-/* ftruncate emulations that work on some System V's.
+/* ftruncate emulations for native Windows.
This file is in the public domain. */
-#if HAVE_CONFIG_H
-# include <config.h>
-#endif
-
-#include <sys/types.h>
-#include <fcntl.h>
+#include <config.h>
-#ifdef F_CHSIZE
-
-int
-ftruncate (int fd, off_t length)
-{
- return fcntl (fd, F_CHSIZE, length);
-}
+/* Specification. */
+#include <unistd.h>
-#else /* not F_CHSIZE */
-# ifdef F_FREESP
+#if HAVE_CHSIZE
-/* By William Kucharski <kucharsk@netcom.com>. */
+# include <errno.h>
+# include <io.h>
-# include <sys/stat.h>
-# include <errno.h>
-# if HAVE_UNISTD_H
-# include <unistd.h>
-# endif
-
-int
-ftruncate (int fd, off_t length)
+# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+# include "msvc-inval.h"
+static inline int
+chsize_nothrow (int fd, long length)
{
- struct flock fl;
- struct stat filebuf;
+ int result;
- if (fstat (fd, &filebuf) < 0)
- return -1;
-
- if (filebuf.st_size < length)
+ TRY_MSVC_INVAL
{
- /* Extend file length. */
- if (lseek (fd, (length - 1), SEEK_SET) < 0)
- return -1;
-
- /* Write a "0" byte. */
- if (write (fd, "", 1) != 1)
- return -1;
+ result = chsize (fd, length);
}
- else
+ CATCH_MSVC_INVAL
{
-
- /* Truncate length. */
-
- fl.l_whence = 0;
- fl.l_len = 0;
- fl.l_start = length;
- 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? */
-
- if (fcntl (fd, F_FREESP, &fl) < 0)
- return -1;
+ result = -1;
+ errno = EBADF;
}
+ DONE_MSVC_INVAL;
- return 0;
+ return result;
}
-
-# else /* not F_CHSIZE nor F_FREESP */
-# if HAVE_CHSIZE
+# define chsize chsize_nothrow
+# endif
int
ftruncate (int fd, off_t length)
return chsize (fd, length);
}
-# else /* not F_CHSIZE nor F_FREESP nor HAVE_CHSIZE */
-
-# include <errno.h>
-
-int
-ftruncate (int fd, off_t length)
-{
- errno = EIO;
- return -1;
-}
-
-# endif /* not HAVE_CHSIZE */
-# endif /* not F_FREESP */
-#endif /* not F_CHSIZE */
+#endif