Free paid version software for linux

pvswitch is a very tiny program which makes it possible to use different program installations on one machine flawlessly.
Its flexibility is intended for people who need to run programs against different interpreter versions.
But it can also be used for different purposes like switching the version of a compiler, text editor, mail reader, browser, whatever.
It is most useful for developers of interpreter based programs which are started via a hash-bang line (#!).
The following example explains the usage for perl programs, but the very same is true for all other interpreter languages.
If you install two or more different perl versions on your machine, you could just call the respective perl binary you want to use..
perl myscript.pl
/path/to/another/perl myscript.pl
This works fine, although it isnt very convenient. However if you are starting your program using the hash-bang line like
#! /usr/bin/perl
and then just start it by
./myscript.pl
you would need to change the file itself to use another perl version. Again it is possible, but not very convenient.
And here comes pvswitch: its purpose is to make such situations convenient. Further it solve some problems which come up if multiple people want to use different perl versions. pvswitch allows even to run one program in two shells with different perl versions.
This is possible because pvswitch uses a environment variable to select the interpreter version to use. This environment variable can be set in different sessions independently.
pvswitch is installed as new program binary (e.g. perl) the old one will be renamed to program.pvswitch.
Now every time you execute a this program (e.g. perl), pvswitch is executed. It doesnt matter how you start the program...
perl myscript.pl
./myscript.pl # if it has a hash-bang #! /usr/bin/perl
for both cases the pvswitch binary will be executed, pvswitch will than check for the environment variable PVSWITCH_PERL_BINARY (if you are running perl), if it is found it tries to find this key in the configuration file pvswitch.conf and execute the program which is configured for the version configured set in the environment variable (e.g. perl.pvswitch).
So it just executes the real program (e.g. perl interpreter). Depending on the environment a different version might be selected.
There are some convenient tools (e.g. perlver, pvconfig) to configure this.
Enhancements:
- Fixed a bug which could cause segmentation violation.

Since I am the person who manages the money for our house, I need an efficient way to keep track of our expenses and an easy way to calculate who owes what to whom at the end of the month. There are lots of good free software utilities for managing money like GnuCash, KMyMoney and the wonderful Gnumeric spreadsheet. I had been using Gnumeric to manage the money for the last 8 months, but now that we have some people staying at the house for just the summer, and other leaving and coming back in September, the spreadsheet was not able to adjust to these irregular circumstances.

The reason I decided to write my own application from scratch instead of using an already existing money management application was because my problem is multi-person orientation and most (if not all) of the money management programs I have tried are single-person oriented. For example GnuCash will let you setup accounts that show you all the money moving to and from a single person. But in my house things like food are paid by any person and shared by every other person. Thus to efficiently and easily calculate who owes how much, it must take into account the fact that one pizza may be paid for by one person, but it was eaten by 4 people. Also I dont want to have to divide up the amounts myself and put it into GnuCash with multiple accounts, because then I might as well be doing it on paper.

I could have spent my time learning to make an already existing application do exactly what I want; and I probably would have found something pretty close. But I decided that it would be faster to just program it from scratch and then I would be sure I would get exactly what I wanted. I think I was right; it took less then 2 weeks to finished writing this program.

The program is currently called Adventure Money, but if anyone can think of a better name for it let me know and Ill gladly change it.

When you first launch the program you will see it has five views, all of which can be seen in the screenshots below.

A Simple Version Control System is an easy to install and easy to to use version/revision control system.
ASVCS differs from most other version control systems in that ASVCS is designed to keep track of files in place. ASVCS does not allow any changes to be made to files, all changes require the users to change files externally with FTP or SSH access.
ASVCS is very easy to setup and use. Users do not need to work with repository, branches, commit and check-out files. All a user needs to do is upload the changes files and click Update or if enabled just wait for it to be updated automatically.
ASVCS is ideal for small projects or personal use, though it can also be used by large project how do not need or want the complexity of most version control systems.
Main features:
- asy to install and use
- Written in PHP
- Can track binary or text files
- Automatic file tracking (requires cron support)
- Diffs of revisions
- Easy user access management
- Entirely Web based
- Skinable
- Open source (MIT/expat license)

bandwidth monitor is a small application which polls /proc/net/dev for the byte counts for a given network device , and calculates the RX and TX bandwidths. Originally a shell script, then a Perl script, now rewritten in C so that it can easily be used on embedded devices like the Linksys WRT54G as well as.

This program started as a shell script that I ran on my home-brew firewall wireless router (Linux, of course, on a 486/66) to keep track of my incoming and outgoing bandwidth. This let me know that I was getting the bandwidth that I paid for, and it also helped me keep an eye on the throttling of bulk traffic so that I didnt choke out my interactive sessions. Of course, that was before I had QOS.

The program is probably tied to Linux, since it grabs the byte counts for the requested interface right from /proc/net/dev. It could pretty easily be modified to grab the same information from the output of /sbin/ifconfig, but that would waste resources to spawn a new process to parse the /proc/net/dev file and regurgitate it to us. Also, I havent bothered to look at how uniform the output of the byte counts from /sbin/ifconfig is on other operating systems.

