#! /bin/sh

# A portable, pluggable option parser for Bourne shell.
# Written by Gary V. Vaughan, 2010

# This is free software.  There is NO warranty; not even for
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
#
# Copyright (C) 2010-2019, 2021 Bootstrap Authors
#
# This file is dual licensed under the terms of the MIT license
# <https://opensource.org/license/MIT>, and GPL version 2 or later
# <http://www.gnu.org/licenses/gpl-2.0.html>.  You must apply one of
# these licenses when using or redistributing this software or any of
# the files within it.  See the URLs above, or the file `LICENSE`
# included in the Bootstrap distribution for the full license texts.

# Please report bugs or propose patches to:
# <https://github.com/gnulib-modules/bootstrap/issues>

# Set a version string for this script.
scriptversion=2019-02-19.15; # UTC


## ------ ##
## Usage. ##
## ------ ##

# This file is a library for parsing options in your shell scripts along
# with assorted other useful supporting features that you can make use
# of too.
#
# For the simplest scripts you might need only:
#
#   #!/bin/sh
#   . relative/path/to/funclib.sh
#   . relative/path/to/options-parser
#   scriptversion=1.0
#   func_options ${1+"$@"}
#   eval set dummy "$func_options_result"; shift
#   ...rest of your script...
#
# In order for the '--version' option to work, you will need to have a
# suitably formatted comment like the one at the top of this file
# starting with '# Written by ' and ending with '# Copyright'.
#
# For '-h' and '--help' to work, you will also need a one line
# description of your script's purpose in a comment directly above the
# '# Written by ' line, like the one at the top of this file.
#
# The default options also support '--debug', which will turn on shell
# execution tracing (see the comment above debug_cmd below for another
# use), and '--verbose' and the func_verbose function to allow your script
# to display verbose messages only when your user has specified
# '--verbose'.
#
# After sourcing this file, you can plug in processing for additional
# options by amending the variables from the 'Configuration' section
# below, and following the instructions in the 'Option parsing'
# section further down.

## -------------- ##
## Configuration. ##
## -------------- ##

# You should override these variables in your script after sourcing this
# file so that they reflect the customisations you have added to the
# option parser.

# The usage line for option parsing errors and the start of '-h' and
# '--help' output messages. You can embed shell variables for delayed
# expansion at the time the message is displayed, but you will need to
# quote other shell meta-characters carefully to prevent them being
# expanded when the contents are evaled.
usage='$progpath [OPTION]...'

# Short help message in response to '-h' and '--help'.  Add to this or
# override it after sourcing this library to reflect the full set of
# options your script accepts.
usage_message="\
       --debug        enable verbose shell tracing
   -W, --warnings=CATEGORY
                      report the warnings falling in CATEGORY [all]
   -v, --verbose      verbosely report processing
       --version      print version information and exit
   -h, --help         print short or long help message and exit
"

# Additional text appended to 'usage_message' in response to '--help'.
long_help_message="
Warning categories include:
       'all'          show all warnings
       'none'         turn off all the warnings
       'error'        warnings are treated as fatal errors"

# Help message printed before fatal option parsing errors.
fatal_help="Try '\$progname --help' for more information."



## ------------------------- ##
## Hook function management. ##
## ------------------------- ##

# This section contains functions for adding, removing, and running hooks
# in the main code.  A hook is just a list of function names that can be
# run in order later on.

