How to output single character in C with write?

Question

Could someone instruct me on how to print a single letter, for example "b" in C while using only the write function (not printf).

I'm pretty sure it uses

#include <unistd.h>

Could you also tell me how the write properties work? I don't really understand

int  write(  int  handle,  void  *buffer,  int  nbyte  );

Could some of you guys toss in a few C beginner tips as well?

I am using UNIX.

Answer 1

You have found your function, all you need now is to pass it proper parameters:

int handle = open("myfile.bin", O_WRONLY);
//... You need to check the result here
int count = write(handle, "b", 1); // Pass a single character
if (count == 1) {
    printf("Success!");
}

I did indeed want to use stdout. How do I write a version to display the whole alphabet?

You could use a pre-defined constant for stdout. It is called STDOUT_FILENO.

If you would like to write out the whole alphabet, you could do it like this:

for (char c = 'A' ; c <= 'Z' ; c++) {
    write(STDOUT_FILENO, &c, 1);
}

Demo.