xref: /Universal-ctags/gnulib/strnlen.c (revision a939078a69878851c19820eb92e6cb95ba429546)
1*a939078aSHiroo HAYASHI /* Find the length of STRING, but scan at most MAXLEN characters.
2*a939078aSHiroo HAYASHI    Copyright (C) 2005-2007, 2009-2021 Free Software Foundation, Inc.
3*a939078aSHiroo HAYASHI    Written by Simon Josefsson.
4*a939078aSHiroo HAYASHI 
5*a939078aSHiroo HAYASHI    This file is free software: you can redistribute it and/or modify
6*a939078aSHiroo HAYASHI    it under the terms of the GNU Lesser General Public License as
7*a939078aSHiroo HAYASHI    published by the Free Software Foundation; either version 2.1 of the
8*a939078aSHiroo HAYASHI    License, or (at your option) any later version.
9*a939078aSHiroo HAYASHI 
10*a939078aSHiroo HAYASHI    This file is distributed in the hope that it will be useful,
11*a939078aSHiroo HAYASHI    but WITHOUT ANY WARRANTY; without even the implied warranty of
12*a939078aSHiroo HAYASHI    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13*a939078aSHiroo HAYASHI    GNU Lesser General Public License for more details.
14*a939078aSHiroo HAYASHI 
15*a939078aSHiroo HAYASHI    You should have received a copy of the GNU Lesser General Public License
16*a939078aSHiroo HAYASHI    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
17*a939078aSHiroo HAYASHI 
18*a939078aSHiroo HAYASHI #include <config.h>
19*a939078aSHiroo HAYASHI 
20*a939078aSHiroo HAYASHI #include <string.h>
21*a939078aSHiroo HAYASHI 
22*a939078aSHiroo HAYASHI /* Find the length of STRING, but scan at most MAXLEN characters.
23*a939078aSHiroo HAYASHI    If no '\0' terminator is found in that many characters, return MAXLEN.  */
24*a939078aSHiroo HAYASHI 
25*a939078aSHiroo HAYASHI size_t
strnlen(const char * string,size_t maxlen)26*a939078aSHiroo HAYASHI strnlen (const char *string, size_t maxlen)
27*a939078aSHiroo HAYASHI {
28*a939078aSHiroo HAYASHI   const char *end = memchr (string, '\0', maxlen);
29*a939078aSHiroo HAYASHI   return end ? (size_t) (end - string) : maxlen;
30*a939078aSHiroo HAYASHI }
31