Shell Script parameters

Question

What is the best way to parse parameters in shell script command, and then validate it?

For example bash someScript.sh -p <some_path> -o <some_other_param> -i (User forget to provide value).

How to parse all of this parameters and when user forget to input some parameters or value of this parameter show some error message and terminate executing of script?

Use `getopts`, of course. It's described in the bash man page. — Barmar, Nov 28 '13 at 09:27
Simple solution: http://stackoverflow.com/questions/20101929/bash-script-how-to-test-for-parameter-pairs — Sergey Fedorov, Nov 28 '13 at 09:41

johnsyweb · Accepted Answer · 2013-11-28T09:43:37.060

4

Use getopt or getopts.

There are lots of examples on this site, but here is one more:

#!/usr/bin/env bash

p_set=false
o_set=false
i_set=false
while getopts p:o:i: OPT; do
    case "${OPT}" in
        p)
            p_set=true
            some_path=${OPTARG}
            ;;
        o)
            o_set=true
            some_other_param=${OPTARG}
            ;;
        i)
            i_set=true
            # Process ${OPTARG} or report error if it's not provided
            ;;
    esac
done

if ! $i_set ; then
    echo "-i must be provided"
fi

edited Nov 28 '13 at 09:43

answered Nov 28 '13 at 09:27

johnsyweb

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And how to check when user enter param and forget value? – Procurares Nov 28 '13 at 09:32
I was adding that detail as you commented. – johnsyweb Nov 28 '13 at 09:40
1

That can only happen if the user types `-i` (for example) as the last argument when you expect an option. Then `getopts` will report an error. – Jonathan Leffler Nov 28 '13 at 09:41

score 0 · Answer 2 · answered Nov 28 '13 at 09:28

0

Search man pages of getopts. You would easily implement it.

answered Nov 28 '13 at 09:28

Mandar Pande

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score 0 · Answer 3 · answered Nov 28 '13 at 09:36

0

Of course, the man page is always a good resource. But there are also good examples on the net. When dealing with getopts, I always refer to http://mywiki.wooledge.org/BashFAQ/035. Pretty much everything you'd want to know can be found there.

answered Nov 28 '13 at 09:36

pfnuesel

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Shell Script parameters

3 Answers3

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