Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Need explanation on Perl Fork
Top Forums Shell Programming and Scripting Need explanation on Perl Fork Post 302786357 by technoman on Wednesday 27th of March 2013 09:48:11 AM
Old 03-27-2013
Elixir i have question too ... by wat u explained ..suppose if i want to run a date command on ten remote nodes i should place my command here ?


Code:
#!/usr/bin/perl
use strict;
use warnings;
print "Starting main program\n";
my @childs;
for ( my $count = 1; $count <= 10; $count++) {
        my $pid = fork();
        if ($pid) {
        # parent
        #print "pid is $pid, parent $$\n";
        push(@childs, $pid);
        } elsif ($pid == 0) 
            {
                 */ Does the remote command go here /*

                exit 0;
             } 
           else {
                die "couldnt fork: $!\n";
        }

}
 
foreach (@childs) {
        my $tmp = waitpid($_, 0);
         print "done with pid $tmp\n";
 }
 
print "End of main program\n";

Last edited by Corona688; 03-27-2013 at 12:46 PM..
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

new to perl.. how do I do this ? fork/ threads ?

I have never coded in perl before (just started today morning :). I need to write a perl program to automate a task. Here is how I do it manually: Start a program in my home dir. Now if I want to execute another program while this one is still running, what I would do is go to another... (6 Replies)
Discussion started by: the_learner
6 Replies

2. Shell Programming and Scripting

tr explanation please

how does below tr command replace nonletters with newlines? I think I understand tr -cs '\n' part.. but what is A-Za-z\' <--- what is this?? tr -cs A-Za-z\' '\n' | -c --complement -s, --squeeze-repeats replace each input sequence of a repeated character that is... (0 Replies)
Discussion started by: convenientstore
0 Replies

3. UNIX and Linux Applications

need explanation

Hi am having a c pgm. It has the include files (unistd.h,sys/types.h,win.h,scr.h,curses.h,stdarg.h and color.h). I don't know the purpose of these include files. will u plz explain me. (1 Reply)
Discussion started by: Mari.kb
1 Replies

4. Shell Programming and Scripting

Perl fork

Hi, I want to exec three different functions in perl one per fork(); How can I determine that this it the third fork and I should use third function in it. if ($pid = 0) { first();} else ( #parent second(); ) How to run third function? (1 Reply)
Discussion started by: mirusnet
1 Replies

5. Shell Programming and Scripting

Need explanation on Anonymous hash in PERL!!

Hi, I have doubt regarding the Anonymous hash. For creating a object we are generally using Anonymous hash. My Doubt is: Why we are only using Anonymous hash?? Instead of Anonymous hash can we use global hash variable and take its reference for creating an object using same bless function??... (0 Replies)
Discussion started by: jatanig
0 Replies

6. Homework & Coursework Questions

Please help with the following fork code..with complete explanation

I have the following piece of codes. Please explain it to me in great detail how are these codes working. 1. #include <stdio.h> int main(){ int x; x=0; while (x<2 && fork()){ if (!fork()) execlp("echo","x++","x",0); x++; system("echo x+x"); } } 2. #include <stdio.h> int i;... (1 Reply)
Discussion started by: prakashabii
1 Replies

7. UNIX for Dummies Questions & Answers

In need of explanation

Its great someone provided this script that strips out a filename and extension but can someone explain how each line works? file1='Jane Mid Doe.txt' newfile='Jane.txt' 1) ext=${file1##*.} 2) filename=${file%%.???} 3) set -- $filename 4) newfile="1.$extension" (1 Reply)
Discussion started by: Lillyt
1 Replies

8. Shell Programming and Scripting

fork in perl

Can someone tell me perl fork example please. I tried online but could not get proper documentation. (2 Replies)
Discussion started by: Anjan1
2 Replies

9. Shell Programming and Scripting

fork in perl

Hi, I have a file which has some 50 hosts, I want to login to each host using ssh and execute any command. I am using fork function in perl. I am able to login to each host and execute the command in the hosts paralelly, but it spawing/forking 50 processes at a time. It will consume the cpu... (5 Replies)
Discussion started by: Anjan1
5 Replies

10. Shell Programming and Scripting

Perl scripts: requesting for logic explanation

Hi, balajesuri and durden_tyler, I have found your perl script for the thread https://www.unix.com/shell-programming-scripting/176370-perl-script-help-me-extracting-string.html, but find it difficult to understand the syntax. Could you or any forum members kindly shed some light on the logic... (3 Replies)
Discussion started by: royalibrahim
3 Replies

LEARN ABOUT HPUX

lamnodes

LAMNODES(1)							     LAM TOOLS							       LAMNODES(1)

NAME

       lamnodes - Resolve LAM node/CPU notation to Unix hostnames.

SYNOPSIS

       lamnodes [-chin] [where]

OPTIONS

       -c	   Suppress printing the CPU count for each node.

       -h	   Print the command help menu.

       -i	   Print IP addresses (instead of IP names)

       -n	   Suppress printing CPU count for each node

DESCRIPTION

       The  lamnodes command is used to resolve LAM node/CPU nomenclature to Unix hostnames.  It can be used to determine the current running con-
       figuration of the LAM/MPI run-time environment, and generate a boot schema that can be used to launch LAM in the future.

       By default, lamnodes will print out the node number, default IP name, CPU count, and per-node flags for	each  node  in	the  running  LAM.
       gethostbyaddr(3) is used to obtain default hostnames.  If gethostbyaddr(3) fails, the IP number is displayed instead.

       This  command  can be used by setup shell scripts (and the like) to determine information from a currently-running LAM universe.  For exam-
       ple, use lamnodes to resolve particular CPUs and/or nodes to specific unix hostnames.  In a batch environment,  lamnodes  can  be  used	to
       determine which CPUs share a common node (note that MPI_GET_PROCESSOR_NAME can be used for a similar effect in an MPI program).

       lamnodes also shows per-node flags.  Currently defined flags are:

       origin	   The node where lamboot was executed.

       this_node   The node where lamnodes is running.

       no_schedule The node will not be used to run MPI and serial processes when N and C are used to mpirun and lamexec.

EXAMPLES

       lamnodes N -n
	   Display IP names and CPU counts for all nodes.  This output can be saved and later used with lamboot(1).

       lamnodes C -n -c
	   Display  the  IP  name  of the nodes containing each CPU, and suppress the LAM node number and CPU count.  This output can be saved and
	   later used with lamboot(1).

SEE ALSO

       bhost(5), gethostbyaddr(3), lamboot(1)

LAM 7.1.4							    July, 2007							       LAMNODES(1)
All times are GMT -4. The time now is 03:42 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy