#!/bin/sh

set -- `getopt "abco:" "$@"`

a= b= c= o=
while :
do
    case "$1" in
    -a) a=1;;
    -b) b=1;;
    -c) c=1;;
    -o) shift; o="$1";;
    --) break;;
    esac
shift
done
shift # get rid of --
# rest of script...
# e.g.
ls -l $@

space are evil. the easy way to to prevent them by quoting on the commandline.

This wil not help as far as quoting will be removed by getopt

hi all...


i have come across the posting ....
can any one please explain the code..

set -- `getopt "abco:" "$@"`

a= b= c= o=
while :
do
case "$1" in
-a) a=1;;
-b) b=1;;
-c) c=1;;
-o) shift; o="$1";;
--) break;;
esac
shift
done
shift # get rid of --
# rest of script...
# e.g.
ls -l $@

.....


what will set -- `getopt "abco:" "$@"` do and so on.

$@ is all positional parameters, i.e. if you execute command attr0 attr1 then $@ is equal to attr0 attr1

The Bourne Shell set command sets positional parameters to the getopt's output, i.e. if getopt returns something like -a -b -- test then $@ will be equal to -a -b -- test

Note: '--' is used in set command to resolve problems with parameters that begins with '-' character

In while loop positional parameters are being processed till '--' ($1 refers to first positional parameter, shift deletes first positional parameter)

Thanks a lot....

With KSH you can use getopts :

#!/bin/ksh

while getopts abco: name
do
   case $name in
      a)  a=1;;
      b)  b=1;;
      c)  c=1;;
      o)  o="$OPTARG";;
   esac
done

shift $(($OPTIND -1))
# rest of script...
# e.g.
ls -l $@