[27/32] tools/nolibc: add snprintf() and friends

Commit Message

Thomas Weißschuh March 4, 2025, 7:10 a.m. UTC

Add more of the printf() functions.

Signed-off-by: Thomas Weißschuh <[e-mail]>
---
 tools/include/nolibc/stdio.h | 55 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

Comments

Willy Tarreau March 4, 2025, 8:01 a.m. UTC | #1

On Tue, Mar 04, 2025 at 08:10:57AM +0100, Thomas Weißschuh wrote:
> +static int _sprintf_cb(intptr_t _state, const char *buf, size_t size)

So logically we should have "nolibc" in that name as well.

Willy

Patch

diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index b484a19466394d55d7d21248031837238b58f3ff..e9f9cb2e8d9877221b442f9f3757d7ace1a5538c 100644
--- a/tools/include/nolibc/stdio.h
+++ b/tools/include/nolibc/stdio.h
@@ -389,6 +389,61 @@  int dprintf(int fd, const char *fmt, ...)
 	va_start(args, fmt);
 	ret = vdprintf(fd, fmt, args);
 	va_end(args);
+
+	return ret;
+}
+
+static int _sprintf_cb(intptr_t _state, const char *buf, size_t size)
+{
+	char **state = (char **)_state;
+
+	memcpy(*state, buf, size);
+	*state += size;
+	return 0;
+}
+
+static __attribute__((unused, format(printf, 3, 0)))
+int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
+{
+	char *state = buf;
+	int ret;
+
+	ret = _printf(_sprintf_cb, (intptr_t)&state, size, fmt, args);
+	if (ret < 0)
+		return ret;
+	buf[(size_t)ret < size ? (size_t)ret : size - 1] = '\0';
+	return ret;
+}
+
+static __attribute__((unused, format(printf, 3, 4)))
+int snprintf(char *buf, size_t size, const char *fmt, ...)
+{
+	va_list args;
+	int ret;
+
+	va_start(args, fmt);
+	ret = vsnprintf(buf, size, fmt, args);
+	va_end(args);
+
+	return ret;
+}
+
+static __attribute__((unused, format(printf, 2, 0)))
+int vsprintf(char *buf, const char *fmt, va_list args)
+{
+	return vsnprintf(buf, SIZE_MAX, fmt, args);
+}
+
+static __attribute__((unused, format(printf, 2, 3)))
+int sprintf(char *buf, const char *fmt, ...)
+{
+	va_list args;
+	int ret;
+
+	va_start(args, fmt);
+	ret = vsprintf(buf, fmt, args);
+	va_end(args);
+
 	return ret;
 }