Bash脚本-将变量包装在引号中

Question

I was doing some reading here and it suggested that I wrap my variables in quotes just in case the value contains spaces.

If I have the following script:

#!/bin/bash

function checkDirectory()
{
    local checkDir=$1

    if [[ -d $checkDir ]] ; then 
        echo "File is directory"
    fi


}


checkDirectory "/home/someuser/Downloads/"

If I wrap my parameter, in this case, "/home/someuser/Downloads/" in quotes, do I still need to wrap $1 and checkDir in quotes as well?

Answer 1

No. You don't have to as $1 will be assigned to checkDir correctly and bash's [[ ]] won't do word splitting and your script will work as expected.

However, in case if you use sh test [ .. ] then you'll have a problem with:

if [ -d $checkDir ] ; then 
    echo "File is directory"
fi

So it's always good practice to quote your variables rather than having to remember it matters and when not.