strnlen(3)

NAME

strnlen - nonstring length

Standard C library (libc, -lc)

#include <string.h>  // see memory.h(3head)

size_t strnlen(const char strn[], size_t n);

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

This function determines the length of the character sequence contained in the array pointed to by strn.

If strn contains a string, the array can have less than n elements.

It is equivalent to

(memchr(strn, '\0', n) ?: strn + n) - strn

The strnlen() function returns the number of nonnull characters in strn.

For an explanation of the terms used in this section, see attributes(7).

Interface	Attribute	Value
strnlen()	Thread safety	MT-Safe

POSIX.1-2008.

POSIX.1-2008.