As a side note, the C version also uses nanosleep() and gettimeofday() to get more accurate polling intervals and track the overall time (since sleep(), usleep(), nanosleep(), et. al. only guaruntee to wait at least as long as you request, but do not guaruntee that it wont be possibly much longer...) So, if you were interested in porting it, youd have to make sure that nanosleep() and gettimeofday() were also available, or lose the resolution of the time used in bandwidth calculations.

BUILDING

$ gcc -O3 -o bandwidth_monitor bandwidth_monitor.c

PayVeX project works with PayPal IPN to sell files, this approach ensures you are paid for your digital content before a customer can download it.

For the customer using PayVeX, a purchase is quick, convenient, anonymous and simple.

In this day and age, asking for information can lead to lost sales. People are in a rush and arent interested in taking the time to fill out lengthy forms.

For the merchant, impulse buyers and people who would otherwise resist due to privacy or credit card concerns suddenly become buyers.

Space Mines project is a game where one makes money by building mines.
Space Mines is a game where one needs to make money by building mines and by keeping ones workers happy.
INSTALLATION
make all
make install
make clean
USAGE
Build mines (but not too many) and create profits by selling the ore!
You need to pay your workers wages to keep them happy. Mining on other worlds is a dangerous business, and workers are at risk from exploding mines, radiation leaks, etc.
Version restrictions:
- There is very little error checking for if someone enters the wrong data type (like letters where there should be numbers).
Enhancements:
- Decided to release it to the world
- Made it GPL
- Included some documentation

smspasswd software provides two factor authentication via cell phone short message service (SMS). The reason I wrote this was because of all the pesky SSH brute force attacks, which continue to build in numbers. I didn’t want to waste money and time on using tokens because the few people who have accounts on my machines also have mobile phones.

I’m stoked that I have been using this since v0.1 back in 2005 and so far it’s worked very well with no changes. I’m hoping for feedback to get me motivated to develop this some more. Thanks to my good friend Solomon who has encouraged me to start posting some of my fun projects on the web.
Any feedback is more than welcome to ed -at- e-things.org.

How does this work?

The simple explanation for the average user goes a little like this. You use your normal password followed by a 6 digit number. To get access to a system you need to send an SMS from your pre-registered mobile phone number with a PIN. The systems admin folk will assign you a 4 digit pin and give you the mobile number to send your login request to. So, when you want to login, just send a text (SMS) to the phone number provided, with your 4 digit PIN. Shortly after you will receive a 6 digit number in a text (SMS) to your phone. Then login as normal using you normal password followed by the 6 digit number. You can use this same 6 digit number as many times as you like within a time period set by the systems admin folk. Simple right? Ok then, perhaps not much more complex than a token?

Now for the spanner-head explanation. smspasswd is a Perl application that runs as a daemon. It uses a MySQL back-end database which stores the usernames, mobile numbers, PIN’s, passwords, tokens, and the amount of time each users token (temporary x digit code) is valid for. smspasswd uses the information in the MySQl database to update your LDAP server based on a polling frequency you set in it’s config file. You can also set lots of other options in the config file and these are covered in the Features section below. smspasswd talks to a SMS gateway to send and receive new token requests. In my case it’s a cheap pre-paid Nokia 7110 connected to COM1 (/dev/ttys0) via gnokii.

The authentication process goes a little like this. The user sends a SMS to your gnokii phone with their PIN. Note the PIN is not really important because it will get saved in the users SMS outbox, so it could just be “request” or “foobar”. What’s important is that the SMS must come from the correct number for that user, and even if this could be spoofed, the reply will still go the users mobile number in the database anyway. Then smspasswd checks the database for the users mobile phone number and if it finds a match it will send a x digit code to the number registered for that user. At this point the password for this user will be updated in the local LDAP server with their normal password, followed by their new x digit code. Once the user has the SMS with the new code they can login.

You should setup your systems and applications for LDAP authentication, and if you wish you can configure your FreeRADUIS server to authenticate via OpenLDAP. Or you can use some commercial LDAP or RADIUS system. FreeRADIUS and OpenLDAP work just fine for me.

Confused? Drop me an email and I’ll make a nice diagram with Dia.

Features

Here’s the config file, and check the source.


##################################################
# smspasswd config file
#
##################################################

# minumum password length
#
minPasswordLength 6

# minimum username length
#
minUsernameLength 2

# minimum PIN length
#
minPinLength 4

# database options
#
dbName smspasswd
dbUsername smspasswd
dbPassword [enter the database users password here]
dbHostname localhost
dbPort 3306
dbEncryptionKey [enter a very long and random string here]

# gnokii options
#
gnokii /usr/local/bin/gnokii
gnokiiMailBox IN

# Check interval. This is the amount of time to
# wait between incoming SMS checks in seconds as
# well as user timeout checks
#
checkInterval 15

# LDAP server option
#
ldapServer localhost
ldapBindDn cn=Manager,dc=yourdomain,dc=com
ldapPassword [enter your LDAP users password here]
ldapBiseDn ou=People,dc=yourdomain,dc=com

# Email notification for non pin request SMS messages
# This is very useful if you would like to be emailed
# the ‘your pre-paid account is about to expire’ messages.
# Note: PIN requests will not be emailed.
#
emailNotify yes
emailToAddress root@localhost
emailFromAddress root@localhost
emailSubject SMS notification from smspasswd