| STRLEN(3) | Library Functions Manual | STRLEN(3) | 
strlen, strnlen —
    find length of string
Standard C Library (libc, -lc)
#include
    <string.h>
size_t
  
  strlen(const
    char *s);
size_t
  
  strnlen(const
    char *s, size_t
    maxlen);
The
    strlen()
    function computes the length of the string s. The
    strnlen()
    function attempts to compute the length of s, but
    never scans beyond the first maxlen bytes of
    s.
The strlen() function returns the number
    of characters that precede the terminating NUL
    character. The strnlen() function returns either the
    same result as strlen() or
    maxlen, whichever is smaller.
The strlen() function conforms to
    ISO/IEC 9899:1990 (“ISO C90”).
    The strnlen() function conforms to
    IEEE Std 1003.1-2008 (“POSIX.1”).
| February 28, 2009 | macOS 15.6 |