strlen - calculate the length of a string
Standard C library (
libc,
-lc)
#include <string.h>
size_t strlen(const char *s);
The
strlen() function calculates the length of the string pointed to by
s, excluding the terminating null byte ('\0').
The
strlen() function returns the number of bytes in the string pointed
to by
s.
For an explanation of the terms used in this section, see
attributes(7).
Interface |
Attribute |
Value |
strlen () |
Thread safety |
MT-Safe |
POSIX.1-2001, POSIX.1-2008, C99, C11, SVr4, 4.3BSD.
In cases where the input buffer may not contain a terminating null byte,
strnlen(3) should be used instead.
string(3),
strnlen(3),
wcslen(3),
wcsnlen(3)