1 files changed, 22 insertions, 3 deletions
diff --git a/pit/src/utils.c b/pit/src/utils.c
index 75d59a6..ac8087c 100644
--- a/pit/src/utils.c
+++ b/pit/src/utils.c
@@ -11,8 +11,10 @@ enum vsnprintf_mode {
 #define SCRATCH_LEN 256
 #define WRITE(c) { buf[idx++] = c; if (idx >= len - 1) goto done; }
 #define WRITE_SCRATCH(c) { scratch[sidx++] = c; if (sidx >= SCRATCH_LEN) goto error; }
-int pit_libc_string_vsnprintf(char *buf, size_t len, char *format, va_list ap) {
-    // vsnprintf
+int pit_vsnprintf_helper(
+    char *buf, size_t len, char *format, va_list ap,
+    pit_printf_handler *handlers, i64 handlers_len, void *data
+) {
     size_t idx = 0;
     size_t flen = pit_libc_string_strlen(format);
     size_t fidx = 0;
@@ -81,8 +83,21 @@ int pit_libc_string_vsnprintf(char *buf, size_t len, char *format, va_list ap) {
                 mode = VSNPRINTF_MODE_NORMAL;
                 break;
             }
-            default: goto error;
+            default:
+                if (handlers) {
+                    for (i64 i = 0; i < handlers_len; ++i) {
+                        if (c == handlers[i].specifier) {
+                            i64 res = handlers[i].callback(ap, buf + idx, len - idx, data);
+                            if (res < 0) goto error;
+                            idx += (size_t) res;
+                            mode = VSNPRINTF_MODE_NORMAL;
+                            goto handled;
+                        }
+                    }
+                }
+                goto error;
             }
+        handled:
             break;
         }
     }
@@ -92,6 +107,10 @@ done:
 error:
     return -1;
 }
+int pit_libc_string_vsnprintf(char *buf, size_t len, char *format, va_list ap) {
+    // vsnprintf
+    return pit_vsnprintf_helper(buf, len, format, ap, NULL, 0, NULL);
+}
 int pit_libc_string_snprintf(char *buf, size_t len, char *format, ...) {
     va_list ap;
     va_start(ap, format);