i am just starting with programming in linux.i am trying to fork a child process and replace it with the "sort" program. below is the code iam using for this.

i expeceted that when i invoked sort programm it would wait for me to give it input but instead the program just terminates.

how can i make the child process take input interactively?

#include <stdio.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
int main ()
{
pid_t pid;
pid = fork ();
if (pid == (pid_t) 0) {
execlp ("sort","sort",0);
}
else {
waitpid (pid, NULL, 0);
}
return 0;
}

I don't see any code in your post. Why isn't this in the programming forum?

That won't wait because the input file should be there already.
That should take standard input.

@linosaurusroot
i missed to paste the code first time i submitted the code but then immediately i did edit and pasted it. however below is the code. i tried execl("/bin/sort", "sort" , "-", (char *)0 ) but it didnt work, the program just terminates.

#include <stdio.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
int main ()
{
pid_t pid;
pid = fork ();
if (pid == (pid_t) 0) {
execlp ("sort","sort",0);
}
else {
waitpid (pid, NULL, 0);
}
return 0;
}

sorry about the confusion, my code has a line which was duplicating the standard input of child process to a stream created in the parent process.