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Diffstat (limited to 'string/strlcpy.c')
-rw-r--r-- | string/strlcpy.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/string/strlcpy.c b/string/strlcpy.c new file mode 100644 index 0000000..7a0df3e --- /dev/null +++ b/string/strlcpy.c @@ -0,0 +1,46 @@ +/* Copy a null-terminated string to a fixed-size buffer, with length checking. + Copyright (C) 2023 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <string.h> + +size_t +__strlcpy (char *__restrict dest, const char *__restrict src, size_t size) +{ + size_t src_length = strlen (src); + + if (__glibc_unlikely (src_length >= size)) + { + if (size > 0) + { + /* Copy the leading portion of the string. The last + character is subsequently overwritten with the NUL + terminator, but the destination size is usually a + multiple of a small power of two, so writing it twice + should be more efficient than copying an odd number of + bytes. */ + memcpy (dest, src, size); + dest[size - 1] = '\0'; + } + } + else + /* Copy the string and its terminating NUL character. */ + memcpy (dest, src, src_length + 1); + return src_length; +} +libc_hidden_def (__strlcpy) +weak_alias (__strlcpy, strlcpy) |