bash args parser

arg_parser.sh

#
# Parses and argument from the command line
# the format must be arg <value>
#Ex:
# parse_arg result "-ip" "$@"
# [[ $? -eq 0 ]] && echo "IP: $result" || echo "Param -ip not found"
# parse_arg result "-m" "$@"
# [[ $? -eq 0 ]] && echo "MSG: $result" || echo "Param -m not found"
# where your command line arguments could be: -ip 127.0.0.1 -m "Hello Mr. Sapiens"
#
function parse_arg()
{
  [[ -n "$1" ]] && [[ -n "$2" ]] && [[ -n "$3" ]] || return -1;
  __ret_var_name__=$1;shift
  argName=$1;shift;
  until [ -z "$1" ]; do
    [[ "$1" == "$argName" ]] &&  eval $__ret_var_name__="'$2'" && return 0;
    shift;
  done
  return -1;
}


#
# or using getopts

while getopts “ht:r:p:v” OPTION; do
     case $OPTION in
         h)
             usage
             exit 1
             ;;
         i)
             IP=$OPTARG
             ;;
         p)
             POSRT=$OPTARG
             ;;
         ?)
             usage
             exit
             ;;
     esac
done