Can't open() second file C - c

Question

For some reason if I do a second open, it compiles but when I try to run it, it does nothing like it's locked. It's missing a lot of other functions, because it's a work in progress for a school project. If I remove one of the open(), the program runs just fine.
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define BUFFER_SIZE 100
#define INPUT "/tmp/father"
int main(int argc, char **argv)
{
int fds;
int fd;
char mode[BUFFER_SIZE];
char buffer[BUFFER_SIZE];
unlink(INPUT);
mkfifo(INPUT, S_IRUSR | S_IWUSR);
if(argc != 2)
{
fputs("Argumentos invalidos\n", stderr);
exit(EXIT_FAILURE);
}
fd = open(argv[1], O_WRONLY);
if(fd == -1)
{
fprintf(stderr, "\nCan't open pipe\n");
exit(EXIT_FAILURE);
}
fds = open(INPUT, O_RDONLY);
if(fds == -1)
{
fprintf(stderr, "\nCan't open pipe\n");
exit(EXIT_FAILURE);
}
while(1)
{
fgets(buffer,BUFFER_SIZE,stdin);
sscanf(buffer,"%s", mode);
write(fd,buffer,strlen(buffer));
}
}

Answer 1

Are you sure there's a problem? You are reading from stdin (the fgets at the bottom), and writing to the pipe. What you're missing is something reading from the pipe. So if in another terminal you type:
$ cat /tmp/father
then anything you type into your prog will appear there.
So, in one terminal I do:
$ ./test /tmp/father
line one
line two
And in the second terminal:
$ cat /tmp/father
and I see:
line one
line two
No?
P.S. You are doing sscanf to read from buffer and write to mode, then writing out the buffer string. Not that it matters, but you're not using mode.