1 files changed, 70 insertions, 0 deletions
diff --git a/libbb/copy_file_chunk.c b/libbb/copy_file_chunk.c
new file mode 100644
index 0000000..63d2ab1
--- /dev/null
+++ b/libbb/copy_file_chunk.c
@@ -0,0 +1,70 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * 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
+ * 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
+ */
+
+#include <stdio.h>
+#include <sys/stat.h>
+#include "libbb.h"
+
+/* 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)
+{
+	size_t nread, nwritten, size;
+	char buffer[BUFSIZ];
+
+	while (chunksize != 0) {
+		if (chunksize > BUFSIZ)
+			size = BUFSIZ;
+		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;
+		}
+
+		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;
+		}
+
+		if (chunksize != -1)
+			chunksize -= nwritten;
+	}
+
+	return 0;
+}