C programming print a certain amount of bytes to screen

Question

How can I make the program read \"partSize\" amount of bytes and print it to the screen? Let\'s say that I am opening a text file that contains 100 characters in total. If p

Answer 1

You need to check the return value, and update the length in each iteration:

ssize_t count, total;
total = 0;
char *buf = BUFFER;
while (partSize) {
    count = read(openDescriptorOriginal, buf, partSize);
    if (count < 0) {
        /* handle error */
        break;
    }
    if (count == 0)
        break;
    buf += count;
    total += count;
    partSize -= count;
}
write (1, BUFFER, total);

total will contain the number of bytes read.