/* ftruncate emulations that work on some System V's.
This file is in the public domain. */
-#ifdef HAVE_CONFIG_H
#include <config.h>
-#endif
+
+/* Specification. */
+#include <unistd.h>
#include <sys/types.h>
#include <fcntl.h>
#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>
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif
+# 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;
{
/* 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
{
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 */