Bad file descriptor

Question

I'm learning about file descriptors and I wrote this code:

#include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <fcntl.h>  int fdrd, fdwr, fdwt; char c;  main (int argc, char *argv[]) {      if((fdwt = open("output", O_CREAT, 0777)) == -1) {         perror("Error opening the file:");         exit(1);     }      char c = 'x';      if(write(fdwt, &c, 1) == -1) {         perror("Error writing the file:");     }      close(fdwt);     exit(0);  } 

, but I'm getting: Error writing the file:: Bad file descriptor

I don't know what could be wrong, since this is a very simple example.

Answer 1

Try this:

open("output", O_CREAT|O_WRONLY, 0777) 

Answer 2

I think O_CREAT alone is not enough. Try adding O_WRONLY as flag to the open command.