From 40b0fa608877472b864bbc720dbd25ca4457509e Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Tue, 19 Aug 2008 17:49:24 +1000
Subject: [PATCH 1/1] Extraction of parts of documentation.

---
 tools/doc_extract.c | 170 ++++++++++++++++++++++++++++++++++++--------
 1 file changed, 141 insertions(+), 29 deletions(-)

diff --git a/tools/doc_extract.c b/tools/doc_extract.c
index b70325ea..a40e3b1a 100644
--- a/tools/doc_extract.c
+++ b/tools/doc_extract.c
@@ -11,39 +11,151 @@
 #include "talloc/talloc.h"
 #include "string/string.h"
 
+static char **grab_doc(const char *fname)
+{
+	char *file;
+	char **lines, **ret;
+	unsigned int i, num;
+	bool printing = false, printed = false;
+
+	file = grab_file(NULL, fname, NULL);
+	if (!file)
+		err(1, "Reading file %s", fname);
+	lines = strsplit(file, file, "\n", &num);
+	ret = talloc_array(NULL, char *, num+1);
+
+	num = 0;
+	for (i = 0; lines[i]; i++) {
+		if (streq(lines[i], "/**")) {
+			printing = true;
+			if (printed++)
+				talloc_append_string(ret[num], "\n");
+		} else if (streq(lines[i], " */")) 
+			printing = false;
+		else if (printing) {
+			if (strstarts(lines[i], " * "))
+				ret[num++] = talloc_strdup(ret, lines[i]+3);
+			else if (strstarts(lines[i], " *"))
+				ret[num++] = talloc_strdup(ret, lines[i]+2);
+			else
+				errx(1, "Malformed line %s:%u", fname, i);
+		}
+	}
+	ret[num] = NULL;
+	talloc_free(file);
+	return ret;
+}
+
+static bool is_blank(const char *line)
+{
+	return line && line[strspn(line, " \t\n")] == '\0';
+}
+
+static bool is_section(const char *line)
+{
+	unsigned int len;
+
+	len = strcspn(line, " \t\n:");
+	if (len == 0)
+		return false;
+
+	return line[len] == ':' && is_blank(line+len+1);
+}
+
+
+static bool end_section(const char *line)
+{
+	return !line || is_section(line);
+}
+
+static unsigned int find_section(char **lines, const char *name)
+{
+	unsigned int i;
+
+	for (i = 0; lines[i]; i++) {
+		if (!is_section(lines[i]))
+			continue;
+		if (strncasecmp(lines[i], name, strlen(name)) != 0)
+			continue;
+		if (lines[i][strlen(name)] == ':')
+			break;
+	}
+	return i;
+}
 
 int main(int argc, char *argv[])
 {
-	unsigned int i, j;
-
-	for (i = 1; i < argc; i++) {
-		char *file;
-		char **lines;
-		bool printing = false, printed = false;
-
-		file = grab_file(NULL, argv[i]);
-		if (!file)
-			err(1, "Reading file %s", argv[i]);
-		lines = strsplit(file, file, "\n", NULL);
-
-		for (j = 0; lines[j]; j++) {
-			if (streq(lines[j], "/**")) {
-				printing = true;
-				if (printed++)
-					puts("\n");
-			} else if (streq(lines[j], " */"))
-				printing = false;
-			else if (printing) {
-				if (strstarts(lines[j], " * "))
-					puts(lines[j] + 3);
-				else if (strstarts(lines[j], " *"))
-					puts(lines[j] + 2);
-				else
-					errx(1, "Malformed line %s:%u",
-					     argv[i], j);
+	unsigned int i;
+	const char *type;
+
+	if (argc < 3)
+		errx(1, "Usage: doc_extract TYPE <file>...\n"
+		     "Where TYPE is author|licence|maintainer|summary|description|example|all");
+
+	type = argv[1];
+	for (i = 2; i < argc; i++) {
+		unsigned int line;
+		char **lines = grab_doc(argv[i]);
+
+		if (!lines[0])
+			errx(1, "No documentation in file");
+
+		/* Simple one-line fields. */
+		if (streq(type, "author")
+		    || streq(type, "maintainer")
+		    || streq(type, "licence")) {
+			line = find_section(lines, type);
+			if (lines[line]) {
+				if (!lines[line+1])
+					errx(1, "Malformed %s, end of file",
+					     type);
+				puts(lines[line+1]);
 			}
-		}
-		talloc_free(file);
+		} else if (streq(type, "summary")) {
+			/* Summary comes after - on first line. */
+			char *dash;
+
+			dash = strchr(lines[0], '-');
+			if (!dash)
+				errx(1, "Malformed first line: no -");
+			dash += strspn(dash, "- ");
+			puts(dash);
+		} else if (streq(type, "description")) {
+			line = 1;
+			while (is_blank(lines[line]))
+				line++;
+
+			while (!end_section(lines[line]))
+				puts(lines[line++]);
+		} else if (streq(type, "example")) {
+			line = find_section(lines, type);
+			if (lines[line]) {
+				unsigned int strip;
+				line++;
+
+				while (is_blank(lines[line]))
+					line++;
+
+				/* Examples can be indented.  Take cue
+				 * from first non-blank line. */
+				if (lines[line])
+					strip = strspn(lines[line], " \t");
+
+				while (!end_section(lines[line])) {
+					if (strspn(lines[line], " \t") >= strip)
+						puts(lines[line] + strip);
+					else
+						puts(lines[line]);
+					line++;
+				}
+			}
+		} else if (streq(type, "all")) {
+			for (line = 0; lines[line]; line++)
+				puts(lines[line]);
+		} else
+			errx(1, "Unknown type '%s'", type);
+			
+		talloc_free(lines);
 	}
 	return 0;
 }
-- 
2.39.2