CODEWITHSUNDEEP
bashgetopt
Hortitude
Hortitude

Reputation: 14058

How to call getopts in bash multiple times

I have a common library that I use from several scripts that parses command line options, however I also want my individual scripts to be able to process arguments as well... e.g.

common.sh:

function get_options {
    echo -e "in getoptions"
    echo $OPTIND
    while getopts ":ab:" optionName; do
       [ ... processing code ... ]
    done
}

a.sh

. ./common.sh

function get_local_options {
    echo -e "in getoptions"
    echo $OPTIND
    while getopts ":xy:" optionName; do
       [ ... processing code ... ]
    done
}

get_local_options $*
OPTIND=1
get_options $*

The problem si that if I call a.sh with:

a.sh -x -y foo -a -b bar

get_options stops processing at "foo" as it stops at the first "non-option"

Any way around this without rewriting things myself?

Upvotes: 4

Views: 5750

Answers (5)

Corin
Corin

Reputation: 2467

There are some good answers here but I think there is a simple solution: you need to increment OPTIND instead of resetting it to 1. i.e.

a.sh

. ./common.sh

function get_local_options {
    echo -e "in getoptions"
    echo $OPTIND
    while getopts ":xy:" optionName; do
       [ ... processing code ... ]
    done
}

get_local_options $*
(( OPTIND++ ))
get_options $*

In this way you will skip the word foo in the args list.

Upvotes: 0

ack
ack

Reputation: 7572

Just have your common script provide a list of common options and functions for handling those, then have the other scripts add to the option list any options which they can handle:

common.sh

OPTS="ab:hv"

common_usage() {
  echo "Common options:"
  echo "  -a     ..."
  echo "  -b arg ..."
  echo "  -h     Show usage"
  echo "  -v     Be verbose"
}

handle_common_opts() {
  case "$1" in
    a) handle_opt_a ;;
    b) handle_opt_b "$2" ;;
    h) usage; exit 0 ;;
    v) be_verbose ;;
  esac
}

a.sh

. common.sh

OPTS="${OPTS}xy:"

usage() {
  echo "Usage: $PROG [options] [arguments...]"
  echo
  common_usage
  echo
  echo "Specific options:"
  echo "  -x     ..."
  echo "  -y arg ..."
}

while getopts "$OPTS" OPT; do
  handle_common_opts "$OPT" "$OPTARG"
  case "$OPT" in
    x) handle_opt_x ;;
    y) handle_opt_y "$OPTARG" ;;
    \?) usage; exit 1 ;;
  esac
done
shift $((OPTIND-1))

handle_remaining_args "$@"

This has the following advantages: no need to play tricks with the internal houskeeping of getopts, the user can specify common and specific options in any order, it handles unrecognized options in a single place, and also makes the usage functions easier to maintain.

Upvotes: 2

Bishop B
Bishop B

Reputation: 91

foo() {
  unset OPTIND
  while getopts ...
  do
  done
}

Upvotes: 9

dubiousjim
dubiousjim

Reputation: 4802

I think you'll need to have your first getopts processor build a list of command line elements it didn't handle. Also, it will have to ignore the return value of the getopts call: getopts might return non-zero because it's hitting an argument to a command-line switch that it doesn't know how to process. So the first getopts processor needs to go to the end of the command-line. You can't trust its own judgments about when the options have stopped and the arguments have started. (Well, once you get two arguments in a row you could presumably skip the rest, but I'll leave that as an exercise.)

Something like this, then:

#!/bin/bash

UNHANDLED=()

function getxy {
  while ((OPTIND<=$#)); do
    if getopts ":xy:" opt; then
      case $opt in
        x|y) echo "getxy opt=$<$opt> OPTARG=<$OPTARG>";;
        *) UNHANDLED+=(-$OPTARG);;
      esac
    else
        UNHANDLED+=(${!OPTIND})
        let OPTIND++
    fi
  done
}

function getab {
  while getopts ":ab:" opt; do
  case $opt in
    a|b) echo "getab opt=$<$opt> OPTARG=<$OPTARG>";;
    *) echo "getab * opt=<$opt> OPTARG=<$OPTARG>";;
  esac
  done
}

echo "--- getxy ---"
OPTIND=1
getxy "$@"
# now we reset OPTIND and parse again using the UNHANDLED array
echo "--- getab ---"
OPTIND=1
set -- "${UNHANDLED[@]}"
getab "$@"
# now we get remaining args
shift $((OPTIND-1))
for arg; do
    echo "arg=<$arg>"
done

Upvotes: 0

Alok Singhal
Alok Singhal

Reputation: 96111

I managed to get this to work, not sure if this is what you want:

$ cat common.sh
function get_options {
    while getopts ":ab:" optionName
    do
        echo "get_options: OPTARG: $OPTARG, optionName: $optionName"
    done
}
$ cat a.sh
#!/bin/bash

. ./common.sh

function get_local_options {
    while getopts ":xy:" optionName; do
        case $optionName in
            x|y) 
                echo "get_local_options: OPTARG: $OPTARG, optionName: $optionName"
                last=$OPTIND;;
            *) echo "get_local_options, done with $optionName"
                break;;
        esac;
    done
}

last=1
get_local_options $*
shift $(($last - 1))
OPTIND=1
get_options $*
$ ./a.sh -x -y foo -a -b bar
get_local_options: OPTARG: , optionName: x
get_local_options: OPTARG: foo, optionName: y
get_local_options, done with ?
get_options: OPTARG: , optionName: a
get_options: OPTARG: bar, optionName: b
$ ./a.sh -a -b bar
get_local_options, done with ?
get_options: OPTARG: , optionName: a
get_options: OPTARG: bar, optionName: b

Upvotes: 1

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