Question

using the system and exit system calls , write a two independent programs, instead of a normal parent-child pairing. first write a program be called myRand doing the following: 1. Generate a new file name dataX.dat where X is a random number between 0 and 255. 2. Generate 60 values between 0 and 100 and store them in the file. 3. Exit with an exit status of X. The second program should do the following: 1. Use fork to create a child process and use one of the exec fuctions to run the myRand program. you can simply use wait or waitpid for this one; you don't need to write a signal handler for SIGCHLD unless you choose to. We need to use WEXITSTATUS to convert the status returned by wait to the actual value. 2. Open the file dataX.dat where X is the number returned from system. 3. Read the 60 values from the file, display them, compute their average, and output the average. 4. unlink the data file.

Answer 1

The program named `myRand` generates a new file named `dataX.dat` (where X is a random number between 0 and 255), stores 60 randomly generated values between 0 and 100 in the file, and exits with an exit status of X.

The second program, after using `fork` to create a child process, employs one of the `exec` functions to execute the `myRand` program. The parent program uses `wait` or `waitpid` to obtain the exit status of the child process. It then opens the file `dataX.dat`, reads 60 values from it, displays the values, calculates their average, outputs the average, and finally unlinks the data file.

Step-by-step explanation:

In the first program (`myRand`), the file name is generated with a random number X between 0 and 255. Sixty values are generated and stored in the file, and the program exits with an exit status of X.

In the second program, a child process is created using `fork`, and the `exec` function is used to run the `myRand` program. The parent program waits for the child process to finish and retrieves the exit status using `wait` or `waitpid`. The file `dataX.dat` is then opened, and its contents are read, displayed, and used to calculate the average of the 60 values. Finally, the file is unlinked to clean up.

This process allows for independent execution of the two programs, demonstrating the use of `system` and `exit` system calls along with `fork`, `exec`, and file I/O operations.