Header File 

string.h  

Category 

Memory and String Manipulation Routines, Inline Routines 

Prototype 

char *strnset(char *s, int ch, size_t n); 

wchar_t *_wcsnset(wchar_t *s, wchar_t ch, size_t n); 

unsigned char *_mbsnset(unsigned char *s, unsigned int ch, size_t n); 

Description 

Sets a specified number of characters in a string to a given character. 

strnset copies the character ch into the first n bytes of the string s. If n > strlen(s), then strlen(s) replaces n. It stops when n characters have been set, or when a null character is found. 

Return Value 

Each of these functions return s. 

Example  

#include <stdio.h>
#include <string.h>
int main(void)
{
   char *string = "abcdefghijklmnopqrstuvwxyz";
   char letter = 'x';
   printf("string before strnset: %s\n", string);
   strnset(string, letter, 13);
   printf("string after  strnset: %s\n", string);
   return 0;
}

Portability