10 More Discussions You Might Find Interesting
1. Programming
I understand that fork create a child but I need very simple example that make child useful....
I mean how will make the program faster anyone explain with code plz
using C plz (2 Replies)
Discussion started by: fwrlfo
2 Replies
2. UNIX for Dummies Questions & Answers
I'm trying to run a simple test on how to use fork(), i'm able to execute the child process first then the parent, but how can I execute parent then child..?
Thanks! (1 Reply)
Discussion started by: l flipboi l
1 Replies
3. Programming
Hello people.
I'm trying to do something like a search engine.
Server runs in the background by using ./server & which has data from a textfile stored in an array.
Client then runs by using ./client
It will then prompt "Search for:"
For example, if I searched for Products called Instant... (0 Replies)
Discussion started by: andylbh
0 Replies
4. Programming
I need to write a program which creates some n number of processes first and also creates a fifo for each of them, then it connects to the server and..
I tried creating these processes with fork() in a for loop but it doesn't print out what i write inside the child..
for(int count = 0; count... (7 Replies)
Discussion started by: saman_glorious
7 Replies
5. Programming
Hi everybody,
I wanna write a code to understand how fork works.
my target
--------------
-Parent creates a file(called temp) and writes into this file "1".Then it closes the file.
-Then parent creates a child and wait until execution of this child ends.
-Then child opens the same... (3 Replies)
Discussion started by: alexicopax
3 Replies
6. Programming
hi all
About this code
for (i = 1; i < n; i++)
if ((childpid = fork()) <= 0)
break;
I really can't understand the output .
and the way fork () return the value .
how about the process Id ,the child process Id and the parent ID
in this case
so please answer me soon (5 Replies)
Discussion started by: iwbasts
5 Replies
7. Programming
hello,
Every time i use fork() in the for loop, my college network(which i work in) either gets slow or hangs up.Can any 1 explain why it is so?
Of course there is no use of doing it though. But still i want to clear my doubt.
Thanks (2 Replies)
Discussion started by: cyno
2 Replies
8. Programming
I run this code, actually I want to both processes print the message from "data". But only one does. What happens? Anyone can help?
#include <stdio.h>
main(){
int fd, pid;
char x;
fd = open("data",0); /* open file "data" */
pid = fork();
if(pid != 0){
wait(0);
... (2 Replies)
Discussion started by: Herman
2 Replies
9. Shell Programming and Scripting
I need a quick script that will serve as a sort of "real time monitor" for watching some log files. I am using Bourne shell in HP-UX 10.20. I have basically created a script that never ends, unless of course I manually terminate it. Here's the script (it's called qhistory):
clear
echo "REAL... (3 Replies)
Discussion started by: cdunavent
3 Replies
10. UNIX for Dummies Questions & Answers
What is a fork? Why would one create a fork? What are the advantages and disadvantages of using a fork?
Please advise.
Thank You.
Deepali (5 Replies)
Discussion started by: Deepali
5 Replies
IO::Async::Loop::Select(3pm) User Contributed Perl Documentation IO::Async::Loop::Select(3pm)
NAME
"IO::Async::Loop::Select" - use "IO::Async" with "select(2)"
SYNOPSIS
Normally an instance of this class would not be directly constructed by a program. It may however, be useful for runinng IO::Async with an
existing program already using a "select" call.
use IO::Async::Loop::Select;
my $loop = IO::Async::Loop::Select->new;
$loop->add( ... );
while(1) {
my ( $rvec, $wvec, $evec ) = ('') x 3;
my $timeout;
$loop->pre_select( $rvec, $wvec, $evec, $timeout );
...
my $ret = select( $rvec, $wvec, $evec, $timeout );
...
$loop->post_select( $rvec, $evec, $wvec );
}
DESCRIPTION
This subclass of "IO::Async::Loop" uses the select(2) syscall to perform read-ready and write-ready tests.
To integrate with an existing "select"-based event loop, a pair of methods "pre_select" and "post_select" can be called immediately before
and after a "select" call. The relevant bits in the read-ready, write-ready and exceptional-state bitvectors are set by the "pre_select"
method, and tested by the "post_select" method to pick which event callbacks to invoke.
CONSTRUCTOR
$loop = IO::Async::Loop::Select->new
This function returns a new instance of a "IO::Async::Loop::Select" object. It takes no special arguments.
METHODS
$loop->pre_select( $readvec, $writevec, $exceptvec, $timeout )
This method prepares the bitvectors for a "select" call, setting the bits that the Loop is interested in. It will also adjust the $timeout
value if appropriate, reducing it if the next event timeout the Loop requires is sooner than the current value.
$readvec
$writevec
$exceptvec
Scalar references to the reading, writing and exception bitvectors
$timeout
Scalar reference to the timeout value
$loop->post_select( $readvec, $writevec, $exceptvec )
This method checks the returned bitvectors from a "select" call, and calls any of the callbacks that are appropriate.
$readvec
$writevec
$exceptvec
Scalars containing the read-ready, write-ready and exception bitvectors
$count = $loop->loop_once( $timeout )
This method calls the "pre_select" method to prepare the bitvectors for a "select" syscall, performs it, then calls "post_select" to
process the result. It returns the total number of callbacks invoked by the "post_select" method, or "undef" if the underlying select(2)
syscall returned an error.
SEE ALSO
o IO::Select - OO interface to select system call
AUTHOR
Paul Evans <leonerd@leonerd.org.uk>
perl v5.14.2 2012-10-24 IO::Async::Loop::Select(3pm)