1 # readlink.m4 serial 13
2 dnl Copyright (C) 2003, 2007, 2009-2017 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 AC_DEFUN([gl_FUNC_READLINK],
9 AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
10 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
11 AC_CHECK_FUNCS_ONCE([readlink])
12 if test $ac_cv_func_readlink = no; then
15 AC_CACHE_CHECK([whether readlink signature is correct],
16 [gl_cv_decl_readlink_works],
20 /* Cause compilation failure if original declaration has wrong type. */
21 ssize_t readlink (const char *, char *, size_t);]])],
22 [gl_cv_decl_readlink_works=yes], [gl_cv_decl_readlink_works=no])])
23 dnl Solaris 9 ignores trailing slash.
24 dnl FreeBSD 7.2 dereferences only one level of links with trailing slash.
25 AC_CACHE_CHECK([whether readlink handles trailing slash correctly],
26 [gl_cv_func_readlink_works],
27 [# We have readlink, so assume ln -s works.
28 ln -s conftest.no-such conftest.link
29 ln -s conftest.link conftest.lnk2
34 return readlink ("conftest.lnk2/", buf, sizeof buf) != -1;]])],
35 [gl_cv_func_readlink_works=yes], [gl_cv_func_readlink_works=no],
37 # Guess yes on glibc systems.
38 *-gnu* | gnu*) gl_cv_func_readlink_works="guessing yes" ;;
39 # If we don't know, assume the worst.
40 *) gl_cv_func_readlink_works="guessing no" ;;
43 rm -f conftest.link conftest.lnk2])
44 case "$gl_cv_func_readlink_works" in
46 if test "$gl_cv_decl_readlink_works" != yes; then
51 AC_DEFINE([READLINK_TRAILING_SLASH_BUG], [1], [Define to 1 if readlink
52 fails to recognize a trailing slash.])
59 # Like gl_FUNC_READLINK, except prepare for separate compilation
60 # (no REPLACE_READLINK, no AC_LIBOBJ).
61 AC_DEFUN([gl_FUNC_READLINK_SEPARATE],
63 AC_CHECK_FUNCS_ONCE([readlink])
67 # Prerequisites of lib/readlink.c.
68 AC_DEFUN([gl_PREREQ_READLINK],