# func_hookable FUNC_NAME
# -----------------------
# Declare that FUNC_NAME will run hooks added with
# 'func_add_hook FUNC_NAME ...'.
func_hookable ()
{
    $debug_cmd

    func_append hookable_fns " $1"
}


# func_add_hook FUNC_NAME HOOK_FUNC
# ---------------------------------
# Request that FUNC_NAME call HOOK_FUNC before it returns.  FUNC_NAME must
# first have been declared "hookable" by a call to 'func_hookable'.
func_add_hook ()
{
    $debug_cmd

    case " $hookable_fns " in
      *" $1 "*) ;;
      *) func_fatal_error "'$1' does not accept hook functions." ;;
    esac

    eval func_append ${1}_hooks '" $2"'
}


# func_remove_hook FUNC_NAME HOOK_FUNC
# ------------------------------------
# Remove HOOK_FUNC from the list of hook functions to be called by
# FUNC_NAME.
func_remove_hook ()
{
    $debug_cmd

    eval ${1}_hooks='`$ECHO "\$'$1'_hooks" |$SED "s| '$2'||"`'
}


# func_propagate_result FUNC_NAME_A FUNC_NAME_B
# ---------------------------------------------
# If the *_result variable of FUNC_NAME_A _is set_, assign its value to
# *_result variable of FUNC_NAME_B.
func_propagate_result ()
{
    $debug_cmd

    func_propagate_result_result=:
    if eval "test \"\${${1}_result+set}\" = set"
    then
      eval "${2}_result=\$${1}_result"
    else
      func_propagate_result_result=false
    fi
}


# func_run_hooks FUNC_NAME [ARG]...
# ---------------------------------
# Run all hook functions registered to FUNC_NAME.
# It's assumed that the list of hook functions contains nothing more
# than a whitespace-delimited list of legal shell function names, and
# no effort is wasted trying to catch shell meta-characters or preserve
# whitespace.
func_run_hooks ()
{
    $debug_cmd

    case " $hookable_fns " in
      *" $1 "*) ;;
      *) func_fatal_error "'$1' does not support hook functions." ;;
    esac

    eval _G_hook_fns=\$$1_hooks; shift

    for _G_hook in $_G_hook_fns; do
      func_unset "${_G_hook}_result"
      eval $_G_hook '${1+"$@"}'
      func_propagate_result $_G_hook func_run_hooks
      if $func_propagate_result_result; then
        eval set dummy "$func_run_hooks_result"; shift
      fi
    done
}



## --------------- ##
## Option parsing. ##
## --------------- ##

# In order to add your own option parsing hooks, you must accept the
# full positional parameter list from your hook function.  You may remove
# or edit any options that you action, and then pass back the remaining
# unprocessed options in '<hooked_function_name>_result', escaped
# suitably for 'eval'.
#
# The '<hooked_function_name>_result' variable is automatically unset
# before your hook gets called; for best performance, only set the
# *_result variable when necessary (i.e. don't call the 'func_quote'
# function unnecessarily because it can be an expensive operation on some
# machines).
#
# Like this:
#
#    my_options_prep ()
#    {
#        $debug_cmd
#
#        # Extend the existing usage message.
#        usage_message=$usage_message'
#      -s, --silent       don'\''t print informational messages
#    '
#        # No change in '$@' (ignored completely by this hook).  Leave
#        # my_options_prep_result variable intact.
#    }
#    func_add_hook func_options_prep my_options_prep
#
#
#    my_silent_option ()
#    {
#        $debug_cmd
#
#        args_changed=false
#
#        # Note that, for efficiency, we parse as many options as we can
#        # recognise in a loop before passing the remainder back to the
#        # caller on the first unrecognised argument we encounter.
#        while test $# -gt 0; do
#          opt=$1; shift
#          case $opt in
#            --silent|-s) opt_silent=:
#                         args_changed=:
#                         ;;
#            # Separate non-argument short options:
#            -s*)         func_split_short_opt "$_G_opt"
#                         set dummy "$func_split_short_opt_name" \
#                             "-$func_split_short_opt_arg" ${1+"$@"}
#                         shift
#                         args_changed=:
#                         ;;
#            *)           # Make sure the first unrecognised option "$_G_opt"
#                         # is added back to "$@" in case we need it later,
#                         # if $args_changed was set to 'true'.
#                         set dummy "$_G_opt" ${1+"$@"}; shift; break ;;
#          esac
#        done
#
#        # Only call 'func_quote' here if we processed at least one argument.
#        if $args_changed; then
#          func_quote eval ${1+"$@"}
#          my_silent_option_result=$func_quote_result
#        fi
#    }
#    func_add_hook func_parse_options my_silent_option
#
#
#    my_option_validation ()
#    {
#        $debug_cmd
#
#        $opt_silent && $opt_verbose && func_fatal_help "\
#    '--silent' and '--verbose' options are mutually exclusive."
#    }
#    func_add_hook func_validate_options my_option_validation
#
# You'll also need to manually amend $usage_message to reflect the extra
# options you parse.  It's preferable to append if you can, so that
# multiple option parsing hooks can be added safely.


