STRNLEN
Section: Linux Programmer's Manual (3)
Updated: 2020-12-21
Page Index
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-1].
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
attributes(7).
| Interface | Attribute | Value
|
|
strnlen()
| Thread safety | MT-Safe
|
CONFORMING TO
POSIX.1-2008.
SEE ALSO
strlen(3)
COLOPHON
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