misc: Add `vformat_len()`

This works exactly like `format_len()`, except that it uses `va_list`
rather than variadic arguments.

2 files changed, 7 insertions, 0 deletions

diff --git a/misc.c b/misc.c
index 4c0cab0..6e10a57 100644
--- a/misc.c
+++ b/misc.c
@@ -201,6 +201,10 @@ char *skip_whitespace(const char *str) {
 	}
 }
 
+int vformat_len(const char *fmt, va_list args) {
+	return vsnprintf(NULL, 0, fmt, args);
+}
+
 int format_len(const char *fmt, ...) {
 	int len = 0;
 	va_list args;
diff --git a/misc.h b/misc.h
index 3a653e2..9110197 100644
--- a/misc.h
+++ b/misc.h
@@ -1,6 +1,8 @@
 #ifndef MISC_H
 #define MISC_H
 
+#include <stdarg.h>
+
 extern char *read_file(const char *filename, long *size);
 extern char *find_delm(char *str, const char *delm, int skip_delm);
 extern char *get_str_delm_range(char *str, const char *start_delm, const char *end_delm, char **rhs);
@@ -16,6 +18,7 @@ extern char *find_alpha(const char *str);
 extern char *create_num_str(const char *str, int num);
 extern int is_empty(const char *str);
 extern char *skip_whitespace(const char *str);
+extern int vformat_len(const char *fmt, va_list args);
 extern int format_len(const char *fmt, ...);
 extern int is_dir(const char *path);
 extern void mkdirp(const char *path, int mode);