# func_options_finish [ARG]...
# ----------------------------
# Finishing the option parse loop (call 'func_options' hooks ATM).
func_options_finish ()
{
    $debug_cmd

    func_run_hooks func_options ${1+"$@"}
    func_propagate_result func_run_hooks func_options_finish
}


# func_options [ARG]...
# ---------------------
# All the functions called inside func_options are hookable. See the
# individual implementations for details.
func_hookable func_options
func_options ()
{
    $debug_cmd

    _G_options_quoted=false

    for my_func in options_prep parse_options validate_options options_finish
    do
      func_unset func_${my_func}_result
      func_unset func_run_hooks_result
      eval func_$my_func '${1+"$@"}'
      func_propagate_result func_$my_func func_options
      if $func_propagate_result_result; then
        eval set dummy "$func_options_result"; shift
        _G_options_quoted=:
      fi
    done

    $_G_options_quoted || {
      # As we (func_options) are top-level options-parser function and
      # nobody quoted "$@" for us yet, we need to do it explicitly for
      # caller.
      func_quote eval ${1+"$@"}
      func_options_result=$func_quote_result
    }
}


# func_options_prep [ARG]...
# --------------------------
# All initialisations required before starting the option parse loop.
# Note that when calling hook functions, we pass through the list of
# positional parameters.  If a hook function modifies that list, and
# needs to propagate that back to rest of this script, then the complete
# modified list must be put in 'func_run_hooks_result' before returning.
func_hookable func_options_prep
func_options_prep ()
{
    $debug_cmd

    # Option defaults:
    opt_verbose=false
    opt_warning_types=

    func_run_hooks func_options_prep ${1+"$@"}
    func_propagate_result func_run_hooks func_options_prep
}


# func_parse_options [ARG]...
# ---------------------------
# The main option parsing loop.
func_hookable func_parse_options
func_parse_options ()
{
    $debug_cmd

    _G_parse_options_requote=false
    # this just eases exit handling
    while test $# -gt 0; do
      # Defer to hook functions for initial option parsing, so they
      # get priority in the event of reusing an option name.
      func_run_hooks func_parse_options ${1+"$@"}
      func_propagate_result func_run_hooks func_parse_options
      if $func_propagate_result_result; then
        eval set dummy "$func_parse_options_result"; shift
        # Even though we may have changed "$@", we passed the "$@" array
        # down into the hook and it quoted it for us (because we are in
        # this if-branch).  No need to quote it again.
        _G_parse_options_requote=false
      fi

      # Break out of the loop if we already parsed every option.
      test $# -gt 0 || break

      # We expect that one of the options parsed in this function matches
      # and thus we remove _G_opt from "$@" and need to re-quote.
      _G_match_parse_options=:
      _G_opt=$1
      shift
      case $_G_opt in
        --debug|-x)   debug_cmd='set -x'
                      func_echo "enabling shell trace mode" >&2
                      $debug_cmd
                      ;;

        --no-warnings|--no-warning|--no-warn)
                      set dummy --warnings none ${1+"$@"}
                      shift
		      ;;

