pipe in C stuck when calling `wc` or `grep` - c

Question

Problem - when calling ls -l | grep etc, stuck on grep (grep child process does not exit)
trying to run "ls | grep r" with "execvp()" suggests that
need to close file descriptors
wait outside of the forking loop
IMO I have performed both of above but the problem still exists.
Any opinion is welcome, thanks!
Note that below is a hard-coded version for 2 pipes only
#include <sys/wait.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
int main()
{
int i = 0;
int pfd[2];
if (pipe(pfd) != 0)
{
printf("Error creating pipe\n");
exit(errno);
}
char **ptr = get_pipes(); // pipes as array of strings
char *command = *ptr;
while (command != NULL)
{
if (i == 2)
break; // hard code to ignore all commands after 2nd pipe
char **args = parse_cmd(command); // this parses a space-separated command as arguments
pid_t pid = fork();
if (pid == 0 && i == 0) // 1st pipe, 1st child
{
close(pfd[0]); // close pipe read end
dup2(pfd[1], 1); // set pipe write end to stdout
if (execvp(args[0], args) == -1)
{
fprintf(stderr, "%s: %s\n", args[0], strerror(errno));
exit(EXIT_FAILURE);
}
}
else if (pid == 0 && i == 1) // 2nd pipe, 2nd child
{
close(pfd[1]); // close pipe write end
dup2(pfd[0], 0); // set pipe read end to stdin
if (execvp(args[0], args) == -1)
{
fprintf(stderr, "'%s': %s\n", args[0], strerror(errno));
exit(EXIT_FAILURE);
}
// exit(EXIT_SUCCESS);
}
else if (pid > 0) // parent
{
printf("Parent pid: %d and child's pid is %d\n", (int)getpid(), (int)pid);
}
command = *++ptr;
i++;
}
pid_t zombie_pid;
int status;
do
{
zombie_pid = waitpid(-1, &status, 0);
printf("Child PID %d died with status %d\n", (int)zombie_pid, WEXITSTATUS(status));
} while (zombie_pid > 0);
}