linux - 接受可选参数的 Shell 脚本

Question

这个问题已经有答案了:

How to write a bash script that takes optional input arguments? (10 个回答)

已关闭 7 年前。

如何在 shell 脚本中获取可选参数。

Command Line argument would be: ./abc.sh parm1 parm2 parm3 parm4

这里 parm3 和 parm4 是可选的，具体取决于 parm1(config)

How to write a shell script which will take mandatorily parm1 and parm2 as argument and treat the other two as optional parameters

Answer 1

对所需参数使用 ${var?} 语法:

#!/bin/sh

: ${1:?first argument is required}
: ${2:?second argument is required}

您可以使用 $# 检查参数数量，这样您就可以执行以下操作:

#!/bin/sh
die() { echo "$@" >&2; exit 1; }
case ${1?} in
foo) test $# = 4 || die When first argument is foo, you must give 4 args;;
bar) test $# = 2 || die When first argument is bar, only give 2 args;;
*) ;;
esac