        --warnings|--warning|-W)
                      if test $# = 0 && func_missing_arg $_G_opt; then
                        _G_parse_options_requote=:
                        break
                      fi
                      case " $warning_categories $1" in
                        *" $1 "*)
                          # trailing space prevents matching last $1 above
                          func_append_uniq opt_warning_types " $1"
                          ;;
                        *all)
                          opt_warning_types=$warning_categories
                          ;;
                        *none)
                          opt_warning_types=none
                          warning_func=:
                          ;;
                        *error)
                          opt_warning_types=$warning_categories
                          warning_func=func_fatal_error
                          ;;
                        *)
                          func_fatal_error \
                             "unsupported warning category: '$1'"
                          ;;
                      esac
                      shift
                      ;;

        --verbose|-v) opt_verbose=: ;;
        --version)    func_version ;;
        -\?|-h)       func_usage ;;
        --help)       func_help ;;

	# Separate optargs to long options (plugins may need this):
	--*=*)        func_split_equals "$_G_opt"
	              set dummy "$func_split_equals_lhs" \
                          "$func_split_equals_rhs" ${1+"$@"}
                      shift
                      ;;

       # Separate optargs to short options:
        -W*)
                      func_split_short_opt "$_G_opt"
                      set dummy "$func_split_short_opt_name" \
                          "$func_split_short_opt_arg" ${1+"$@"}
                      shift
                      ;;

        # Separate non-argument short options:
        -\?*|-h*|-v*|-x*)
                      func_split_short_opt "$_G_opt"
                      set dummy "$func_split_short_opt_name" \
                          "-$func_split_short_opt_arg" ${1+"$@"}
                      shift
                      ;;

        --)           _G_parse_options_requote=: ; break ;;
        -*)           func_fatal_help "unrecognised option: '$_G_opt'" ;;
        *)            set dummy "$_G_opt" ${1+"$@"}; shift
                      _G_match_parse_options=false
                      break
                      ;;
      esac

      if $_G_match_parse_options; then
        _G_parse_options_requote=:
      fi
    done

    if $_G_parse_options_requote; then
      # save modified positional parameters for caller
      func_quote eval ${1+"$@"}
      func_parse_options_result=$func_quote_result
    fi
}


# func_validate_options [ARG]...
# ------------------------------
# Perform any sanity checks on option settings and/or unconsumed
# arguments.
func_hookable func_validate_options
func_validate_options ()
{
    $debug_cmd

    # Display all warnings if -W was not given.
    test -n "$opt_warning_types" || opt_warning_types=" $warning_categories"

    func_run_hooks func_validate_options ${1+"$@"}
    func_propagate_result func_run_hooks func_validate_options

    # Bail if the options were screwed!
    $exit_cmd $EXIT_FAILURE
}



## ----------------- ##
## Helper functions. ##
## ----------------- ##

# This section contains the helper functions used by the rest of the
# hookable option parser framework in ascii-betical order.


# func_fatal_help ARG...
# ----------------------
# Echo program name prefixed message to standard error, followed by
# a help hint, and exit.
func_fatal_help ()
{
    $debug_cmd

    eval \$ECHO \""Usage: $usage"\"
    eval \$ECHO \""$fatal_help"\"
    func_error ${1+"$@"}
    exit $EXIT_FAILURE
}


# func_help
# ---------
# Echo long help message to standard output and exit.
func_help ()
{
    $debug_cmd

    func_usage_message
    $ECHO "$long_help_message"
    exit 0
}


# func_missing_arg ARGNAME
# ------------------------
# Echo program name prefixed message to standard error and set global
# exit_cmd.
func_missing_arg ()
{
    $debug_cmd

    func_error "Missing argument for '$1'."
    exit_cmd=exit
}


# func_split_equals STRING
# ------------------------
# Set func_split_equals_lhs and func_split_equals_rhs shell variables
# after splitting STRING at the '=' sign.
test -z "$_G_HAVE_XSI_OPS" \
    && (eval 'x=a/b/c;
      test 5aa/bb/cc = "${#x}${x%%/*}${x%/*}${x#*/}${x##*/}"') 2>/dev/null \
    && _G_HAVE_XSI_OPS=yes

