'trap' portability trapped me...

[gnulib.git] / lib / utimens.c

diff --git a/lib/utimens.c b/lib/utimens.c
index 9f1a0e1..8d8bef4 100644 (file)
--- a/lib/utimens.c
+++ b/lib/utimens.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2003 Free Software Foundation, Inc.
+/* Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the
@@ -12,7 +12,7 @@
 
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software Foundation,
-   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
 /* Written by Paul Eggert.  */
 
@@ -24,6 +24,10 @@
 
 #include "utimens.h"
 
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
 #if HAVE_UTIME_H
 # include <utime.h>
 #endif
@@ -38,26 +42,123 @@ struct utimbuf
 };
 #endif
 
-/* Set the access and modification time stamps of FILE to be
-   TIMESPEC[0] and TIMESPEC[1], respectively.  */
+/* Some systems don't have ENOSYS.  */
+#ifndef ENOSYS
+# ifdef ENOTSUP
+#  define ENOSYS ENOTSUP
+# else
+/* Some systems don't have ENOTSUP either.  */
+#  define ENOSYS EINVAL
+# endif
+#endif
+
+#if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
+# define __attribute__(x)
+#endif
+
+#ifndef ATTRIBUTE_UNUSED
+# define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
+#endif
+
+/* Set the access and modification time stamps of FD (a.k.a. FILE) to be
+   TIMESPEC[0] and TIMESPEC[1], respectively.
+   FD must be either negative -- in which case it is ignored --
+   or a file descriptor that is open on FILE.
+   If FD is nonnegative, then FILE can be NULL, which means
+   use just futimes (or equivalent) instead of utimes (or equivalent),
+   and fail if on an old system without futimes (or equivalent).
+   If TIMESPEC is null, set the time stamps to the current time.
+   Return 0 on success, -1 (setting errno) on failure.  */
 
 int
-utimens (char const *file, struct timespec const timespec[2])
+futimens (int fd ATTRIBUTE_UNUSED,
+         char const *file, struct timespec const timespec[2])
 {
   /* There's currently no interface to set file timestamps with
      nanosecond resolution, so do the best we can, discarding any
      fractional part of the timestamp.  */
-#if HAVE_WORKING_UTIMES
+#if HAVE_FUTIMESAT || HAVE_WORKING_UTIMES
   struct timeval timeval[2];
-  timeval[0].tv_sec = timespec[0].tv_sec;
-  timeval[0].tv_usec = timespec[0].tv_nsec / 1000;
-  timeval[1].tv_sec = timespec[1].tv_sec;
-  timeval[1].tv_usec = timespec[1].tv_nsec / 1000;
-  return utimes (file, timeval);
-#else
-  struct utimbuf utimbuf;
-  utimbuf.actime = timespec[0].tv_sec;
-  utimbuf.modtime = timespec[1].tv_sec;
-  return utime (file, &utimbuf);
+  struct timeval const *t;
+  if (timespec)
+    {
+      timeval[0].tv_sec = timespec[0].tv_sec;
+      timeval[0].tv_usec = timespec[0].tv_nsec / 1000;
+      timeval[1].tv_sec = timespec[1].tv_sec;
+      timeval[1].tv_usec = timespec[1].tv_nsec / 1000;
+      t = timeval;
+    }
+  else
+    t = NULL;
+
+# if HAVE_FUTIMESAT
+  return fd < 0 ? futimesat (AT_FDCWD, file, t) : futimesat (fd, NULL, t);
+# elif HAVE_FUTIMES
+  if (0 <= fd)
+    {
+      if (futimes (fd, t) == 0)
+       return 0;
+
+      /* Don't worry about trying to speed things up by returning right
+        away here.  glibc futimes can incorrectly fail with errno ==
+        ENOENT if /proc isn't mounted.  Also, Mandrake 10.0 in high
+        security mode doesn't allow ordinary users to read /proc/self, so
+        glibc futimes incorrectly fails with errno == EACCES.  If futimes
+        fails with errno == EIO, EPERM, or EROFS, it's probably safe to
+        fail right away, but these cases are rare enough that they're not
+        worth optimizing, and who knows what other messed-up systems are
+        out there?  So play it safe and fall back on the code below.  */
+    }
+# endif
 #endif
+
+#if ! HAVE_FUTIMESAT
+
+  if (!file)
+    {
+# if ! (HAVE_WORKING_UTIMES && HAVE_FUTIMES)
+      errno = ENOSYS;
+# endif
+
+      /* Prefer EBADF to ENOSYS if both error numbers apply.  */
+      if (errno == ENOSYS)
+       {
+         int fd2 = dup (fd);
+         int dup_errno = errno;
+         if (0 <= fd2)
+           close (fd2);
+         errno = (fd2 < 0 && dup_errno == EBADF ? EBADF : ENOSYS);
+       }
+
+      return -1;
+    }
+
+# if HAVE_WORKING_UTIMES
+  return utimes (file, t);
+# else
+  {
+    struct utimbuf utimbuf;
+    struct utimbuf const *ut;
+    if (timespec)
+      {
+       utimbuf.actime = timespec[0].tv_sec;
+       utimbuf.modtime = timespec[1].tv_sec;
+       ut = &utimbuf;
+      }
+    else
+      ut = NULL;
+
+    return utime (file, ut);
+  }
+# endif
+
+#endif
+}
+
+/* Set the access and modification time stamps of FILE to be
+   TIMESPEC[0] and TIMESPEC[1], respectively.  */
+int
+utimens (char const *file, struct timespec const timespec[2])
+{
+  return futimens (-1, file, timespec);
 }