Add utf8_fprintf helper that returns correct number of columns

[git.git] / utf8.c

diff --git a/utf8.c b/utf8.c
index 5c61bbe1131e7bbdd939c8b815bd5222b872e3fb..c7bda66e3800abfd49eea2d6fafd95a2403a6b90 100644 (file)
--- a/utf8.c
+++ b/utf8.c
@@ -430,6 +430,27 @@ int same_encoding(const char *src, const char *dst)
        return !strcasecmp(src, dst);
 }
 
+/*
+ * Wrapper for fprintf and returns the total number of columns required
+ * for the printed string, assuming that the string is utf8.
+ */
+int utf8_fprintf(FILE *stream, const char *format, ...)
+{
+       struct strbuf buf = STRBUF_INIT;
+       va_list arg;
+       int columns;
+
+       va_start(arg, format);
+       strbuf_vaddf(&buf, format, arg);
+       va_end(arg);
+
+       columns = fputs(buf.buf, stream);
+       if (0 <= columns) /* keep the error from the I/O */
+               columns = utf8_strwidth(buf.buf);
+       strbuf_release(&buf);
+       return columns;
+}
+
 /*
  * Given a buffer and its encoding, return it re-encoded
  * with iconv.  If the conversion fails, returns NULL.