#!/bin/sh
#
# Copyright (C) 2002-2008, 2010-2013 Free Software Foundation, Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

progname=$0
package=gnulib

# func_usage
# outputs to stdout the --help usage message.
func_usage ()
{
  echo "\
Usage: posix-modules

Lists the gnulib modules that implement POSIX interfaces.

Report bugs to <bug-gnulib@gnu.org>."
}

# func_version
# outputs to stdout the --version message.
func_version ()
{
  func_gnulib_dir
  if test -d "$gnulib_dir"/.git \
     && (git --version) >/dev/null 2>/dev/null \
     && (date --version) >/dev/null 2>/dev/null; then
    # gnulib checked out from git.
    sed_extract_first_date='/^Date/{
s/^Date:[	 ]*//p
q
}'
    date=`cd "$gnulib_dir" && git log ChangeLog | sed -n -e "$sed_extract_first_date"`
    # Turn "Fri Mar 21 07:16:51 2008 -0600" into "Mar 21 2008 07:16:51 -0600".
    sed_year_before_time='s/^[^ ]* \([^ ]*\) \([0-9]*\) \([0-9:]*\) \([0-9]*\) /\1 \2 \4 \3 /'
    date=`echo "$date" | sed -e "$sed_year_before_time"`
    # Use GNU date to compute the time in GMT.
    date=`date -d "$date" -u +"%Y-%m-%d %H:%M:%S"`
    version=' '`cd "$gnulib_dir" && ./build-aux/git-version-gen /dev/null | sed -e 's/-dirty/-modified/'`
  else
    # gnulib copy without versioning information.
    date=`sed -e 's/ .*//;q' "$gnulib_dir"/ChangeLog`
    version=
  fi
  year=`"$gnulib_dir"/build-aux/mdate-sh "$self_abspathname" | sed 's,^.* ,,'`
  echo "\
posix-modules (GNU $package $date)$version
Copyright (C) $year Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by" "Bruno Haible"
}

# func_exit STATUS
# exits with a given status.
# This function needs to be used, rather than 'exit', when a 'trap' handler is
# in effect that refers to $?.
func_exit ()
{
  (exit $1); exit $1
}

# func_gnulib_dir
# locates the directory where the gnulib repository lives
# Input:
# - progname                 name of this program
# Sets variables
# - self_abspathname         absolute pathname of this program
# - gnulib_dir               absolute pathname of gnulib repository
func_gnulib_dir ()
{
  case "$progname" in
    /*) self_abspathname="$progname" ;;
    */*) self_abspathname=`pwd`/"$progname" ;;
    *)
      # Look in $PATH.
      # Iterate through the elements of $PATH.
      # We use IFS=: instead of
      #   for d in `echo ":$PATH:" | sed -e 's/:::*/:.:/g' | sed -e 's/:/ /g'`
      # because the latter does not work when some PATH element contains spaces.
      # We use a canonicalized $pathx instead of $PATH, because empty PATH
      # elements are by definition equivalent to '.', however field splitting
      # according to IFS=: loses empty fields in many shells:
      #   - /bin/sh on OSF/1 and Solaris loses all empty fields (at the
      #     beginning, at the end, and in the middle),
      #   - /bin/sh on IRIX and /bin/ksh on IRIX and OSF/1 lose empty fields
      #     at the beginning and at the end,
      #   - GNU bash, /bin/sh on AIX and HP-UX, and /bin/ksh on AIX, HP-UX,
      #     Solaris lose empty fields at the end.
      # The 'case' statement is an optimization, to avoid evaluating the
      # explicit canonicalization command when $PATH contains no empty fields.
      self_abspathname=
      if test "${PATH_SEPARATOR+set}" != set; then
        # Determine PATH_SEPARATOR by trying to find /bin/sh in a PATH which
        # contains only /bin. Note that ksh looks also at the FPATH variable,
        # so we have to set that as well for the test.
        PATH_SEPARATOR=:
        (PATH='/bin;/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 \
          && { (PATH='/bin:/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 \
                 || PATH_SEPARATOR=';'
             }
      fi
      if test "$PATH_SEPARATOR" = ";"; then
        # On Windows, programs are searched in "." before $PATH.
        pathx=".;$PATH"
      else
        # On Unix, we have to convert empty PATH elements to ".".
        pathx="$PATH"
        case :$PATH: in
          *::*)
            pathx=`echo ":$PATH:" | sed -e 's/:::*/:.:/g' -e 's/^://' -e 's/:\$//'`
            ;;
        esac
      fi
      save_IFS="$IFS"
      IFS="$PATH_SEPARATOR"
      for d in $pathx; do
        IFS="$save_IFS"
        test -z "$d" && d=.
        if test -x "$d/$progname" && test ! -d "$d/$progname"; then
          self_abspathname="$d/$progname"
          break
        fi
      done
      IFS="$save_IFS"
      if test -z "$self_abspathname"; then
        func_fatal_error "could not locate the posix-modules program - how did you invoke it?"
      fi
      ;;
  esac
  while test -h "$self_abspathname"; do
    # Resolve symbolic link.
    linkval=`func_readlink "$self_abspathname"`
    test -n "$linkval" || break
    case "$linkval" in
      /* ) self_abspathname="$linkval" ;;
      * ) self_abspathname=`echo "$self_abspathname" | sed -e 's,/[^/]*$,,'`/"$linkval" ;;
    esac
  done
  gnulib_dir=`echo "$self_abspathname" | sed -e 's,/[^/]*$,,'`
}

