UNIX for Dummies Questions & Answers

hi


I am new to unix.I have searched some forums but couldnt get my answer.
i have created 6 processes and i want to write the process ids into a file which can be read in another program i am writing.Can someone plz send me the syntax for doing so.


I have a doubt regarding pipes.If a pipe is created before a fork then i know that the parent and child process can communicate via this pipe.My question is whether i can declare a pipe after i have created processes and communicate between them.Is it possible to declare a single pipe to use between 6 processes(between 2 at a time and again resuing the same pipe for commnicating between another two).

I apologize if my questions sound lame but i completely new to this.Plz answer.....

I don't understand exactly what you're trying to do, but if you're writing a bash script, you can use the variable $$, which returns the process ID of the current process. If you run " echo $$ " from the command line it will always give you the process ID of your current bash session, but within a script it returns the process that script is running in. You can assign it to a variable or whatever.

If this doesn't help, please give a little more detail.

Thanks,
Shawn

int main()
{
int count;
pid_t fork_result;


for( count = 0; count < 3; count++ )
{
fork_result = fork();
if( fork_result == 0 )
printf("\n%d\n",getpid());
}
return 0;
}

This is my program which creates 7 processes though i need only 6.I want to copy these process id into a file which can be asseced in another program.but i'm unable to find the format for it.

Can you plz answer my pipe question in the above post.

You can redirect the output of your program to a file.

Code:

./program > file

Regards