dnl Process this file with autoconf to produce a configure script.
AC_INIT(forwback.c)
AC_CONFIG_HEADER(defines.h)

dnl Checks for programs.
AC_PROG_CC
AC_ISC_POSIX
AC_PROG_GCC_TRADITIONAL
AC_PROG_INSTALL

dnl Checks for libraries.
AC_CHECK_LIB(ncurses, initscr, [have_ncurses=yes], [have_ncurses=no])
AC_CHECK_LIB(curses, initscr, [have_curses=yes], [have_curses=no])
AC_CHECK_LIB(termcap, tgetent, [have_termcap=yes], [have_termcap=no])
AC_CHECK_LIB(termlib, tgetent, [have_termlib=yes], [have_termlib=no])
dnl Regular expressions (regcmp) are in -lgen on Solaris 2,
dnl and in -lintl on SCO Unix.
AC_CHECK_LIB(gen, regcmp)
AC_CHECK_LIB(intl, regcmp)
AC_CHECK_LIB(PW, regcmp)

dnl Checks for terminal libraries
dnl Solaris has curses & termcap, but they need libucb
dnl which is broken, so we use termlib.

AC_MSG_CHECKING(for working terminal libraries)
TERMLIBS=
if test $have_ncurses = yes; then
  TERMLIBS="$TERMLIBS -lncurses"
  dnl Don't use -ltermcap with -lncurses (Linux doesn't like it).
else
  if test $have_curses = yes; then
    TERMLIBS="$TERMLIBS -lcurses"
  fi
  if test $have_termcap = yes; then
    TERMLIBS="$TERMLIBS -ltermcap"
  fi
fi

SAVE_LIBS=$LIBS
LIBS="$LIBS $TERMLIBS"
AC_TRY_LINK(, [tgetent(0); tgetflag(0); tgetnum(0); tgetstr(0);],
  [termok=yes], [termok=no])
if test $termok = yes; then
  AC_MSG_RESULT(using $TERMLIBS)
else
  LIBS="$SAVE_LIBS"
  if test $have_termlib = yes; then
    LIBS="$LIBS -ltermlib"
    AC_MSG_RESULT(using -ltermlib)
  else
    AC_MSG_RESULT(Cannot find terminal libraries - configure failed)
    exit 1
  fi
fi

dnl Checks for header files.
AC_HEADER_STDC
AC_CHECK_HEADERS(ctype.h errno.h fcntl.h limits.h stdio.h string.h termcap.h termio.h termios.h time.h unistd.h values.h sys/ioctl.h sys/stream.h sys/ptem.h)

dnl Checks for identifiers.
AC_TYPE_OFF_T
AC_MSG_CHECKING(for void)
AC_TRY_COMPILE(, [void *foo = 0;], 
  [AC_MSG_RESULT(yes); AC_DEFINE(HAVE_VOID)], [AC_MSG_RESULT(no)])
AC_MSG_CHECKING(for const)
AC_TRY_COMPILE(, [const int foo = 0;], 
  [AC_MSG_RESULT(yes); AC_DEFINE(HAVE_CONST)], [AC_MSG_RESULT(no)])
AC_MSG_CHECKING(for time_t)
AC_TRY_COMPILE([#include <time.h>], [time_t t = 0;],
  [AC_MSG_RESULT(yes); AC_DEFINE(HAVE_TIME_T)], [AC_MSG_RESULT(no)])

dnl Checks for functions and external variables.
AC_TYPE_SIGNAL
AC_CHECK_FUNCS(memcpy popen _setjmp sigsetmask stat strchr system)

dnl Some systems have termios.h but not the corresponding functions.
AC_CHECK_FUNC(tcgetattr, AC_DEFINE(HAVE_TERMIOS_FUNCS))

AC_MSG_CHECKING(for fileno)
AC_TRY_LINK([
#if HAVE_STDIO_H
#include <stdio.h>
#endif], [static int x; x = fileno(stdin);],
  [AC_MSG_RESULT(yes); AC_DEFINE(HAVE_FILENO)], [AC_MSG_RESULT(no)])

AC_MSG_CHECKING(for strerror)
AC_TRY_LINK([
#if HAVE_STDIO_H
#include <stdio.h>
#endif
#if HAVE_STRING_H
#include <string.h>
#endif
#if HAVE_ERRNO_H
#include <errno.h>
#endif], [static char *x; x = strerror(0);],
  [AC_MSG_RESULT(yes); AC_DEFINE(HAVE_STRERROR)], [AC_MSG_RESULT(no)])

