xref: /aosp_15_r20/external/llvm-libc/src/string/strncpy.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===-- Implementation of strncpy -----------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "src/string/strncpy.h"
10 
11 #include "src/__support/common.h"
12 #include "src/__support/macros/config.h"
13 #include <stddef.h> // For size_t.
14 
15 namespace LIBC_NAMESPACE_DECL {
16 
17 LLVM_LIBC_FUNCTION(char *, strncpy,
18                    (char *__restrict dest, const char *__restrict src,
19                     size_t n)) {
20   size_t i = 0;
21   // Copy up until \0 is found.
22   for (; i < n && src[i] != '\0'; ++i)
23     dest[i] = src[i];
24   // When n>strlen(src), n-strlen(src) \0 are appended.
25   for (; i < n; ++i)
26     dest[i] = '\0';
27   return dest;
28 }
29 
30 } // namespace LIBC_NAMESPACE_DECL
31