UNIX Programming and Technical

Q. How can you get/set an environment variable from a program?

A. Getting the value of an environment variable is done by using `getenv()'.
Setting the value of an environment variable is done by using `putenv()'.

Read Solution (Total 0)

UNIX Other Question

Q. Predict the output of the following program code

A.
main()
{
fork();
printf("Hello World!");
}
Answer:
Hello World!Hello World!
Explanation:
The fork creates a child that is a duplicate of the parent process. The child begins from the fork().All the statements after the call to fork() will be executed twice.(once by the parent process and other by child). The statement before fork() is executed only by the parent process. Q. How can a parent and child process communicate?

A. A parent and child can communicate through any of the normal inter-process communication schemes (pipes, sockets, message queues, shared memory), but also have some special ways to communicate that take advantage of their relationship as a parent and child. One of the most obvious is that the parent can get the exit status of the child.