openat: work around AIX 7.1 fstatat bug

[gnulib.git] / lib / ftruncate.c

diff --git a/lib/ftruncate.c b/lib/ftruncate.c
index 4f6aaa9..33b69d8 100644 (file)
--- a/lib/ftruncate.c
+++ b/lib/ftruncate.c
@@ -1,16 +1,10 @@
 /* ftruncate emulations that work on some System V's.
    This file is in the public domain.  */
 
-#ifdef HAVE_CONFIG_H
-#if defined (CONFIG_BROKETS)
-/* We use <config.h> instead of "config.h" so that a compilation
-   using -I. -I$srcdir will use ./config.h rather than $srcdir/config.h
-   (which it would do because it found this file in $srcdir).  */
 #include <config.h>
-#else
-#include "config.h"
-#endif
-#endif
+
+/* Specification.  */
+#include <unistd.h>
 
 #include <sys/types.h>
 #include <fcntl.h>
@@ -18,26 +12,21 @@
 #ifdef F_CHSIZE
 
 int
-ftruncate (fd, length)
-     int fd;
-     off_t length;
+ftruncate (int fd, off_t length)
 {
   return fcntl (fd, F_CHSIZE, length);
 }
 
 #else /* not F_CHSIZE */
-#ifdef F_FREESP
+# ifdef F_FREESP
 
 /* By William Kucharski <kucharsk@netcom.com>.  */
 
-#include <sys/stat.h>
-#include <errno.h>
-#include <unistd.h>
+#  include <sys/stat.h>
+#  include <errno.h>
 
 int
-ftruncate (fd, length)
-     int fd;
-     off_t length;
+ftruncate (int fd, off_t length)
 {
   struct flock fl;
   struct stat filebuf;
@@ -49,11 +38,11 @@ ftruncate (fd, length)
     {
       /* Extend file length. */
       if (lseek (fd, (length - 1), SEEK_SET) < 0)
-       return -1;
+        return -1;
 
       /* Write a "0" byte. */
       if (write (fd, "", 1) != 1)
-       return -1;
+        return -1;
     }
   else
     {
@@ -63,46 +52,39 @@ ftruncate (fd, length)
       fl.l_whence = 0;
       fl.l_len = 0;
       fl.l_start = length;
-      fl.l_type = F_WRLCK;     /* write lock on file space */
+      fl.l_type = F_WRLCK;      /* write lock on file space */
 
       /* This relies on the *undocumented* F_FREESP argument to fcntl,
-        which truncates the file so that it ends at the position
-        indicated by fl.l_start.  Will minor miracles never cease?  */
+         which truncates the file so that it ends at the position
+         indicated by fl.l_start.  Will minor miracles never cease?  */
 
       if (fcntl (fd, F_FREESP, &fl) < 0)
-       return -1;
+        return -1;
     }
 
   return 0;
 }
 
-#else /* not F_CHSIZE nor F_FREESP */
-#ifdef HAVE_CHSIZE
+# else /* not F_CHSIZE nor F_FREESP */
+#  if HAVE_CHSIZE                      /* native Windows, e.g. mingw */
 
 int
-ftruncate (fd, length)
-     int fd;
-     off_t length;
+ftruncate (int fd, off_t length)
 {
   return chsize (fd, length);
 }
 
-#else /* not F_CHSIZE nor F_FREESP nor HAVE_CHSIZE */
+#  else /* not F_CHSIZE nor F_FREESP nor HAVE_CHSIZE */
 
-#include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
+#   include <errno.h>
 
 int
-ftruncate (fd, length)
-     int fd;
-     off_t length;
+ftruncate (int fd, off_t length)
 {
   errno = EIO;
   return -1;
 }
 
-#endif /* not HAVE_CHSIZE */
-#endif /* not F_FREESP */
+#  endif /* not HAVE_CHSIZE */
+# endif /* not F_FREESP */
 #endif /* not F_CHSIZE */