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 ('\0'), 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
       ('\0') 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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GNU                                                2015-03-02                                         STRNLEN(3)