# func_tmpdir
# creates a temporary directory.
# Input:
# - progname                 name of this program
# Sets variable
# - tmp             pathname of freshly created temporary directory
func_tmpdir ()
{
  # Use the environment variable TMPDIR, falling back to /tmp. This allows
  # users to specify a different temporary directory, for example, if their
  # /tmp is filled up or too small.
  : ${TMPDIR=/tmp}
  {
    # Use the mktemp program if available. If not available, hide the error
    # message.
    tmp=`(umask 077 && mktemp -d "$TMPDIR/glXXXXXX") 2>/dev/null` &&
    test -n "$tmp" && test -d "$tmp"
  } ||
  {
    # Use a simple mkdir command. It is guaranteed to fail if the directory
    # already exists.  $RANDOM is bash specific and expands to empty in shells
    # other than bash, ksh and zsh.  Its use does not increase security;
    # rather, it minimizes the probability of failure in a very cluttered /tmp
    # directory.
    tmp=$TMPDIR/gl$$-$RANDOM
    (umask 077 && mkdir "$tmp")
  } ||
  {
    echo "$progname: cannot create a temporary directory in $TMPDIR" >&2
    func_exit 1
  }
}

# func_fatal_error message
# outputs to stderr a fatal error message, and terminates the program.
# Input:
# - progname                 name of this program
func_fatal_error ()
{
  echo "$progname: *** $1" 1>&2
  echo "$progname: *** Stop." 1>&2
  func_exit 1
}

# func_readlink SYMLINK
# outputs the target of the given symlink.
if (type -p readlink) > /dev/null 2>&1; then
  func_readlink ()
  {
    # Use the readlink program from GNU coreutils.
    readlink "$1"
  }
else
  func_readlink ()
  {
    # Use two sed invocations. A single sed -n -e 's,^.* -> \(.*\)$,\1,p'
    # would do the wrong thing if the link target contains " -> ".
    LC_ALL=C ls -l "$1" | sed -e 's, -> ,#%%#,' | sed -n -e 's,^.*#%%#\(.*\)$,\1,p'
  }
fi

# Command-line option processing.
while test $# -gt 0; do
  case "$1" in
    --help | --hel | --he | --h )
      func_usage
      exit $? ;;
    --version | --versio | --versi | --vers | --ver | --ve | --v )
      func_version
      exit $? ;;
    -* )
      echo "posix-modules: unknown option $1" 1>&2
      echo "Try 'posix-modules --help' for more information." 1>&2
      exit 1 ;;
    * )
      echo "posix-modules: too many arguments" 1>&2
      echo "Try 'posix-modules --help' for more information." 1>&2
      exit 1 ;;
  esac
done

func_gnulib_dir
(
  # Get the header modules.
  LC_ALL=C grep -h '^Gnulib module: ' "$gnulib_dir"/doc/posix-headers/*.texi 2>/dev/null \
    | sed -e 's,^Gnulib module: ,,'
  # Get the function modules.
  LC_ALL=C grep -h '^Gnulib module: ' "$gnulib_dir"/doc/posix-functions/*.texi 2>/dev/null \
    | sed -e 's,^Gnulib module: ,,'
  # Then filter out the words "---", ",", "and", "or" and remove *-gnu modules.
) | sed -e 's/,/ /g' | LC_ALL=C sort | LC_ALL=C uniq \
  | { # Then filter out the words "---", "and", "or" and remove *-gnu modules.
      tr ' ' '\012' | sed -e '/^---$/d' -e '/^and$/d' -e '/^or$/d' -e '/-gnu$/d'
    } \
  | LC_ALL=C sort | LC_ALL=C uniq

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