strbuf.c: add `strbuf_insertf()` and `strbuf_vinsertf()`

diff --git a/strbuf.h b/strbuf.h
index be02150df393a7741096babb53fd390e1d3cc1fe..8f8fe01e68dc868f4154c8b733f6a86b2df9c4bd 100644 (file)
--- a/strbuf.h
+++ b/strbuf.h
@@ -244,6 +244,15 @@ void strbuf_addchars(struct strbuf *sb, int c, size_t n);
  */
 void strbuf_insert(struct strbuf *sb, size_t pos, const void *, size_t);
 
+/**
+ * Insert data to the given position of the buffer giving a printf format
+ * string. The contents will be shifted, not overwritten.
+ */
+void strbuf_vinsertf(struct strbuf *sb, size_t pos, const char *fmt,
+                    va_list ap);
+
+void strbuf_insertf(struct strbuf *sb, size_t pos, const char *fmt, ...);
+
 /**
  * Remove given amount of data from a given position of the buffer.
  */