meta: add internal common library

common/include/ivy/line-source.h

@@ -0,0 +1,22 @@
+#ifndef IVY_COMMON_LINE_SOURCE_H_
+#define IVY_COMMON_LINE_SOURCE_H_
+
+#include <stddef.h>
+
+enum ivy_line_source_status {
+	IVY_LS_OK = 0,
+	IVY_LS_EOF,
+	IVY_LS_ERR_IOERR,
+	IVY_LS_ERR_NOSYS,
+};
+
+struct ivy_line_source {
+	enum ivy_line_source_status (*s_readline)(
+		struct ivy_line_source *, char *, size_t, size_t *, const char *);
+};
+
+extern enum ivy_line_source_status ivy_line_source_readline(
+	struct ivy_line_source *src, char *buf, size_t count, size_t *nr_read,
+	const char *prompt);
+
+#endif