The fwrite() function is defined in the stdio.h header file. It helps to write the data into the given specified stream from the array pointed to, by ptr.
size_t fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream); #where stream should be a file pointer
The fwrite() function takes four parameters. This function is mainly used for writing binary data, it is a complementary function of fread().
Parameter | Description | Required / Optional |
---|---|---|
ptr | the pointer to the array of elements to be written | Required |
size | the size in bytes of each element to be written | Required |
nmemb | the number of elements, each one with a size of size bytes | Required |
stream | the pointer to a FILE object that specifies an output stream | Required |
The return value of fwrite() function is the total number of elements successfully write. It is returned as a size_t object, which is an integral data type.
Input | Return Value |
---|---|
successful | integer value equivalent to nmemb |
error or EOF | a value less than nmemb |
#include <stdio.h>
#include <string.h>
int main()
{
FILE *pnt;
char st[] = "Welcome to C Programming";
pnt = fopen( "myfile.txt" , "w" );
fwrite(st , 1 , sizeof(st) , pnt );
fclose(pnt);
return(0);
}
Output:
Welcome to C Programming
#include <stdio.h>
int main (){
FILE *pnt;
int cnt;
char ar[6] = "hello";
pnt = fopen("mysample.txt", "wb");
cnt = fwrite(ar, 1, 5, pnt);
fclose(pnt);
return 0;
}
Output:
/*opens a file named sample.txt, writes an array of characters(below text) to the file, and closes it. */ hello