mirror of
https://github.com/coreutils/coreutils.git
synced 2024-12-02 06:23:51 +08:00
65 lines
1.7 KiB
Plaintext
65 lines
1.7 KiB
Plaintext
#serial 1
|
|
dnl Run a program to determine whether whether link(2) follows symlinks.
|
|
dnl Set LINK_FOLLOWS_SYMLINKS accordingly.
|
|
|
|
AC_DEFUN(jm_AC_FUNC_LINK_FOLLOWS_SYMLINK,
|
|
[dnl
|
|
AC_CACHE_CHECK([whether link(2) follows symlinks],
|
|
jm_ac_cv_func_link_follows_symlink,
|
|
[
|
|
dnl poor-man's AC_REQUIRE: FIXME: repair this once autoconf-3 provides
|
|
dnl the appropriate framework.
|
|
test -z "$ac_cv_header_unistd_h" \
|
|
&& AC_CHECK_HEADERS(unistd.h)
|
|
|
|
# Create a regular file.
|
|
echo > conftest.file
|
|
AC_TRY_RUN(
|
|
[
|
|
# include <sys/types.h>
|
|
# include <sys/stat.h>
|
|
# ifdef HAVE_UNISTD_H
|
|
# include <unistd.h>
|
|
# endif
|
|
|
|
# define SAME_INODE(Stat_buf_1, Stat_buf_2) \
|
|
((Stat_buf_1).st_ino == (Stat_buf_2).st_ino \
|
|
&& (Stat_buf_1).st_dev == (Stat_buf_2).st_dev)
|
|
|
|
int
|
|
main ()
|
|
{
|
|
const char *file = "conftest.file";
|
|
const char *sym = "conftest.sym";
|
|
const char *hard = "conftest.hard";
|
|
struct stat sb_file, sb_hard;
|
|
|
|
/* Create a symlink to the regular file. */
|
|
if (symlink (file, sym))
|
|
abort ();
|
|
|
|
/* Create a hard link to that symlink. */
|
|
if (link (sym, hard))
|
|
abort ();
|
|
|
|
if (lstat (hard, &sb_hard))
|
|
abort ();
|
|
if (lstat (file, &sb_file))
|
|
abort ();
|
|
|
|
/* If the dev/inode of hard and file are the same, then
|
|
the link call followed the symlink. */
|
|
return SAME_INODE (sb_hard, sb_file) ? 0 : 1;
|
|
}
|
|
],
|
|
jm_ac_cv_func_link_follows_symlink=yes,
|
|
jm_ac_cv_func_link_follows_symlink=no,
|
|
jm_ac_cv_func_link_follows_symlink=yes dnl We're cross compiling.
|
|
)
|
|
])
|
|
if test $jm_ac_cv_func_link_follows_symlink = yes; then
|
|
AC_DEFINE(LINK_FOLLOWS_SYMLINKS, 1,
|
|
[Define if `link(2)' dereferences symbolic links.])
|
|
fi
|
|
])
|