wget/m4/mkstemp.m4

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#serial 26
# Copyright (C) 2001, 2003-2007, 2009-2019 Free Software Foundation, Inc.
# This file is free software; the Free Software Foundation
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.
# On some hosts (e.g., HP-UX 10.20, SunOS 4.1.4, Solaris 2.5.1), mkstemp has a
# silly limit that it can create no more than 26 files from a given template.
# Other systems lack mkstemp altogether.
# On OSF1/Tru64 V4.0F, the system-provided mkstemp function can create
# only 32 files per process.
# On some hosts, mkstemp creates files with mode 0666, which is a security
# problem and a violation of POSIX 2008.
# On systems like the above, arrange to use the replacement function.
AC_DEFUN([gl_FUNC_MKSTEMP],
[
AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
AC_CHECK_FUNCS_ONCE([mkstemp])
if test $ac_cv_func_mkstemp = yes; then
AC_CACHE_CHECK([for working mkstemp],
[gl_cv_func_working_mkstemp],
[
mkdir conftest.mkstemp
AC_RUN_IFELSE(
[AC_LANG_PROGRAM(
[AC_INCLUDES_DEFAULT],
[[int result = 0;
int i;
off_t large = (off_t) 4294967295u;
if (large < 0)
large = 2147483647;
umask (0);
for (i = 0; i < 70; i++)
{
char templ[] = "conftest.mkstemp/coXXXXXX";
int (*mkstemp_function) (char *) = mkstemp;
int fd = mkstemp_function (templ);
if (fd < 0)
result |= 1;
else
{
struct stat st;
if (lseek (fd, large, SEEK_SET) != large)
result |= 2;
if (fstat (fd, &st) < 0)
result |= 4;
else if (st.st_mode & 0077)
result |= 8;
if (close (fd))
result |= 16;
}
}
return result;]])],
[gl_cv_func_working_mkstemp=yes],
[gl_cv_func_working_mkstemp=no],
[case "$host_os" in
# Guess yes on glibc systems.
*-gnu* | gnu*) gl_cv_func_working_mkstemp="guessing yes" ;;
# Guess yes on musl systems.
*-musl*) gl_cv_func_working_mkstemp="guessing yes" ;;
# Guess no on native Windows.
mingw*) gl_cv_func_working_mkstemp="guessing no" ;;
# If we don't know, assume the worst.
*) gl_cv_func_working_mkstemp="guessing no" ;;
esac
])
rm -rf conftest.mkstemp
])
case "$gl_cv_func_working_mkstemp" in
*yes) ;;
*)
REPLACE_MKSTEMP=1
;;
esac
else
HAVE_MKSTEMP=0
fi
])
# Prerequisites of lib/mkstemp.c.
AC_DEFUN([gl_PREREQ_MKSTEMP],
[
])