STRLEN(3) Library Functions Manual STRLEN(3)

strlen, strnlenfind 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 () function computes the length of the string s. The () 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.

string(3), wcslen(3), wcswidth(3)

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 15.2