Header File 

string.h, mbstring.h 

Category 

Memory and String Manipulation Routines, Inline Routines 

Prototype 

char *strncpy(char *dest, const char *src, size_t maxlen); 

wchar_t *wcsncpy(wchar_t *dest, const wchar_t *src, size_t maxlen); 

unsigned char *_mbsncpy(unsigned char *dest, const unsigned char *src, size_t maxlen); 

Description 

Copies a given number of bytes from one string into another, truncating or padding as necessary. 

strncpy copies up to maxlen characters from src into dest, truncating or null-padding dest. The target string, dest, might not be null-terminated if the length of src is maxlen or more. 

Return Value 

strncpy returns dest. 

Example  

#include <stdio.h>
#include <string.h>
int main(void)
{
   char string[10];
   char *str1 = "abcdefghi";
   strncpy(string, str1, 3);
   string[3] = '\0';
   printf("%s\n", string);
   return 0;
}

Portability