[SOLVED] Bash: loop through parameters with shift

Ramurd · 03-01-2012, 05:17 AM

Hi there,

I have the following scriptlet:

Code:

while [[ "${1:0:1}" == "-" ]]
do
        case ${1} in
                "-c")
                        shift
                        echo "Matched -c"
                        dbname=${1}
                        ;;
                "-u")
                        shift
                        echo "Matched -u"
                        dbuser=${1}
                        ;;
                "-p")
                        shift
                        echo "Matched -p"
                        dbpass=${1}
                        ;;
                *)
                        break
                        ;;
        esac
done

if [[ ! -z "${dbname}" ]]
then
   echo "Connecting to db ${dbname} with user ${dbuser} and password ${dbpass}"
fi

echo ${*}

This is some work in progress; hence the simple echo instead of really connecting. The idea is quite simple: if this script is called with the parameters -c, -p and -u these values must NOT be echoed by "echo ${*} and the variables have to be set according to the parameters given.

so I need to be able to run my script like this:

Code:

script.sh -c db1 -u dbuser -p dbpass run this.sql

and

Code:

script.sh echo oh my goodness

Somehow, my thinking went wrong and the while loop only takes the first parameter, the shifting done within the case statement (if applicable) does not seem to affect the while loop.

Unfortunately I have bash version 3.2.51, and no means to upgrade it to bash 4.

Getopts would not help me alot here I reckon, because I need to strip stuff from my parameter list; I had hoped shift would let me.

jhwilliams · 03-01-2012, 05:44 AM

You never shift after you get the OPT's OPTARG. This should fix that problem:

Code:

...
                        shift
                        echo "Matched -c"
                        dbname=${1}
                        shift
                        ;;
                "-u")
                        shift
                        echo "Matched -u"
                        dbuser=${1}
                        shift
                        ;;
                "-p")
                        shift
                        echo "Matched -p"
                        dbpass=${1}
                        shift
                        ;;
                *)
                  ...

catkin · 03-01-2012, 05:48 AM

The script shits the option out of the way but not the option argument. Fix by adding a shift statement after the esac.

EDIT: beaten to it by jhwilliams

EDIT2: nothing in what has been shown so far precludes using getopts

Ramurd · 03-01-2012, 05:49 AM

how simple things can be... thanks; that was it.