检查作为输入提供给 shell 脚本的可变数量的位置参数的有效性

Question

为了为多个平台编译一组应用程序，需要设置某些构建导出。

示例命令如下：

source exports_file.sh <plaforms> <feature1> <feature2> <feature3>

这里的位置参数<platform>是强制性的，而其他参数如<feature1>, <feature2>, <feature3>是可选的。只有在构建中需要相应的功能时才必须启用这些功能。

有效的命令行选项集是：

source exports_file.sh <plaforms> <feature1> <feature2> <feature3> source exports_file.sh <plaforms> <feature1> <feature2> source exports_file.sh <plaforms> <feature1> source exports_file.sh <plaforms>

需要注意的重要一点是脚本应该 return 在以下情况下出错：

1) <platform> 用户未提供输入参数。

2) <platform> 输入参数的值不在列表中，即它不是 1234、1235 或 1236。

3) 除了 <feature1>, <feature2>, <feature3> 之外的任何其他特征都作为输入提供。

我编写了一个运行良好的脚本，但我不确定它是否正确检查了所有输入参数的有效性。

   $> cat exports_file.sh


    if [ $# -gt 0 ]; then

    platform=

    # Common exports
    unset PLATFORM
    unset ENABLE_FEATURE_1
    unset ENABLE_FEATURE_2
    unset ENABLE_FEATURE_3

    echo "INFO: Setting common exports for $platform"
    if [ $platform == "1234" ]
    then
        export PLATFORM=91234

    elif [ $platform == "1235" ]
    then
        export PLATFORM=91235

    elif [ $platform == "1236" ]
    then
        export PLATFORM=91236

    else
        echo "ERROR: Exports are not defined for $platform."
        exit 1
    fi

    # Check for feature based exports <feature1> <feature2> <feature3>
    for var in "$@"
    do
        if [ $var == "arg2" ]
        then
            export ENABLE_FEATURE_1=Y

        elif [ $var == "arg3" ]
        then
            export ENABLE_FEATURE_2=Y

        elif [ $var == "arg4" ]
        then
            export ENABLE_FEATURE_3=Y
        else
            echo "ERROR: unrecognised argument '$var'";
            exit 1
        fi
    done
else
    echo "ERROR: No inputs parameters provided to the scripts."
    echo "Usage: source exports_file.sh <plaforms> <feature1> <feature2> <feature3>"
fi`

有没有更好的方法来编写这个脚本。最重要的是确保所有输入参数的有效性。

Answer 1

  if [ $# -gt 0 ]; then

    platform=

    # Common exports
    unset PLATFORM
    unset ENABLE_FEATURE_1
    unset ENABLE_FEATURE_2
    unset ENABLE_FEATURE_3
    echo  input parameter: $@

    echo "INFO: Setting common exports for $platform"
    if [ $platform == "1234" ]
    then
        export PLATFORM=91234
        export ENABLE_FEATURE_1=Y
        # Result
        echo $PLATFORM
        echo $ENABLE_FEATURE_1

    elif [ $platform == "1235" ]
    then
        export PLATFORM=91235
        export ENABLE_FEATURE_2=Y
        # Result
        echo $PLATFORM
        echo $ENABLE_FEATURE_2

    elif [ $platform == "1236" ]
    then
        export PLATFORM=91236
        export ENABLE_FEATURE_3=Y
        # Result
        echo $PLATFORM
        echo $ENABLE_FEATURE_3

    else
       echo "ERROR: Exports are not defined for $platform."
        exit 1
    fi
    fi

    # Check for feature based exports <feature1> <feature2> <feature3>
    #for var in "$@"
    #do
        #if [ $var == "arg2" ]
        #then
            #export ENABLE_FEATURE_1=Y

        #elif [ $var == "arg3" ]
        #then
            #export ENABLE_FEATURE_2=Y

        #elif [ $var == "arg4" ]
        #then
            #export ENABLE_FEATURE_3=Y
        #else
            #echo "ERROR: unrecognised argument '$var'";
            #exit 1
        #fi
    #done
#else
   #echo "ERROR: No inputs parameters provided to the scripts."
    #echo "Usage: source exports_file.sh <plaforms> <feature1> <feature2> <feature3>"
#fi

Answer 2

case 语句将简化您的代码。不过，首先，当你发现错误时尽快退出，这样你剩下的代码就不需要缩进了。

if [ $# = 0 ]; then
    echo "ERROR: No inputs parameters provided to the scripts." >&2
    echo "Usage: source exports_file.sh <plaforms> <feature1> <feature2> <feature3>" >&2
    exit 1
fi

platform=
shift

echo "INFO: Setting common exports for $platform" >&2
case $platform in 
    1234|1235|1236) export PLATFORM=9$platform ;;
    *) echo "ERROR: Exports are not defined for $platform" >&2
       exit 1 ;;
esac


# Check for feature based exports <feature1> <feature2> <feature3>
for var in "$@"
do
    case $var in
      arg2) export ENABLE_FEATURE_1=Y ;;
      arg3) export ENABLE_FEATURE_2=Y ;;
      arg4) export ENABLE_FEATURE_3=Y ;;
      *) echo "ERROR: unrecognized argument '$var'" >&2
         exit 1;;
    esac
done

检查作为输入提供给 shell 脚本的可变数量的位置参数的有效性

Check the validity of variable number of positional parameters provided as input to a shell script

linux

bash

shell

sh