AC_MSG_CHECKING(for sys_errlist)
AC_TRY_LINK(, [extern char *sys_errlist[]; static char **x; x = sys_errlist;], 
  [AC_MSG_RESULT(yes); AC_DEFINE(HAVE_SYS_ERRLIST)], [AC_MSG_RESULT(no)])

have_errno=no
AC_MSG_CHECKING(for errno)
AC_TRY_LINK([
#if HAVE_ERRNO_H
#include <errno.h>
#endif], [static int x; x = errno;], 
  [AC_MSG_RESULT(yes - in errno.h); AC_DEFINE(HAVE_ERRNO) have_errno=yes])
if test $have_errno = no; then
AC_TRY_LINK([
#if HAVE_ERRNO_H
#include <errno.h>
#endif], [extern int errno; static int x; x = errno;], 
  [AC_MSG_RESULT(yes - must define); AC_DEFINE(HAVE_ERRNO) AC_DEFINE(MUST_DEFINE_ERRNO)],
  [AC_MSG_RESULT(no)])
fi

AC_MSG_CHECKING(for locale)
AC_TRY_LINK([#include <locale.h>
#include <ctype.h>], [setlocale(LC_CTYPE,""); isprint(0); iscntrl(0);],
  [AC_MSG_RESULT(yes); AC_DEFINE(HAVE_LOCALE)], [AC_MSG_RESULT(no)])
AC_MSG_CHECKING(for ctype functions)
AC_TRY_LINK([
#if HAVE_CTYPE_H
#include <ctype.h>
#endif], [static int x; x = isupper(x); x = tolower(x); x = toupper(x);],
  [AC_MSG_RESULT(yes); AC_DEFINE(HAVE_UPPER_LOWER)], [AC_MSG_RESULT(no)])

dnl Checks for external variable ospeed in the termcap library.
have_ospeed=no
AC_MSG_CHECKING(termcap for ospeed)
AC_TRY_LINK([
#include <sys/types.h>
#if HAVE_TERMIOS_H
#include <termios.h>
#endif
#if HAVE_TERMCAP_H
#include <termcap.h>
#endif], [ospeed = 0;],
[AC_MSG_RESULT(yes - in termcap.h); AC_DEFINE(HAVE_OSPEED) have_ospeed=yes])
if test $have_ospeed = no; then
AC_TRY_LINK(, [extern short ospeed; ospeed = 0;], 
  [AC_MSG_RESULT(yes - must define); AC_DEFINE(HAVE_OSPEED) AC_DEFINE(MUST_DEFINE_OSPEED)],
  [AC_MSG_RESULT(no)])
fi

dnl Checks for regular expression functions.
have_regex=no
have_posix_regex=unknown
AC_MSG_CHECKING(for regcomp)
dnl Some versions of Solaris have a regcomp() function, but it doesn't work!
dnl So we run a test program.  If we're cross-compiling, do it the old way.
AC_TRY_RUN([
#include <sys/types.h>
#include <regex.h>
main() { regex_t r; regmatch_t rm;
if (regcomp(&r, "abc", 0)) exit(1);
if (regexec(&r, "xabcy", 1, &rm, 0)) exit(1);
exit(0); }],
  have_posix_regex=yes, have_posix_regex=no, have_posix_regex=unknown)
if test $have_posix_regex = yes; then
  AC_MSG_RESULT(using POSIX regcomp)
  AC_DEFINE(HAVE_POSIX_REGCOMP)
  have_regex=yes
elif test $have_posix_regex = unknown; then
  AC_TRY_LINK([
#include <sys/types.h>
#include <regex.h>],
  [regex_t *r; regfree(r);],
  AC_MSG_RESULT(using POSIX regcomp)
  AC_DEFINE(HAVE_POSIX_REGCOMP) have_regex=yes)
else
  AC_MSG_RESULT(no)
fi
if test $have_regex = no; then
AC_CHECK_FUNC(regcmp, 
AC_MSG_RESULT(using regcmp); AC_DEFINE(HAVE_REGCMP) have_regex=yes)
fi
if test $have_regex = no; then
AC_TRY_LINK([
#include "regexp.h"], [regcomp("");],
AC_MSG_RESULT(using V8 regcomp); AC_DEFINE(HAVE_V8_REGCOMP) have_regex=yes)
fi
if test $have_regex = no && test -f ${srcdir}/regex.c; then
AC_MSG_RESULT(using POSIX regcomp -- local source); AC_DEFINE(HAVE_POSIX_REGCOMP) REGEX_O='regex.$(O)' AC_SUBST(REGEX_O) have_regex=yes
fi
if test $have_regex = no && test -f ${srcdir}/regexp.c; then
AC_MSG_RESULT(using V8 regcomp -- local source); AC_DEFINE(HAVE_V8_REGCOMP) REGEX_O='regexp.$(O)' AC_SUBST(REGEX_O) have_regex=yes
fi
if test $have_regex = no; then
AC_MSG_RESULT(using re_comp); AC_CHECK_FUNC(re_comp, AC_DEFINE(HAVE_RE_COMP) have_regex=yes)
fi
if test $have_regex = no; then
AC_MSG_RESULT(cannot find regular expression library); AC_DEFINE(NO_REGEX)
fi

AC_OUTPUT(Makefile)