.

1 files changed, 72 insertions, 0 deletions

diff --git a/read.c b/read.c
new file mode 100644
index 0000000..5906bc2
--- /dev/null
+++ b/read.c
@@ -0,0 +1,72 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+#include "libbb.h"
+
+ssize_t FAST_FUNC safe_read(int fd, void *buf, size_t count)
+{
+	ssize_t n;
+
+	do {
+		n = read(fd, buf, count);
+	} while (n < 0 && errno == EINTR);
+
+	return n;
+}
+
+/*
+ * Read all of the supplied buffer from a file.
+ * This does multiple reads as necessary.
+ * Returns the amount read, or -1 on an error.
+ * A short read is returned on an end of file.
+ */
+ssize_t FAST_FUNC full_read(int fd, void *buf, size_t len)
+{
+	ssize_t cc;
+	ssize_t total;
+
+	total = 0;
+
+	while (len) {
+		cc = safe_read(fd, buf, len);
+
+		if (cc < 0) {
+			if (total) {
+				/* we already have some! */
+				/* user can do another read to know the error code */
+				return total;
+			}
+			return cc; /* read() returns -1 on failure. */
+		}
+		if (cc == 0)
+			break;
+		buf = ((char *)buf) + cc;
+		total += cc;
+		len -= cc;
+	}
+
+	return total;
+}
+
+ssize_t FAST_FUNC read_close(int fd, void *buf, size_t size)
+{
+	/*int e;*/
+	size = full_read(fd, buf, size);
+	/*e = errno;*/
+	close(fd);
+	/*errno = e;*/
+	return size;
+}
+
+ssize_t FAST_FUNC open_read_close(const char *filename, void *buf, size_t size)
+{
+	int fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		return fd;
+	return read_close(fd, buf, size);
+}