Writing some perl Programs

jmc1987 · 11-19-2011, 11:51 PM

Well I feel I know most of the basics of perl but now I just trying to figure out some small perl programs I can write for practice and experience. So any that you guys recommend?

corp769 · 11-20-2011, 01:55 AM

Honestly, the best would be here - http://www.google.com/search?hl=en&s...1251l0.3.3l6l0
Not being mean about this either; The best would be to get online and follow many problems and exercises available freely.

Cheers,

Josh

jmc1987 · 11-20-2011, 10:03 AM

Quote:

Originally Posted by corp769

Honestly, the best would be here - http://www.google.com/search?hl=en&s...1251l0.3.3l6l0
Not being mean about this either; The best would be to get online and follow many problems and exercises available freely.

Cheers,

Josh

I actually did do a little bit of googling. I figured I would just ask here if anybody wanted a perl script that would be simple to do. And not being mean? What are you being mean about by saying google? LOL I tell people that all the time.

Sergei Steshenko · 11-20-2011, 11:19 AM

Quote:

Originally Posted by jmc1987

Well I feel I know most of the basics of perl but now I just trying to figure out some small perl programs I can write for practice and experience. So any that you guys recommend?

Write programs you need for yourself.

jmc1987 · 11-20-2011, 11:42 AM

Quote:

Originally Posted by Sergei Steshenko

Write programs you need for yourself.

Oh trust me I am. I am actually going to write a automated installer for all web services such as php, httpd, and build a simple user domain gui. If I do a good job I'll progress with it and actually release it.

corp769 · 11-20-2011, 09:05 PM

Quote:

Originally Posted by jmc1987

Oh trust me I am. I am actually going to write a automated installer for all web services such as php, httpd, and build a simple user domain gui. If I do a good job I'll progress with it and actually release it.

Or, you can start on it right now and make it your primary project, and then post your code here, and get second opinions and advice on it. Sounds like a feasible way to do it, and you might be able to learn a few more things that way too.

jmc1987 · 11-20-2011, 09:28 PM

Quote:

Originally Posted by corp769

Or, you can start on it right now and make it your primary project, and then post your code here, and get second opinions and advice on it. Sounds like a feasible way to do it, and you might be able to learn a few more things that way too.

Well if you insist I started but the names are going to change and stuff

PHP Code:



#!/usr/bin/perl 
#This Panel is licensed under GPL feel free to rebuild as your heart desires
#owPanel (Open Web Panel) is designed by James Carney

use strict;
use warnings;

print "\nWelcome to owPanel!\n";

my ($OS, $release, $version)=split(/\s+/,`cat /etc/*release*`);

if ($OS eq "CentOS"){
    if($version >= '5.7'){
    print "\nOperating System Requirements met!!\n";
    } 
}
else {
        print "\nERROR:  Operating System Requirements not met!!\n";
        print "Requied Operating System is CentOS 5.7 or Later\n";
        exit;
}
print "Check if Yum exsist!\n";
if (`ls /usr/bin|grep 'yum'`){
    print "Found Yum!\n";
} else {
    print "ERROR!!!  YUM is not installed!\n";
    exit;
}
print "Installing Apache\n";
print `yum -y install httpd,"\n";
print `chkconfig --levels 235 httpd on`;
print `service httpd start`;
print "Install Secussfull!\n";

update:

Changed my mind I'm going to build the web interface and let a bash script do on the service installs.

Sergei Steshenko · 11-21-2011, 06:43 AM

Quote:

Originally Posted by jmc1987

Well if you insist I started but the names are going to change and stuff

PHP Code:



#!/usr/bin/perl  
#This Panel is licensed under GPL feel free to rebuild as your heart desires 
#owPanel (Open Web Panel) is designed by James Carney 
 
use strict; 
use warnings; 
 
print "\nWelcome to owPanel!\n"; 
 
my ($OS, $release, $version)=split(/\s+/,`cat /etc/*release*`); 
 
if ($OS eq "CentOS"){ 
    if($version >= '5.7'){ 
    print "\nOperating System Requirements met!!\n"; 
    }  
} 
else { 
        print "\nERROR:  Operating System Requirements not met!!\n"; 
        print "Requied Operating System is CentOS 5.7 or Later\n"; 
        exit; 
} 
print "Check if Yum exsist!\n"; 
if (`ls /usr/bin|grep 'yum'`){ 
    print "Found Yum!\n"; 
} else { 
    print "ERROR!!!  YUM is not installed!\n"; 
    exit; 
} 
print "Installing Apache\n"; 
print `yum -y install httpd,"\n"; 
print `chkconfig --levels 235 httpd on`; 
print `service httpd start`; 
print "Install Secussfull!\n";

update:

Changed my mind I'm going to build the web interface and let a bash script do on the service installs.

In a sense it is not Perl.

For example,

Code:

if (`ls /usr/bin|grep 'yum'`)

is "tasteless" - you do not need to fork a child process (`...` does fork a child process) to check whether a file exists. Similarly, there is no error checking - theoretically 'grep' can become missing due to a screw up.

Code:

my ($OS, $release, $version)=split(/\s+/,`cat /etc/*release*`);

is not portable, and it's not worth it to write code only for CentOS.

Diagnostic output should better be printed to STDERR, not STDOUT.

All the above comments are not Perl specific. I've seen a sea of scripts like this. And, unfortunately, inheriting them from original authors I had to maintain them.

markush · 11-22-2011, 05:04 AM

Hi,

I've learned much at Project Euler http://projecteuler.net/index.php?section=about

Markus

bigearsbilly · 11-22-2011, 05:13 AM

I'm afraid you need to study a bit more.
No offence!

stuff like this really isn't pretty.

Code:

split(/s+/,`cat /etc/*release*`);

If you are printing error messages you should really use warn not print.

Also, this is possibly easier as a shell script.
Always use the best tool for the job.

jmc1987 · 11-22-2011, 12:48 PM

Quote:

Originally Posted by bigearsbilly

I'm afraid you need to study a bit more.
No offence!

stuff like this really isn't pretty.

Code:

split(/s+/,`cat /etc/*release*`);

If you are printing error messages you should really use warn not print.

Also, this is possibly easier as a shell script.
Always use the best tool for the job.

Yea I'm still learning best way to do things. Infact if you noticed where I edited my post days ago I stated that I'm discontinuing this project because I want to do the installs and stuff with a shell script and the actual web interface will be written in perl.