Bash - 比较参数＆＃34;是＆＃34;

Question

我想测试第一个参数是否是以下之一：＆＃34; ABC＆＃34;或＆＃34; DEF＆＃34;或＆＃34; GHI＆＃34;。

如果不是 - 打印使用并退出。

Answer 1

if [[ "$1" =~ ^(ABC|DEF|GHI)$ ]]; then
  echo "usage"
  exit
fi

Answer 2

这种情况在sh和bash中运行：

case "$1" in
    'ABC' | 'DEF' | 'GHI') ;;
    *) echo "usage"
       exit;;
esac

Answer 3

您可以使用带有字符串比较的普通if语句：

if [ "$1" != "ABC" -a "$1" != "DEF" -a "$1" != "GHI" ]; then
    echo "Usage: $0 ABC|DEF|GHI"
    exit 0
fi

或者：

if [ "$1" = "ABC" -o "$1" = "DEF" -o "$1" = "GHI" ]; then
    # Do something.
else
    echo "Usage: $0 ABC|DEF|GHI"
    exit 0
fi