New test mode that allows run_parts to fail silently if the directory

[oweals/busybox.git] / libbb / copy_file_chunk.c

diff --git a/libbb/copy_file_chunk.c b/libbb/copy_file_chunk.c
index e9663c3542e5e12bf24cfe7e7adaddff7d6df3cd..63d2ab1737389086e1616863bd22a51c0d637509 100644 (file)
--- a/libbb/copy_file_chunk.c
+++ b/libbb/copy_file_chunk.c
@@ -2,65 +2,69 @@
 /*
  * Utility routines.
  *
- * Copyright (C) tons of folks.  Tracking down who wrote what
- * isn't something I'm going to worry about...  If you wrote something
- * here, please feel free to acknowledge your work.
+ * Copyright (C) many different people.  If you wrote this, please
+ * acknowledge your work.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * Based in part on code from sash, Copyright (c) 1999 by David I. Bell 
- * Permission has been granted to redistribute this code under the GPL.
- *
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ * USA
  */
 
 #include <stdio.h>
 #include <sys/stat.h>
 #include "libbb.h"
 
-/*
- * Copy chunksize bytes between two file descriptors
- *
- * unsigned long is used so that if -1 is passed as chunksize it will read as
- * much as possible, and it will work with off_t or off64_t
- */
+/* Copy CHUNKSIZE bytes (or until EOF if CHUNKSIZE equals -1) from SRC_FILE
+ * to DST_FILE.  */
 extern int copy_file_chunk(FILE *src_file, FILE *dst_file, unsigned long long chunksize)
 {
-       off_t size, amount_written;
-       char buffer[BUFSIZ]; /* BUFSIZ is declared in stdio.h */
-       
-       while (chunksize > 0) {
-               if (chunksize > BUFSIZ) {
+       size_t nread, nwritten, size;
+       char buffer[BUFSIZ];
+
+       while (chunksize != 0) {
+               if (chunksize > BUFSIZ)
                        size = BUFSIZ;
-               } else {
+               else
                        size = chunksize;
+
+               nread = fread (buffer, 1, size, src_file);
+
+               if (nread != size && ferror (src_file)) {
+                       perror_msg ("read");
+                       return -1;
+               } else if (nread == 0) {
+                       if (chunksize != -1) {
+                               error_msg ("Unable to read all data");
+                               return -1;
+                       }
+
+                       return 0;
                }
-               amount_written = fwrite(buffer, 1, fread(buffer, 1, size, src_file), dst_file);
-               if (amount_written != size) {
-                       error_msg("Couldnt write correct amount");
-                       return(FALSE);
+
+               nwritten = fwrite (buffer, 1, nread, dst_file);
+
+               if (nwritten != nread) {
+                       if (ferror (dst_file))
+                               perror_msg ("write");
+                       else
+                               error_msg ("Unable to write all data");
+                       return -1;
                }
-               chunksize -= amount_written;
+
+               if (chunksize != -1)
+                       chunksize -= nwritten;
        }
-       return (TRUE);
-}
 
-/* END CODE */
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/
+       return 0;
+}