The fread() function is defined in the stdio.h header file. It helps to read the data from the given specified stream into the array. The starting address of the memory location where data need to be stored after file reading is specified by the pointer.
size_t fread(void *ptr, size_t size, size_t nmemb, FILE *stream); #where stream should be a file pointer
The fread() function takes four parameters. This function is mainly used for reading binary data, it is a complementary function of fwrite().
| Parameter | Description | Required / Optional |
|---|---|---|
| ptr | the pointer to a block of memory with a minimum size of size*nmemb bytes | Required |
| size | size in bytes of each element to be read | 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 input stream | Required |
The return value of fread() function is the total number of elements successfully read. 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 chr[] = "C Programming";
char buf[100];
/* Open file */
pnt = fopen("myfile.txt", "w+");
/* Write data*/
fwrite(chr, strlen(chr) + 1, 1, pnt);
fseek(pnt, 0, SEEK_SET);
/* Read and display data */
fread(buf, strlen(chr)+1, 1, pnt);
printf("%s\n", buf);
fclose(pnt);
return(0);
}
Output:
C Programming
#include <stdio.h>
int main (){
int buf;
int val = 2431;
// Creating file and storing value
FILE * stream;
stream = fopen("myfile.txt", "w");
fwrite(&val;, sizeof(int), 1, stream);
fclose(stream);
// Reading value from file
stream = fopen("myfile.txt", "r");
fread(&buf;, sizeof(int), 1, stream);
printf("High score readed is: %d\n",buf);
fclose(stream);
return(0);
}
Output:
High score readed is:2431
