$?"code

上一次运行命令的返回值，正常为0
printf "The complete list is %s\n" "$*"ip

全部参数
printf "The complete list is %s\n" "$@"it

全部参数列表。如"$@"用「"」括起来的状况、以"$1" "$2" … "$n" 的形式输出全部参数。
printf "The complete list is %s\n" "$#"后台

添加shell参数的个数
printf "The complete list is %s\n" "$0"im

shell自己的文件名
printf "The complete list is %s\n" "$1""$2"脚本

第一个参数，第二个参数
文件

[root@cnsz142728 scripts]# vim parameter.sh
  1 #!/bin/bash
  2  printf "The complete list is %s\n" "$$"
  3  printf "The complete list is %s\n" "$!"
  4  printf "The complete list is %s\n" "$?"
  5  printf "The complete list is %s\n" "$*"
  6  printf "The complete list is %s\n" "$@"
  7  printf "The complete list is %s\n" "$#"
  8  printf "The complete list is %s\n" "$0"
  9  printf "The complete list is %s\n" "$1"
 10  printf "The complete list is %s\n" "$2"

"parameter.sh" 10L, 381C written                                                                                                                                                                                          
[root@cnsz142728 scripts]# ./parameter.sh 123 45
The complete list is 30763
The complete list is 
The complete list is 0
The complete list is 123 45
The complete list is 123
The complete list is 45
The complete list is 2
The complete list is ./parameter.sh
The complete list is 123
The complete list is 45

对照着来，就明白各个参数的含义。