===================================================================
RCS file: /cvs/pod2mdoc/pod2mdoc.c,v
retrieving revision 1.8
retrieving revision 1.9
diff -u -p -r1.8 -r1.9
--- pod2mdoc/pod2mdoc.c	2014/03/23 23:57:38	1.8
+++ pod2mdoc/pod2mdoc.c	2014/03/24 01:07:30	1.9
@@ -1,4 +1,4 @@
-/*	$Id: pod2mdoc.c,v 1.8 2014/03/23 23:57:38 kristaps Exp $ */
+/*	$Id: pod2mdoc.c,v 1.9 2014/03/24 01:07:30 kristaps Exp $ */
 /*
  * Copyright (c) 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  *
@@ -158,6 +158,77 @@ formatescape(const char *buf, size_t *start, size_t en
 }
 
 /*
+ * Run some heuristics to intuit a link format.
+ * I recognise L<foo::bar> as a Perl manpage, printing it in section 3p;
+ * or a general UNIX foo(5) manpage.
+ * If I recognise one, I set "start" to be the end of the sequence so
+ * that the caller can safely just continue processing.
+ * Otherwise, I don't touch "start".
+ */
+static int
+trylink(const char *buf, size_t *start, size_t end, size_t dsz)
+{
+	size_t		sv, nstart, nend, i, j;
+	int		hasdouble;
+
+	/* 
+	 * Scan to the start of the terminus. 
+	 * This function is more or less replicated in the formatcode()
+	 * for null or index formatting codes.
+	 */
+	hasdouble = 0;
+	for (sv = nstart = *start; nstart < end; nstart++) {
+		/* Do we have a double-colon? */
+		if (':' == buf[nstart] && 
+			nstart > sv &&
+			':' == buf[nstart - 1])
+			hasdouble = 1;
+		if ('>' != buf[nstart])
+			continue;
+		else if (dsz == 1)
+			break;
+		assert(nstart > 0);
+		if (' ' != buf[nstart - 1])
+			continue;
+		i = nstart;
+		for (j = 0; i < end && j < dsz; j++) 
+			if ('>' != buf[i++])
+				break;
+		if (dsz == j) 
+			break;
+	}
+	
+	/* We don't care about stubs. */
+	if (nstart == end || nstart == *start)
+		return(0);
+
+	/* Set nend to the end of content. */
+	nend = nstart;
+	if (dsz > 1)
+		nend--;
+
+	/*
+	 * Provide for some common invocations of the link primitive.
+	 * First, allow us to link to other Perl manuals.
+	 */
+	if (hasdouble)
+		printf("Xr %.*s 3p", 
+			(int)(nend - sv), &buf[sv]);
+	else if (nend - sv > 3 && isalnum(buf[sv]) && 
+			')' == buf[nend - 1] && 
+			isdigit((int)buf[nend - 2]) &&
+			'(' == buf[nend - 3]) 
+		printf("Xr %.*s %c", 
+			(int)(nend - 3 - sv),
+			&buf[sv], buf[nend - 2]);
+	else
+		return(0);
+
+	*start = nstart;
+	return(1);
+}
+
+/*
  * We're at the character in front of a format code, which is structured
  * like X<...> and can contain nested format codes.
  * This consumes the whole format code, and any nested format codes, til
@@ -284,13 +355,13 @@ formatcode(const char *buf, size_t *start, 
 			printf("Qo Li ");
 			break;
 		case (FMT_LINK):
-			printf("Lk ");
+			if ( ! trylink(buf, start, end, dsz))
+				printf("No ");
 			break;
 		case (FMT_FILE):
 			printf("Pa ");
 			break;
 		case (FMT_NBSP):
-			/* TODO. */
 			printf("No ");
 			break;
 		default: