NAME

strlen - calculate the length of a string

LIBRARY

Standard C library (libc, -lc)

SYNOPSIS

strlen - calculate the length of a string

Header Files

#include <cs50.h>
#include <string.h>

Prototype

int strlen(string s);

#include <string.h>
size_t strlen(const char *s);

DESCRIPTION

This function calculates the length of s.

The strlen() function calculates the length of the string pointed to by s, excluding the terminating null byte ('\0').

RETURN VALUE

This function returns the number of characters in s, excluding the terminating NUL byte (i.e., '\0').

The strlen() function returns the number of bytes in the string pointed to by s.

EXAMPLE

#include <cs50.h>
#include <stdio.h>
#include <string.h>

int main(void)
{
    string s = get_string("Input:  ");
    printf("Output: ");
    for (int i = 0, n = strlen(s); i < n; i++)
    {
        printf("%c", s[i]);
    }
    printf("\n");
}

ATTRIBUTES

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

Interface	Attribute	Value
strlen()	Thread safety	MT-Safe

STANDARDS

C11, POSIX.1-2008.

HISTORY

POSIX.1-2001, C89, SVr4, 4.3BSD.

NOTES

In cases where the input buffer may not contain a terminating null byte, strnlen(3) should be used instead.