Question

I am writing a shell script where parameter will be a path to a location. I am using readlink -f command to get the absolute path of the path send by user. Suppose if the path send by the user has spaces like,

    /home/stack over flow/location

I am excepting the user to send with quotes like

    "/home/stack over flow/location"

I have 2 issues here,

1) Even though if the path is passed with quotes, when I iterate over $@, quotes are suppressed and get path without quotes.

2) I did a work around to check if the parameter contain spaces and I add explicitly like

    if [[ $1 = *\ * ]] ; then
           temp=\"$1\"
    fi

where I added quotes ” explicitly, but the problem now I am facing is even though I added variable with spaces now readlink is not working.
When I do

    full_path=`readlink -f ${temp}`

Its saying
usage: readlink [-n] [-f] symlink

If I execute it as a normal unix command in shell like

       readlink -f "/home/stack over flow/location"

which is working and I am getting full path. Why even I append the spaces readlink is not working in shell script? Please help me out with this.

Answer 1

Well it makes sense that you get the path without quotes in the script parameters: the quotes are meant for the shell processing the call of your script, not for the script itself.
I assume you call the command like this:

./test "/home/stack over flow/location"

where ‘test’ is the script you implement. The quotes around the path make sure the shell that executes this command treats the path as one single argument, not as three separate strings as it would do without the quotes. But the quotes are not treated as part of the parameter itself. So when the parameter is handed over to your script you get one single parameter holding the whole path, not a parameter holding a modified string based on the path: the string with padded quotes.

You can use that paramter without problems. Just put quotes around it again:

readlink -f "$@"

will protect the blanks contained in the specified path, just as in the original call.