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authorJim Meyering <jim@meyering.net>1994-08-19 13:13:48 +0000
committerJim Meyering <jim@meyering.net>1994-08-19 13:13:48 +0000
commite50688802c032778d6711561807125b7841029b2 (patch)
tree4eacd65ad6d624e4ca50b6377101dcc599eabf92 /lib/ftruncate.c
parent1763c83a50b7dc34095c0991d4fe356a2e48991f (diff)
downloadcoreutils-e50688802c032778d6711561807125b7841029b2.tar.xz
.
Diffstat (limited to 'lib/ftruncate.c')
-rw-r--r--lib/ftruncate.c64
1 files changed, 51 insertions, 13 deletions
diff --git a/lib/ftruncate.c b/lib/ftruncate.c
index 17d263d51..04156b76d 100644
--- a/lib/ftruncate.c
+++ b/lib/ftruncate.c
@@ -1,10 +1,27 @@
/* ftruncate emulations that work on some System V's.
- This file is in the public domain. */
+ 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
#include <sys/types.h>
#include <fcntl.h>
+#include <errno.h>
+#ifndef STDC_HEADERS
+extern int errno;
+#endif
+
#ifdef F_CHSIZE
+
int
ftruncate (fd, length)
int fd;
@@ -12,14 +29,17 @@ ftruncate (fd, length)
{
return fcntl (fd, F_CHSIZE, length);
}
-#else
+
+#else /* not F_CHSIZE */
#ifdef F_FREESP
-/* The following function was written by
- kucharsk@Solbourne.com (William Kucharski) */
+
+/* By William Kucharski <kucharsk@netcom.com>. */
#include <sys/stat.h>
-#include <errno.h>
+
+#ifdef HAVE_UNISTD_H
#include <unistd.h>
+#endif
int
ftruncate (fd, length)
@@ -44,23 +64,28 @@ ftruncate (fd, length)
}
else
{
+
/* Truncate 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? */
- /* 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;
}
return 0;
}
-#else
+
+#else /* not F_CHSIZE nor F_FREESP */
+#ifdef HAVE_CHSIZE
+
int
ftruncate (fd, length)
int fd;
@@ -68,5 +93,18 @@ ftruncate (fd, length)
{
return chsize (fd, length);
}
-#endif
-#endif
+
+#else /* not F_CHSIZE nor F_FREESP nor HAVE_CHSIZE */
+
+int
+ftruncate (fd, length)
+ int fd;
+ off_t length;
+{
+ errno = EIO;
+ return -1;
+}
+
+#endif /* not HAVE_CHSIZE */
+#endif /* not F_FREESP */
+#endif /* not F_CHSIZE */