1 files changed, 61 insertions, 0 deletions
diff --git a/include/c/str/cpy/stp/stpe/stpeprintf.h b/include/c/str/cpy/stp/stpe/stpeprintf.h
new file mode 100644
index 0000000..1a74dd8
--- /dev/null
+++ b/include/c/str/cpy/stp/stpe/stpeprintf.h
@@ -0,0 +1,61 @@
+// Copyright 2022 Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier:  LGPL-3.0-or-later WITH LGPL-3.0-linking-exception
+
+
+#ifndef INCLUDE_C_STR_CPY_STP_STPE_STPEPRINTF_H_
+#define INCLUDE_C_STR_CPY_STP_STPE_STPEPRINTF_H_
+
+
+#include <stdarg.h>
+#include <stdio.h>
+
+#include <c/str/cpy/stp/_compiler.h>
+
+
+#pragma clang assume_nonnull begin
+inline char *c_nullable c_stpeprintf(char *c_nullable dst, char *end,
+    const char *restrict fmt, ...);
+inline char *c_nullable c_vstpeprintf(char *c_nullable dst, char *end,
+    const char *restrict fmt, va_list ap);
+
+
+inline char *c_nullable
+c_stpeprintf(char *c_nullable dst, char *end, const char *restrict fmt, ...)
+{
+	char     *c_nullable p;
+	va_list  ap;
+
+	va_start(ap, fmt);
+	p = c_vstpeprintf(dst, end, fmt, ap);
+	va_end(ap);
+
+	return p;
+}
+
+
+inline char *c_nullable
+c_vstpeprintf(char *c_nullable dst, char *end, const char *restrict fmt,
+    va_list ap)
+{
+	int  len;
+
+	if (dst == end)
+		return end;
+	if (c_unlikely(dst == NULL))
+		return NULL;
+	c_impossible(dst > end);
+
+	len = vsnprintf(dst, end - dst, fmt, ap);
+
+	c_impossible(len < -1);
+	if (c_unlikely(len == -1))
+		return NULL;
+	if (len >= end - dst)
+		return end;
+
+	return dst + len;
+}
+#pragma clang assume_nonnull end
+
+
+#endif  // Header guard