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74 lines
2.6 KiB
Plaintext
74 lines
2.6 KiB
Plaintext
# readlink.m4 serial 15
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dnl Copyright (C) 2003, 2007, 2009-2020 Free Software Foundation, Inc.
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dnl This file is free software; the Free Software Foundation
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dnl gives unlimited permission to copy and/or distribute it,
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dnl with or without modifications, as long as this notice is preserved.
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AC_DEFUN([gl_FUNC_READLINK],
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[
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AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
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AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
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AC_CHECK_FUNCS_ONCE([readlink])
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if test $ac_cv_func_readlink = no; then
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HAVE_READLINK=0
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else
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AC_CACHE_CHECK([whether readlink signature is correct],
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[gl_cv_decl_readlink_works],
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[AC_COMPILE_IFELSE(
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[AC_LANG_PROGRAM(
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[[#include <unistd.h>
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/* Cause compilation failure if original declaration has wrong type. */
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ssize_t readlink (const char *, char *, size_t);]])],
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[gl_cv_decl_readlink_works=yes], [gl_cv_decl_readlink_works=no])])
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dnl Solaris 9 ignores trailing slash.
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dnl FreeBSD 7.2 dereferences only one level of links with trailing slash.
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AC_CACHE_CHECK([whether readlink handles trailing slash correctly],
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[gl_cv_func_readlink_works],
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[# We have readlink, so assume ln -s works.
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ln -s conftest.no-such conftest.link
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ln -s conftest.link conftest.lnk2
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AC_RUN_IFELSE(
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[AC_LANG_PROGRAM(
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[[#include <unistd.h>
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]], [[char buf[20];
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return readlink ("conftest.lnk2/", buf, sizeof buf) != -1;]])],
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[gl_cv_func_readlink_works=yes], [gl_cv_func_readlink_works=no],
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[case "$host_os" in
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# Guess yes on Linux systems.
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linux-* | linux) gl_cv_func_readlink_works="guessing yes" ;;
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# Guess yes on glibc systems.
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*-gnu* | gnu*) gl_cv_func_readlink_works="guessing yes" ;;
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# If we don't know, obey --enable-cross-guesses.
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*) gl_cv_func_readlink_works="$gl_cross_guess_normal" ;;
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esac
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])
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rm -f conftest.link conftest.lnk2])
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case "$gl_cv_func_readlink_works" in
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*yes)
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if test "$gl_cv_decl_readlink_works" != yes; then
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REPLACE_READLINK=1
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fi
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;;
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*)
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AC_DEFINE([READLINK_TRAILING_SLASH_BUG], [1], [Define to 1 if readlink
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fails to recognize a trailing slash.])
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REPLACE_READLINK=1
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;;
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esac
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fi
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])
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# Like gl_FUNC_READLINK, except prepare for separate compilation
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# (no REPLACE_READLINK, no AC_LIBOBJ).
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AC_DEFUN([gl_FUNC_READLINK_SEPARATE],
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[
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AC_CHECK_FUNCS_ONCE([readlink])
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gl_PREREQ_READLINK
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])
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# Prerequisites of lib/readlink.c.
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AC_DEFUN([gl_PREREQ_READLINK],
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[
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:
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])
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