1 files changed, 86 insertions, 0 deletions
diff --git a/libbb/copyfd.c b/libbb/copyfd.c
new file mode 100644
index 0000000..c6b8866
--- /dev/null
+++ b/libbb/copyfd.c
@@ -0,0 +1,86 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * Copyright (C) 1999-2005 by Erik Andersen <andersen@codepoet.org>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "libbb.h"
+
+
+#if BUFSIZ < 4096
+#undef BUFSIZ
+#define BUFSIZ 4096
+#endif
+
+
+static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
+{
+	int status = -1;
+	off_t total = 0;
+	RESERVE_CONFIG_BUFFER(buffer, BUFSIZ);
+
+	if (src_fd < 0) goto out;
+
+	if (!size) {
+		size = BUFSIZ;
+		status = 1; /* copy until eof */
+	}
+
+	while (1) {
+		ssize_t rd;
+
+		rd = safe_read(src_fd, buffer, size > BUFSIZ ? BUFSIZ : size);
+
+		if (!rd) { /* eof - all done. */
+			status = 0;
+			break;
+		}
+		if (rd < 0) {
+			bb_perror_msg(bb_msg_read_error);
+			break;
+		}
+		/* dst_fd == -1 is a fake, else... */
+		if (dst_fd >= 0) {
+			ssize_t wr = full_write(dst_fd, buffer, rd);
+			if (wr < rd) {
+				bb_perror_msg(bb_msg_write_error);
+				break;
+			}
+		}
+		total += rd;
+		if (status < 0) {
+			size -= rd;
+			if (!size) {
+				status = 0;
+				break;
+			}
+		}
+	}
+
+out:
+	RELEASE_CONFIG_BUFFER(buffer);
+
+	return status ? -1 : total;
+}
+
+
+off_t bb_copyfd_size(int fd1, int fd2, off_t size)
+{
+	if (size) {
+		return bb_full_fd_action(fd1, fd2, size);
+	}
+	return 0;
+}
+
+off_t bb_copyfd_eof(int fd1, int fd2)
+{
+	return bb_full_fd_action(fd1, fd2, 0);
+}