# ===========================================================================

#      http://www.gnu.org/software/autoconf-archive/ax_lib_readline.html

# ===========================================================================

#

# SYNOPSIS

#

#   AX_LIB_READLINE

#

# DESCRIPTION

#

#   Searches for a readline compatible library. If found, defines

#   `HAVE_LIBREADLINE'. If the found library has the `add_history' function,

#   sets also `HAVE_READLINE_HISTORY'. Also checks for the locations of the

#   necessary include files and sets `HAVE_READLINE_H' or

#   `HAVE_READLINE_READLINE_H' and `HAVE_READLINE_HISTORY_H' or

#   'HAVE_HISTORY_H' if the corresponding include files exists.

#

#   The libraries that may be readline compatible are `libedit',

#   `libeditline' and `libreadline'. Sometimes we need to link a termcap

#   library for readline to work, this macro tests these cases too by trying

#   to link with `libtermcap', `libcurses' or `libncurses' before giving up.

#

#   Here is an example of how to use the information provided by this macro

#   to perform the necessary includes or declarations in a C file:

#

#     #ifdef HAVE_LIBREADLINE

#     #  if defined(HAVE_READLINE_READLINE_H)

#     #    include <readline/readline.h>

#     #  elif defined(HAVE_READLINE_H)

#     #    include <readline.h>

#     #  else /* !defined(HAVE_READLINE_H) */

#     extern char *readline ();

#     #  endif /* !defined(HAVE_READLINE_H) */

#     char *cmdline = NULL;

#     #else /* !defined(HAVE_READLINE_READLINE_H) */

#       /* no readline */

#     #endif /* HAVE_LIBREADLINE */

#

#     #ifdef HAVE_READLINE_HISTORY

#     #  if defined(HAVE_READLINE_HISTORY_H)

#     #    include <readline/history.h>

#     #  elif defined(HAVE_HISTORY_H)

#     #    include <history.h>

#     #  else /* !defined(HAVE_HISTORY_H) */

#     extern void add_history ();

#     extern int write_history ();

#     extern int read_history ();

#     #  endif /* defined(HAVE_READLINE_HISTORY_H) */

#       /* no history */

#     #endif /* HAVE_READLINE_HISTORY */

#

# LICENSE

#

#   Copyright (c) 2008 Ville Laurikari <vl@iki.fi>

#

#   Copying and distribution of this file, with or without modification, are

#   permitted in any medium without royalty provided the copyright notice

#   and this notice are preserved. This file is offered as-is, without any

#   warranty.

#serial 6

AU_ALIAS([VL_LIB_READLINE], [AX_LIB_READLINE])

AC_DEFUN([AX_LIB_READLINE], [

  AC_CACHE_CHECK([for a readline compatible library],

                 ax_cv_lib_readline, [

    ORIG_LIBS="$LIBS"

    for readline_lib in readline edit editline; do

      # prefer ncurses since we use it for nmtui too

      for termcap_lib in "" ncurses termcap curses; do

        if test -z "$termcap_lib"; then

          TRY_LIB="-l$readline_lib"

        else

          TRY_LIB="-l$readline_lib -l$termcap_lib"

        fi

        LIBS="$ORIG_LIBS $TRY_LIB"

        AC_TRY_LINK_FUNC(readline, ax_cv_lib_readline="$TRY_LIB")

        if test -n "$ax_cv_lib_readline"; then

          break

        fi

      done

      if test -n "$ax_cv_lib_readline"; then

        break

      fi

    done

    LIBS="$ORIG_LIBS"

  ])

  if test -z "$ax_cv_lib_readline"; then

    AC_MSG_ERROR([readline library with terminfo support is required (one of readline, edit, or editline, AND one of ncurses, curses, or termcap)])

  fi

  ORIG_LIBS="$LIBS"

  LIBS="$LIBS $ax_cv_lib_readline"

  AC_CHECK_HEADERS(readline.h readline/readline.h)

  # Check history

  AC_CACHE_CHECK([whether readline supports history],

                 ax_cv_lib_readline_history, [

    ax_cv_lib_readline_history="no"

    AC_TRY_LINK_FUNC(add_history, ax_cv_lib_readline_history="yes")

  ])

  if test "$ax_cv_lib_readline_history" != "yes"; then

    AC_MSG_ERROR(readline history support is required)

  fi

  AC_CHECK_HEADERS(history.h readline/history.h)

  # check rl_echo_signal_char()

  AC_CACHE_CHECK([whether readline supports rl_echo_signal_char()],

                 ax_cv_lib_readline_echo_signal_char, [

    ax_cv_lib_readline_echo_signal_char="no"

    AC_TRY_LINK_FUNC(rl_echo_signal_char, ax_cv_lib_readline_echo_signal_char="yes")

  ])

  if test "$ax_cv_lib_readline_echo_signal_char" != "yes"; then

    AC_MSG_ERROR(rl_echo_signal_char() is required (install readline6?))

  fi

  LIBS="$ORIG_LIBS"

  READLINE_LIBS="$ax_cv_lib_readline"

  AC_SUBST(READLINE_LIBS)

])dnl