QuestionSelect all possible outputs of the given C program when run on a Unix system. Possible outputs include:
1. ABBDD
2. A A B C D
3. A B D C D
4. ACBDD
5. ABBCCDD
6. ACD
7. A B C D
8. A B C D D
Studdy Solution
STEP 1
Assumptions1. The code is written in C and is running on a Unix System.
. The function `fork()` creates a new process by duplicating the existing process. The new process, called the child, is an exact copy of the calling process, called the parent, except for a few values changed, including the process ID.
3. The function `fork()` returns a zero to the newly created child process and returns the child's PID to the parent process.
4. The function `wait(NULL)` makes the parent process wait until all of its child processes have finished.
5. The function `out(x)` will print x once in the standard output.
6. The execution order of parent and child process is not guaranteed.
STEP 2
Let's analyze the code and the possible outputs.
The code first prints 'A', then creates a child process. If the process ID is greater than0, it means we are in the parent process and 'B' is printed. If the process ID is equal to0, it means we are in the child process and 'C' is printed. The parent process waits for the child process to finish before printing ''. The child process also prints '' after printing 'C'.
STEP 3
Based on the code analysis, the possible outputs are1. 'A' is printed first by the parent process.
2. If the parent process continues execution before the child, 'B' is printed, then '' after the child process finishes. The child process prints 'C' and ''. So, the output can be 'ABDC'.
3. If the child process continues execution before the parent, 'C' is printed first, then ''. The parent process prints 'B' and ''. So, the output can be 'ACBDD'.
STEP 4
Let's compare the possible outputs with the given options.
1. 'ABDC' is not in the options.
2. 'ACBDD' matches with option4.
Therefore, the only legal and possible output that this program may produce if we execute it on a Unix System is 'ACBDD'.
Was this helpful?
