[PATCH v7 05/11] trailer: parse trailers from stdin

[Christian Couder <chriscool@tuxfamily.org>]

Read trailers from stdin, parse them and put the result into a doubly linked
list.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
 trailer.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)

diff --git a/trailer.c b/trailer.c
index 43cbf10..910eddb 100644
--- a/trailer.c
+++ b/trailer.c
@@ -50,6 +50,14 @@ static size_t alnum_len(const char *buf, size_t len)
 	return len;
 }
 
+static inline int contains_only_spaces(const char *str)
+{
+	const char *s = str;
+	while (*s && isspace(*s))
+		s++;
+	return !*s;
+}
+
 static void free_trailer_item(struct trailer_item *item)
 {
 	free(item->conf.name);
@@ -476,3 +484,71 @@ static struct trailer_item *process_command_line_args(int argc, const char **arg
 
 	return arg_tok_first;
 }
+
+static struct strbuf **read_stdin(void)
+{
+	struct strbuf **lines;
+	struct strbuf sb = STRBUF_INIT;
+
+	if (strbuf_read(&sb, fileno(stdin), 0) < 0)
+		die_errno(_("could not read from stdin"));
+
+	lines = strbuf_split(&sb, '\n');
+
+	strbuf_release(&sb);
+
+	return lines;
+}
+
+/*
+ * Return the the (0 based) index of the first trailer line
+ * or the line count if there are no trailers.
+ */
+static int find_trailer_start(struct strbuf **lines)
+{
+	int start, empty = 1, count = 0;
+
+	/* Get the line count */
+	while (lines[count])
+		count++;
+
+	/*
+	 * Get the start of the trailers by looking starting from the end
+	 * for a line with only spaces before lines with one ':'.
+	 */
+	for (start = count - 1; start >= 0; start--) {
+		if (contains_only_spaces(lines[start]->buf)) {
+			if (empty)
+				continue;
+			return start + 1;
+		}
+		if (strchr(lines[start]->buf, ':')) {
+			if (empty)
+				empty = 0;
+			continue;
+		}
+		return count;
+	}
+
+	return empty ? count : start + 1;
+}
+
+static void process_stdin(struct trailer_item **in_tok_first,
+			  struct trailer_item **in_tok_last)
+{
+	struct strbuf **lines = read_stdin();
+	int start = find_trailer_start(lines);
+	int i;
+
+	/* Print non trailer lines as is */
+	for (i = 0; lines[i] && i < start; i++)
+		printf("%s", lines[i]->buf);
+
+	/* Parse trailer lines */
+	for (i = start; lines[i]; i++) {
+		struct trailer_item *new = create_trailer_item(lines[i]->buf);
+		add_trailer_item(in_tok_first, in_tok_last, new);
+	}
+
+	strbuf_list_free(lines);
+}
-- 
1.8.5.2.204.gcfe299d.dirty