if test yes = "$_G_HAVE_XSI_OPS"
then
  # This is an XSI compatible shell, allowing a faster implementation...
  eval 'func_split_equals ()
  {
      $debug_cmd

      func_split_equals_lhs=${1%%=*}
      func_split_equals_rhs=${1#*=}
      if test "x$func_split_equals_lhs" = "x$1"; then
        func_split_equals_rhs=
      fi
  }'
else
  # ...otherwise fall back to using expr, which is often a shell builtin.
  func_split_equals ()
  {
      $debug_cmd

      func_split_equals_lhs=`expr "x$1" : 'x\([^=]*\)'`
      func_split_equals_rhs=
      test "x$func_split_equals_lhs=" = "x$1" \
        || func_split_equals_rhs=`expr "x$1" : 'x[^=]*=\(.*\)$'`
  }
fi #func_split_equals


# func_split_short_opt SHORTOPT
# -----------------------------
# Set func_split_short_opt_name and func_split_short_opt_arg shell
# variables after splitting SHORTOPT after the 2nd character.
if test yes = "$_G_HAVE_XSI_OPS"
then
  # This is an XSI compatible shell, allowing a faster implementation...
  eval 'func_split_short_opt ()
  {
      $debug_cmd

      func_split_short_opt_arg=${1#??}
      func_split_short_opt_name=${1%"$func_split_short_opt_arg"}
  }'
else
  # ...otherwise fall back to using expr, which is often a shell builtin.
  func_split_short_opt ()
  {
      $debug_cmd

      func_split_short_opt_name=`expr "x$1" : 'x\(-.\)'`
      func_split_short_opt_arg=`expr "x$1" : 'x-.\(.*\)$'`
  }
fi #func_split_short_opt


# func_usage
# ----------
# Echo short help message to standard output and exit.
func_usage ()
{
    $debug_cmd

    func_usage_message
    $ECHO "Run '$progname --help |${PAGER-more}' for full usage"
    exit 0
}


# func_usage_message
# ------------------
# Echo short help message to standard output.
func_usage_message ()
{
    $debug_cmd

    eval \$ECHO \""Usage: $usage"\"
    echo
    $SED -n 's|^# ||
        /^Written by/{
          x;p;x
        }
	h
	/^Written by/q' < "$progpath"
    echo
    eval \$ECHO \""$usage_message"\"
}


# func_version
# ------------
# Echo version message to standard output and exit.
# The version message is extracted from the calling file's header
# comments, with leading '# ' stripped:
#   1. First display the progname and version
#   2. Followed by the header comment line matching  /^# Written by /
#   3. Then a blank line followed by the first following line matching
#      /^# Copyright /
#   4. Immediately followed by any lines between the previous matches,
#      except lines preceding the intervening completely blank line.
# For example, see the header comments of this file.
func_version ()
{
    $debug_cmd

    printf '%s\n' "$progname $scriptversion"
    $SED -n '
        /^# Written by /!b
        s|^# ||; p; n

        :fwd2blnk
        /./ {
          n
          b fwd2blnk
        }
        p; n

        :holdwrnt
        s|^# ||
        s|^# *$||
        /^Copyright /!{
          /./H
          n
          b holdwrnt
        }

        s|\((C)\)[ 0-9,-]*[ ,-]\([1-9][0-9]* \)|\1 \2|
        G
        s|\(\n\)\n*|\1|g
        p; q' < "$progpath"

    exit $?
}


# Local variables:
# mode: shell-script
# sh-indentation: 2
# eval: (add-hook 'before-save-hook 'time-stamp)
# time-stamp-pattern: "30/scriptversion=%:y-%02m-%02d.%02H; # UTC"
# time-stamp-time-zone: "UTC"
# End:
