Reading binary file in C (in chunks) - c

Question

I'm not good at C and I'm trying to do something simple. I want to open a binary file, read blocks of 1024 bytes of data and dump into a buffer, process the buffer, read another 1024 byes of data and keep doing this until EOF. I know how / what I want to do with the buffer, but it's the loop part and file I/O I keep getting stuck on.
PSEUDO code:
FILE *file;
unsigned char * buffer[1024];
fopen(myfile, "rb");
while (!EOF)
{
fread(buffer, 1024);
//do my processing with buffer;
//read next 1024 bytes in file, etc.... until end
}

Answer 1

fread() returns the number of bytes read. You can loop until that's 0.
FILE *file = NULL;
unsigned char buffer[1024]; // array of bytes, not pointers-to-bytes
size_t bytesRead = 0;
file = fopen(myfile, "rb");
if (file != NULL)
{
// read up to sizeof(buffer) bytes
while ((bytesRead = fread(buffer, 1, sizeof(buffer), file)) > 0)
{
// process bytesRead worth of data in buffer
}
}

Answer 2

#include <stdio.h>
#include <unistd.h> // For system calls write, read e close
#include <fcntl.h>
#define BUFFER_SIZE 1024
int main(int argc, char* argv[]) {
unsigned char buffer[BUFFER_SIZE] = {0};
ssize_t byte = 0;
int fd = open("example.txt", O_RDONLY);
while ((byte = read(fd, buffer, sizeof(buffer))) != 0) {
printf("%s", buffer);
memset(buffer, 0, BUFFER_SIZE);
}
close(fd);
return 0;
}
Edited code added
#include <stdio.h>
#include <unistd.h> // For system calls write, read e close
#include <fcntl.h>
#define BUFFER_SIZE 1024
int main(int argc, char* argv[]) {
unsigned char buffer[BUFFER_SIZE] = {0};
ssize_t byte = 0;
// open file in read mode
int fd = open("example.txt", O_RDONLY);
// file opening failure
if (fd == -1) {
printf("Failed to open file\n");
return -1;
}
// loop
while (1) {
// read buffer
byte = read(fd, buffer, sizeof(buffer));
// error
if (byte == -1) {
printf("Encountered an error\n");
break;
} else if (byte == 0) {
// file end exit loop
printf("File reading end\n");
break;
}
// printf file data
printf("%s", buffer);
memset(buffer, 0, BUFFER_SIZE);
}
// Close file
close(fd);
return 0;
}