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Forking in Unix using C++


 
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# 1  
Old 06-04-2001
Question Forking in Unix using C++

i wanna ask about forking in unix...how can you do forking...??i don't understand and i have an assignment about it...the output should look like this...

Question 1 : what's your name ?
Answer : if no answer, write to file...----Out of time-----because for each question it is given a specific time to answer, if the user failed to answer it within the specified time, it prints out that message and output ---No answer--- on the question file( we have to read the questions from a file)...and there are 3 questions...the execution for this program should be....

$ a.out 5 question.txt

5 is the time specified and question.txt is the question file...it was taken in the line...

int main(int argc, char* argv[])
{...}
well, anybody can help me??please....
# 2  
Old 06-07-2001
Lightbulb

fork() is used to create a copy of a process. When you call fork(), the calling process is copied and you now have a parent and child process. THe only difference is the return value of fork(). It will return 0 to the child process, and a process ID number for the parent. That's how you can tell which process you're currently in.

Well, I won't write your assignment for you, but here's how a fork goes:
<pre>

int main(int argc, char* argv[])
{
pid_t pid;

printf("This will be seen once.");

pid = fork();

printf("This will get seen twice. Once for the parent, once for the child process");

if (pid == 0) /* This is the child process */
{
/* Do child process stuff here */
exit(0);
}
else if (pid < 0) /* Some sort of error in fork() */
{
/* Process error here */
}
else /* This means we are in the parent process */
{
/* Do parent process stuff */
wait(NULL); /* wait for the child to finish */
}
return(0);
}
</pre>
# 3  
Old 11-28-2008
This is not the place for writing homework for others!!
# 4  
Old 11-28-2008
Quote:
Originally Posted by steephen
This is not the place for writing homework for others!!
First of all, the post you're referring to is 7 years old. Good work there.

Second, did you even read the post you're chastising?

Quote:
Originally Posted by TelePlayer
Well, I won't write your assignment for you, but here's how a fork goes:
I gave the poster generic code for forking a process that he probably could have found anywhere else using a web search.

Thanks for the post, though. I am appropriately humbled.

-Joe

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