libc/src/string/stpncpy.cpp

   1 //===-- Implementation of stpncpy -----------------------------------------===//
   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/stpncpy.h"
  10 #include "src/string/memory_utils/inline_bzero.h"
  11
  12 #include "src/__support/common.h"
  13
  14 namespace LIBC_NAMESPACE {
  15
  16 LLVM_LIBC_FUNCTION(char *, stpncpy,
  17                    (char *__restrict dest, const char *__restrict src,
  18                     size_t n)) {
  19   size_t i;
  20   // Copy up until \0 is found.
  21   for (i = 0; i < n && src[i] != '\0'; ++i)
  22     dest[i] = src[i];
  23   // When n>strlen(src), n-strlen(src) \0 are appended.
  24   if (n > i)
  25     inline_bzero(dest + i, n - i);
  26   return dest + i;
  27 }
  28
  29 } // namespace LIBC_NAMESPACE