1 files changed, 157 insertions, 0 deletions
diff --git a/gnu/libexec/uucp/libunix/trunc.c b/gnu/libexec/uucp/libunix/trunc.c
new file mode 100644
index 000000000000..c93e82e39403
--- /dev/null
+++ b/gnu/libexec/uucp/libunix/trunc.c
@@ -0,0 +1,157 @@
+/* trunc.c
+   Truncate a file to zero length.  */
+
+#include "uucp.h"
+
+#include "uudefs.h"
+#include "sysdep.h"
+#include "system.h"
+
+#include <errno.h>
+
+#if HAVE_FCNTL_H
+#include <fcntl.h>
+#else
+#if HAVE_SYS_FILE_H
+#include <sys/file.h>
+#endif
+#endif
+
+#ifndef FD_CLOEXEC
+#define FD_CLOEXEC 1
+#endif
+
+#ifndef SEEK_SET
+#define SEEK_SET 0
+#endif
+
+/* External functions.  */
+#ifndef lseek
+extern off_t lseek ();
+#endif
+
+/* Truncate a file to zero length.  If this fails, it closes and
+   removes the file.  We support a number of different means of
+   truncation, which is probably a waste of time since this function
+   is currently only called when the 'f' protocol resends a file.  */
+
+#if HAVE_FTRUNCATE
+#undef HAVE_LTRUNC
+#define HAVE_LTRUNC 0
+#endif
+
+#if ! HAVE_FTRUNCATE && ! HAVE_LTRUNC
+#ifdef F_CHSIZE
+#define HAVE_F_CHSIZE 1
+#else /* ! defined (F_CHSIZE) */
+#ifdef F_FREESP
+#define HAVE_F_FREESP 1
+#endif /* defined (F_FREESP) */
+#endif /* ! defined (F_CHSIZE) */
+#endif /* ! HAVE_FTRUNCATE && ! HAVE_LTRUNC */
+
+openfile_t
+esysdep_truncate (e, zname)
+     openfile_t e;
+     const char *zname;
+{
+  int o;
+
+#if HAVE_FTRUNCATE || HAVE_LTRUNC || HAVE_F_CHSIZE || HAVE_F_FREESP
+  int itrunc;
+
+  if (! ffilerewind (e))
+    {
+      ulog (LOG_ERROR, "rewind: %s", strerror (errno));
+      (void) ffileclose (e);
+      (void) remove (zname);
+      return EFILECLOSED;
+    }
+
+#if USE_STDIO
+  o = fileno (e);
+#else
+  o = e;
+#endif
+
+#if HAVE_FTRUNCATE
+  itrunc = ftruncate (o, 0);
+#endif
+#if HAVE_LTRUNC
+  itrunc = ltrunc (o, (long) 0, SEEK_SET);
+#endif
+#if HAVE_F_CHSIZE
+  itrunc = fcntl (o, F_CHSIZE, (off_t) 0);
+#endif
+#if HAVE_F_FREESP
+  /* This selection is based on an implementation of ftruncate by
+     kucharsk@Solbourne.com (William Kucharski).  */
+  {
+    struct flock fl;
+
+    fl.l_whence = 0;
+    fl.l_len = 0;
+    fl.l_start = 0;
+    fl.l_type = F_WRLCK;
+
+    itrunc = fcntl (o, F_FREESP, &fl);
+  }
+#endif
+
+  if (itrunc != 0)
+    {
+#if HAVE_FTRUNCATE
+      ulog (LOG_ERROR, "ftruncate: %s", strerror (errno));
+#endif
+#ifdef HAVE_LTRUNC
+      ulog (LOG_ERROR, "ltrunc: %s", strerror (errno));
+#endif
+#ifdef HAVE_F_CHSIZE
+      ulog (LOG_ERROR, "fcntl (F_CHSIZE): %s", strerror (errno));
+#endif
+#ifdef HAVE_F_FREESP
+      ulog (LOG_ERROR, "fcntl (F_FREESP): %s", strerror (errno));
+#endif
+
+      (void) ffileclose (e);
+      (void) remove (zname);
+      return EFILECLOSED;
+    }
+
+  return e;
+#else /* ! (HAVE_FTRUNCATE || HAVE_LTRUNC || HAVE_F_CHSIZE || HAVE_F_FREESP) */
+  (void) ffileclose (e);
+  (void) remove (zname);
+
+  o = creat ((char *) zname, IPRIVATE_FILE_MODE);
+
+  if (o == -1)
+    {
+      ulog (LOG_ERROR, "creat (%s): %s", zname, strerror (errno));
+      return EFILECLOSED;
+    }
+
+  if (fcntl (o, F_SETFD, fcntl (o, F_GETFD, 0) | FD_CLOEXEC) < 0)
+    {
+      ulog (LOG_ERROR, "fcntl (FD_CLOEXEC): %s", strerror (errno));
+      (void) close (o);
+      return EFILECLOSED;
+    }
+
+#if USE_STDIO
+  e = fdopen (o, (char *) BINWRITE);
+
+  if (e == NULL)
+    {
+      ulog (LOG_ERROR, "fdopen (%s): %s", zname, strerror (errno));
+      (void) close (o);
+      (void) remove (zname);
+      return NULL;
+    }
+#else /* ! USE_STDIO */
+  e = o;
+#endif /* ! USE_STDIO */
+
+  return e;
+#endif /* ! (HAVE_FTRUNCATE || HAVE_LTRUNC || HAVE_F_CHSIZE || HAVE_F_FREESP) */
+}