Question

所以我有这个脚本，我希望脚本测试第二个条件，如果“if”为false，这是elif测试它是否为真。除非它是假的，它继续并测试下一个elif。基本上是多个“其他”。

#Basically It turns a argument into a variable. Because that can't 
#work in an if function.
#What the script is doing is its setting variables for the python script
#What vvTHISvv does is it turns the argument into a variable. 
if [[ "$1" != "" ]]; then
    VAR="$1"
else
    VAR=.
fi
if [[ "$2" != "" ]]; then
    VAR2="$2"
else
    VAR2=.
fi
if [[ "$3" != "" ]]; then
    VAR3="$3"
else
    VAR3=.
fi


if [[ ${2} = ${VAR2} ]]
#${2} =  ${2}
then
    echo "I am condition number 1"
    #outputs a number
    ./script.py "${VAR}" "`cat ${VAR2}` `echo ${VAR3}`"
elif [[ ${3} = "${VAR3}" ]]
#${3} = ${3}
then
    echo "I am condition number 2"
    #outputs a number

    ./script.py "${VAR}" "`echo ${VAR2}` `cat ${VAR3}`"
elif [[ ${2} = "${VAR2}" ]] || [[ ${3} = "${VAR3}" ]]
then
    echo "I am condition number 3"
    #outputs a number
    ./script.py "${VAR}" "`cat ${VAR2}` `cat ${VAR3}`"
else 
    echo "I am condition number 4"
    #outputs a number
    ./script.py "${VAR}" "${VAR2} ${VAR3}"
fi

如果我按照第一个条件运行，它就可以运行

I am condition number 1
#*Insert whatever that python script did. Lets say it outputs "2"

但是，如果我按照条件编号2进行测试

I am condition number 1
#*insert a bunch of errors
#related to the fact that its rolling based on the first "if"

它不起作用，只为条件号1滚动。

如果只有两个条件我会把“if”和“else”放在一起，但是你如何用四个条件来做呢。

无论如何VAR和$ {1}都是一样的，为什么一个变量是围绕着./script.py中的条件和参数是同一个事实的原因。并且你不能将这两者彼此相等地设置为IF语句中的条件。

Answer 1

使用case，省略（./script.py代码以显示逻辑的工作方式）：

# Assumes none of the variables contain a '#' -- change to some other
# nonexistent string if needed.
case "$2#$3" in 
    "${VAR2}#${VAR3}") echo both ;;
    "${VAR2}#"*)       echo 1st ;;
    *"#${VAR3}")       echo 2nd ;;
    *)                echo none ;;
esac

由于只将两个变量与两个相应的字符串进行比较，因此只有四种可能的结果。

case接受多行代码，就像if一样。使用问题中的第一个条件，代码将变为：

case "$2#$3" in 
    "${VAR2}#${VAR3}") echo both ;;
    "${VAR2}#"*)       echo "I am condition number 1"
                     ./script.py "${VAR}" "$(<${VAR2}) ${VAR3}" ;;
    *"#${VAR3}")       echo 2nd ;;
    *)                echo none ;;
esac

如果“if”为false，如何继续脚本？多个“别的”

1 个答案: