1 files changed, 54 insertions, 0 deletions
diff --git a/src/user/lib/libc/std/string.c b/src/user/lib/libc/std/string.c
index d8e4a48..619b8c6 100644
--- a/src/user/lib/libc/std/string.c
+++ b/src/user/lib/libc/std/string.c
@@ -119,3 +119,57 @@ char* format_hex(char *buf, unsigned v) {
 	}
 	return buf;
 }
+
+int printf_str_len(const char *format, va_list ap) {
+	int l = 0;
+	while (*format) {
+		if (*format == '%') {
+			format++;
+			if (*format == 'd' || *format == 'i') {
+				l += 15;
+				va_arg(ap, int);
+			} else if (*format == 'p') {
+				l += 11;
+				va_arg(ap, void*);
+			} else if (*format == 's') {
+				l += strlen(va_arg(ap, const char*));
+			}
+		} else {
+			l++;
+		}
+		format++;
+	}
+	return l;
+}
+
+int sprintf(char *buf, const char *fmt, ...) {
+	va_list ap;
+	va_start(ap, fmt);
+	int ret = vsprintf(buf, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+
+int vsprintf(char *buf, const char *format, va_list ap) {
+	char *end = buf;
+
+	while (*format) {
+		if (*format == '%') {
+			format++;
+			if (*format == 'd' || *format == 'i') {
+				end = format_int(end, va_arg(ap, int));
+			} else if (*format == 'p') {
+				end = format_hex(end, va_arg(ap, uint32_t));
+			} else if (*format == 's') {
+				const char *s = va_arg(ap, const char*);
+				strcpy(end, s);
+				end += strlen(s);
+			}
+			format++;
+		} else {
+			*(end++) = *(format++);
+		}
+	}
+	*end = 0;
+	return end - buf;
+}