programming language: c

Write a program that calls fork(). Before calling fork(), have the main process access a variable (e.g., x) and set its value to some- thing (e.g., 100). What value is the variable in the child process? What happens to the variable when both the child and parent change the value of x?

Write a program that opens a file (with the open() system call) and then calls fork() to create a new process. Can both the child and parent access the file descriptor returned by open()? What happens when they are writing to the file concurrently, i.e., at the same time?