NAME
strlen, strnlen
— find length of a
string
SYNOPSIS
#include
<string.h>
size_t
strlen(const
char *s);
size_t
strnlen(const
char *s, size_t
maxlen);
DESCRIPTION
The
strlen()
function computes the length of the string s.
The
strnlen()
function computes the length of the string s, up to
maxlen characters. The
strnlen() function will never attempt to address
more than maxlen characters, making it suitable for
use with character arrays that are not guaranteed to be NUL-terminated.
RETURN VALUES
The strlen() function returns the number
of characters that precede the terminating NUL character.
The strnlen() function returns the number
of characters that precede the terminating NUL or
maxlen, whichever is smaller.
SEE ALSO
STANDARDS
The strlen() function conforms to
ANSI X3.159-1989
(“ANSI C89”).
The strlen() and
strnlen() functions conform to IEEE
Std 1003.1-2008 (“POSIX.1”).
HISTORY
The strlen() function first appeared in
Version 6 AT&T UNIX. The
strnlen() function appeared in glibc 2.0 and was
reimplemented for OpenBSD 4.8.