The goal of this assignment is to familiarize with system calls such as `fork`, `exec`, `wait`, `exit` and so on,
to spawn and terminate other user programs.
The main method `mulproc.c`
The main method contains the following steps:
```c
int main(void) {
// Step 1: Fork the first child process to run `testalphabet` program.
// Step 2: Fork the second child process to run `testspecial` program.
// Step 3: Wait for the first child process to finish and print a message.
// Step 4: Wait for the second child process to finish and print a message.
// Step 5: End the program.
}
```
Step 1 & 2: Forking child processes
In both steps, first fork a child process. If in the child process,
print a message indicating that child is starting to run its show
- `testalphabet`
- `testspecial`
use `exec` to replace the current process with the new program
The parent process does nothing and continues to the next step
Step 3 & 4: Waiting for child processes
In these steps, we're playing the waiting game for each child process to wrap up their performance.
After each wait call, we announce to the world that the child process has finished their gig.
Step 5: End of the show
The grand finale happens after both child processes have exited stage left,
and we've announced their departure to the crowd.
.
the curtain falls,
.
.
the lights dim,
.
.
.
and the program ends.
Important Considerations
Order of the Show:
The order in which testalphabet and testspecial start might not be the same as the order
in mind when we forked the child processes.
That's because the show's schedule is managed by the OS,
it can switch things up based on a whole bunch of factors.
If the order of the performance really matters, we might need to consider "synchronizing" the processes.
Error Handling Mishaps:
The plan above assumes that all goes well with the system calls (fork, exec, and wait).
In reality, things can go sideways and when they do,
should be prepared to handle any problems and keep the show running.
Finding the Right Stage executable files:
The exec function needs the exact location of the testalphabet and testspecial programs.
Curtain Call, (Child Termination sounds aggressive):
The requirement to announce when a child process wraps up their program can be a bit tricky.
Technically, when a child process exits,
it's no longer in the spotlight (it has exited).
handle this by having the parent process make the announcement after the wait call.
Buuuuuutt it ain't the child process that's printing the message, idk if this is wrong?
