Added generic line-buffering code (a la stdio)

src/include/gpxe/linebuf.h

@@ -0,0 +1,37 @@
+#ifndef _GPXE_LINEBUF_H
+#define _GPXE_LINEBUF_H
+
+/** @file
+ *
+ * Line buffering
+ *
+ */
+
+#include <stdint.h>
+#include <stddef.h>
+
+/** A line buffer */
+struct line_buffer {
+	/** Current data in the buffer */
+	char *data;
+	/** Length of current data */
+	size_t len;
+	/** Bitmask of terminating characters to skip over */
+	unsigned int skip_terminators;
+};
+
+/**
+ * Retrieve buffered-up line
+ *
+ * @v linebuf		Line buffer
+ * @ret line		Buffered line, or NULL if no line present
+ */
+static inline char * buffered_line ( struct line_buffer *linebuf ) {
+	return linebuf->data;
+}
+
+extern int line_buffer ( struct line_buffer *linebuf, const char *data,
+			 size_t len );
+extern void empty_line_buffer ( struct line_buffer *linebuf );
+
+#endif /* _GPXE_LINEBUF_H */