getopts for parsing both long and short options

Question

I already have a script that accepts only SHORT OPTIONS, and I want to extend the same script so as to pass the respective LONG OPTIONS. The existing code is given below.

while getopts :t:c: name; do   
   case name
    t) first=$OPTARG;;
    c) second=$OPTARG;;
    *) echo 'Invalid option'; break;;   
   esac 
done 
SHIFT $((OPTIND-1))

This works for short options, but how can I extend the same code to allow long option parsing?

Answer 1

Given the inconsistent options available, I tend to roll my own; e.g.

SWITCH=false
VAL=default
while [ "$#" -gt 0 ] ; do
  case "${1}" in
    (-s|--switch) SWITCH=true ;;
    (-v|--value)  VAL="${2}" ; shift ;;
    (-v?*)        VAL="${1#-v}" ;;
    (--value=?*)  VAL="${1#--value=}" ;;
  esac
  shift
done

Answer 2

This is simple, but the documentation is only in the getopt() man page from Solaris and in the getopts documentation from bosh:

http://schilytools.sourceforge.net/man/man1/bosh.1.html

scroll down to page 47 in the version from December 2019.

Let me edit your example:

while getopts ":t:(test)c:(call)" name; do   
    case $name in
    t) first=$OPTARG;;
    c) second=$OPTARG;;
    :) echo "Missing argument for -$OPTARG"; break;;
    *) echo 'Invalid option'; break;;   
    esac
done
shift $((OPTIND-1))

Note that you may need to quote arguments that contain parenthesis....

This accepts -c and --call.

Note that this only works with

• bosh, the maintained POSIX enhanced Bourne Shell from schilytools on any OS
• sh , the old Bourne Shell on Solaris 10
• ksh93 on any OS

bosh in addition also supports UNIX style long options -long if optstring starts with ().

Both, ksh93 and bosh in addition support options that start with + if optstringstarts with a +. In such a case, $name contains +c instead of c, if the program has been called with +c.

BTW: Only boshsupports a method to support long options that have no adjacent short option. See bosh man page.

I am the author of schilytools.