Syntax
#include <string.h> char *strncpy(char *string1, const char *string2, size_t count);Description
strncpy copies count bytes of string2 to string1. If count is less than or equal to the length of string2, a null byte (\0) is not appended to the copied string. If count is greater than the length of string2, the string1 result is padded with null bytes (\0) up to length count.
strncpy returns a pointer to string1.
This example demonstrates the difference between strcpy and strncpy.
#include <stdio.h>
#include <string.h>
#define SIZE 40
int main(void)
{
char source[SIZE] = "123456789";
char source1[SIZE] = "123456789";
char destination[SIZE] = "abcdefg";
char destination1[SIZE] = "abcdefg";
char *return_string;
int index = 5;
/* This is how strcpy works */
printf("destination is originally = '%s'\n", destination);
return_string = strcpy(destination, source);
printf("After strcpy, destination becomes '%s'\n\n", destination);
/* This is how strncpy works */
printf("destination1 is originally = '%s'\n", destination1);
return_string = strncpy(destination1, source1, index);
printf("After strncpy, destination1 becomes '%s'\n", destination1);
return 0;
/****************************************************************************
The output should be:
destination is originally = 'abcdefg'
After strcpy, destination becomes '123456789'
destination1 is originally = 'abcdefg'
After strncpy, destination1 becomes '12345fg'
****************************************************************************/
}
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