Executing wc command on child process using pipeline - c

Question

I'm writing a program that executes the word count command on the child process. The father process should send a sequence of lines entered by the user trough a pipeline to the child process.
I tried to do this but I ended up with an error.
This is my code:
int main ()
{
int fd[2];
char buff;
int pid;
int pip;
pid = fork();
pip = pipe(fd);
if (pid != 0)
{
pip = pipe(fd);
if (pipe == 0)
{
while (read(fd[0], &buff,1) > 0 )
{
write (fd[1],&buff,1);
}
close(fd[0]);
_exit(0);
}
}
else
{
dup2(fd[1],1);
close(fd[1]);
execlp ("wc","wc",NULL);
_exit(-1);
}
return 0;
}
I've also tried to use dup2 to associate the standard input from the child to the read descriptor of the pipe created by the father process.
But I get this error : wc: standard input: Input/output error.
How can I solve this?
UPDATED (the error is solved but I get an infinite loop)
int main ()
{
int fd[2];
char buff;
int pid;
int pip;
pip = pipe(fd);
if (pip == 0)
{
pid = fork();
if (pid != 0)
{
while (read(fd[0], &buff,1) > 0 )
{
write (fd[1],&buff,1);
}
close(fd[0]);
}
else {
dup2(fd[1],1);
close(fd[1]);
execlp ("wc","wc",NULL);
_exit(-1);
}
}
return 0;
}

Answer 1

#include <unistd.h>
int main ()
{
int fd[2];
char buff;
int pid;
int pip;
int status;
pip = pipe(fd);
if (pip == 0)
{
pid = fork();
if (pid != 0)
{
close(fd[0]);
while (read(0, &buff,1) > 0 )
{
write (fd[1],&buff,1); /* your old loop forwarded internally in the pipe only*/
}
close(fd[1]);
} else {
dup2(fd[0],0); /* you had dup2(fd[1], 1), replacing stdout of wc with the write end from wc */
close(fd[0]);
close(fd[1]);
execlp ("wc","wc",NULL);
_exit(-1);
}
}
wait(&status); /* reap the child process */
return 0;
}