Implement the \N'number' (numbered character) roff escape sequence.

Don't use it in new manuals, it is inherently non-portable, but we
need it for backward-compatibility with existing manuals, for example
in Xenocara driver pages.
ok kristaps@ jmc@ and tested by Matthieu Herrb (matthieu at openbsd dot org)

1 files changed, 23 insertions, 1 deletions

diff --git a/chars.c b/chars.c
index 5edf947a..18bd209b 100644
--- a/chars.c
+++ b/chars.c
@@ -1,6 +1,7 @@
-/*	$Id: chars.c,v 1.31 2011/01/02 10:10:57 kristaps Exp $ */
+/*	$Id: chars.c,v 1.32 2011/01/30 16:05:37 schwarze Exp $ */
 /*
  * Copyright (c) 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
+ * Copyright (c) 2011 Ingo Schwarze <schwarze@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -152,6 +153,27 @@ chars_res2cp(void *arg, const char *p, size_t sz)
 }
 
 
+/*
+ * Numbered character to literal character,
+ * represented as a null-terminated string for additional safety.
+ */
+const char *
+chars_num2char(const char *p, size_t sz)
+{
+	int		  i;
+	static char	  c[2];
+
+	if (sz > 3)
+		return(NULL);
+	i = atoi(p);
+	if (i < 0 || i > 255)
+		return(NULL);
+	c[0] = (char)i;
+	c[1] = '\0';
+	return(c);
+}
+
+
 /* 
  * Special character to string array.
  */