strnlen (3)

Leading comments

Copyright (c) Bruno Haible <haible@clisp.cons.org>

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References consulted:
  GNU glibc-2 source code and manual

(The comments found at the beginning of the groff file "man3/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:

_XOPEN_SOURCE >= 700 || _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 (aq\0aq), but at most maxlen. In doing this, strnlen() looks only at the first maxlen bytes at 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 byte (aq\0aq) among the first maxlen bytes 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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