STRNLEN(3) Linux Programmer's Manual STRNLEN(3)
NAME
strnlen - determine the length of a fixed-size string
SYNOPSIS
#include <string.h>
size_t strnlen(const char *s, size_t maxlen);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
strnlen():
Since glibc 2.10:
_POSIX_C_SOURCE >= 200809L
Before glibc 2.10:
_GNU_SOURCE
DESCRIPTION
The strnlen() function returns the number of bytes in the string
pointed to by s, excluding the terminating null byte ('\0'), but at
most maxlen. In doing this, strnlen() looks only at the first maxlen
characters in the string pointed to by s and never beyond s+maxlen.
RETURN VALUE
The strnlen() function returns strlen(s), if that is less than maxlen,
or maxlen if there is no null terminating ('\0') among the first maxlen
characters pointed to by s.
ATTRIBUTES
For an explanation of the terms used in this section, see at-
tributes(7).
+----------+---------------+---------+
|Interface | Attribute | Value |
+----------+---------------+---------+
|strnlen() | Thread safety | MT-Safe |
+----------+---------------+---------+
CONFORMING TO
POSIX.1-2008.
SEE ALSO
strlen(3)
COLOPHON
This page is part of release 5.07 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
GNU 2019-03-06 STRNLEN(3)