bash script 'for each command line argument'

true_atlantis · 03-27-2006, 02:09 PM

how do i traverse through the command line arguments? is there something which represents a list or array of the arguments (sort of like $# is the number of arguments). this is what i was trying, but its not working to well..

Code:

CTR=$#

while [ $CTR -gt 0 ]
do
        echo $$CTR
        CTR=$(expr $CTR - 1)
done

any help?

true_atlantis · 03-27-2006, 02:12 PM

just figured it out...

Code:

for ARG in $*
do
        echo $ARG
done

mizzouece · 04-08-2008, 07:38 PM

A more better solution (IMHO) is:

Code:

#!/bin/bash

foo ()
{
    for ARG in "$@"
    do
        echo $ARG
    done
}

# try it out
foo a b "c d" 'e f'

The output produced is:

Code:

a
b
c d
e f

If you instead use $*, the output changes as follows:

Code:

foo ()
{
    for ARG in $*
    do
        echo $ARG
    done
}

foo a b "c d" 'e f'

Output:
a
b
c
d
e
f

amamar5 · 01-28-2009, 01:51 PM

I know this is an old topic but just in case you come across this page through a search...

I know this doesn't use for each but its a nice way to handle command line arguments. I found this example elsewhere (can't remember) and I tweaked it a bit. It's not complete but it should get you started.

Code:

#IF NO ARGUMENTS WERE PROVIDED
function USAGE ()
{
    echo ""
    echo "USAGE: "
    echo "    ineff.sh [-?dh]"
    echo ""
    echo "OPTIONS:"
    echo "    -d  date of logfiles (format: yyyymmdd)"
    echo "    -h  logfile (format: 12 or 1[2-4])"
    echo "    -?  this usage information"
    echo ""
    echo "EXAMPLE:"
    echo "    ineff.sh -d 20060801 -h 2[12]"
    echo ""
    exit $E_OPTERROR    # Exit and explain usage, if no argument(s) given.
}

#PROCESS ARGS
while getopts ":d:h:?" Option
do
    case $Option in
        d    ) DT=$OPTARG;;
        h    ) HR=$OPTARG;;
        ?    ) USAGE
               exit 0;;
        *    ) echo ""
               echo "Unimplemented option chosen."
               USAGE   # DEFAULT
    esac
done


shift $(($OPTIND - 1))
#  Decrements the argument pointer so it points to next argument.
#  $1 now references the first non option item supplied on the command line
#+ if one exists.