Concurrent Version System, or cvs, is a system for maintaining source code and other text-style files.

Multiple developers can 'check out' the files and edit them as they like. Then they can 'commit' their changes so they get visible to the other developers.

There is also publication tools, such as cvsup, built upon cvs.

Not mentioned is the fact that cvs (the concurent version system, not the drug store) is based on RCS. The main difference between the two is the fact that RCS uses a locking mechanism which allows only one user at a time to edit the sources. CVS will alow mutltiple users to edit the same revision of the sources, and then will try to merge them on commit.

"CVS" also stands for "Copyright Violation Squad," a group which had stations in various places across North America and made dub recordings available through the mail of various musical works deemed unacceptable by the thought police in America, Europe and Canada. These works included "U2" by Negativland, "Plunderphonic" by John Oswald, and something by the KLF ("Kopyright Liberation Front").

I don't know if they're active anymore or not... I rather suspect not. But you can download all of these forbidden items and more at Detritus.net -- your found sound and media reappropriation emporium!

I find it interesting how many different disciplines use the same acronyms. In the obstetrical field you will more often hear the acronym CVS than the full name of the procedure.

Chorionic Villus Sampling as a procedure is very well covered in this other node. The basics (so you will know if you do not want to look further) is that CVS is a form of obstetrical prenatal testing used to make a genetic diagnosis.

CVS allows the diagnosis of some genetic disorders very early in pregnancy. That is its advantage over amniocentesis as CVS and amnio basically diagnose the same genetic conditions.

Frequently when a woman is seeking genetic testing of her fetus it is with the intention to abort if the diagnosis is not the one desired. An abortion early in the pregnancy causes less maternal complications than an abortion later in the pregnancy.

Abortions performed after genetic testing can follow the diagnosis of conditions with extreme and unvarying mortality and morbidity, such as Tay Sachs disease to conditions with somewhat lessening mortality and morbidity such Cystic Fibrosis (as medical science improves outcomes). Genetic testing is also used to diagnose and often abort fetuses with even more controversical conditions, such as Down's syndrome. Prenatal genetic testing is even used for sex selection with fetuses of the undesired sex being aborted. Prenatal genetic testing is not always accurate. I have personally witnessed births of the "wrong" sex as well as "normal" infants who were diagnosed with genetic disorders during pregnancy.

CVS causes the loss of the pregnancy about 2% of the times it is used because of the invasive nature of the procedure.

Without even getting into the abortion debate, in my opinion it seems foolishly invasive to use the more dangerous procedure of CVS over amniocentesis if the intention is not a possible abortion but rather to know a diagnosis a little earlier. Sometime knowing a diagnosis prenatally can save the life of a child by allowing proper preparation for needed medical procedures immediately after birth but a few weeks to a month earlier do not matter for this particular rationale.

Concurrent Version System
Setting up local (non-client/server) CVS in Windows

Assuming you already have a the Windows version of the CVS client downloaded and installed on your PC, the following steps are necessary to get CVS to work from local:
C:\>mkdir c:\cvsrepository
C:\>mkdir c:\cvsrepository\CVSROOT
C:\>set CVSROOT=:local:c:/cvsrepository

Why would you bother with this? I am doing it because I'm on a Windows 2000 machine without access to a CVS server. Although I'm the only one working on the code that I'm writing I still wish to benefit from CVS's versioning so that I can follow the changes I make to my code.

(I would like to apologize for the ocassionally non-serious tone of this writeup. It does not represent my religious views. I am sorry if it is not helpful, because helpfulness was the intention behind this writeup.
ariels said this writeup is inadequate because ClearCase is *censored* not up to the task. I hope a separate writeup on that topic will appear later.)

Basic usage of CVS

Some introduction

Some terminology: Even when CVS uses file version numbers, just like RCS, you most likely don't need to care of these. The idea is that for each "release", you create a "tag". File revisions with the same tag are part of the same "release". More on this later.

Also, you have a "local copy" and the "repository". You can do whatever you want with the local copy - it is just bunch of bits. Edit it. Print it and make paper flowers out of it. Whatever. The code itself, and all of its past revisions, are stored in the repository - it may be local, or it may be on some separate server. It all depends on the case.

Also understand that this is a very brief guide - CVS has a pretty thorough manual and there was some book that is available for free on the web, but this one is a start.

I just want the get files from the "anonymous CVS server" thing!

This is what most "non-developers" who want to live on the bleeding edge want. (Warning: The developers often put the "stable" programs in easily downloadable tarballs for a good reason. =)

Typically, the Hymn "He Eats the Fruits of Distributed Development with Furiously Moving Fingers and Shredding Jaws" looks like this:

$ export CVSROOT="pserver:anonymous@cvs.example.net:/cvsroot/wherever"
$ cvs login
$ cvs checkout modulename

Now, on the other hand, if you are developing code, you may probably want to know how to do that! Read on...

Login and initial setup

First, you may need to set your CVSROOT variable and/or do cvs login. (Most of my code is either in local repository, or in SourceForge's ssh-armored repository - they have specific orders, and by default my CVSROOT variable points to the local cvs.) This all depends on the case. If you need to make a whole new repository, consult the documentation. =)

The Idea

The idea is that you make a working copy, make your changes, and check out the revision back to the repository, with comment explaining what you did.

Also note that if more than one people edit the file same time, CVS will warn about it, the conflicting code will be marked, and you need to settle that like real men/women. With fists and knives.

How your work day goes

Typically, you start the "work day" by typing something like this:

$ cvs checkout modulename
$ cd modulename

Alternatively, if you have it all copied already, you can do:

$ cd modulename
$ cvs update

As an end result, you should have an up-to-date copy of the code in the repository.

Now, code!

You can review the changes you have made by doing:

$ cvs diff

Each time you have completed a "working version", you may check out your work to CVS by saying:

$ cvs commit filename

...or, you can commit all files you have changed by leaving out the file name. Now, the thing will ask for change comments (and will pop into your favorite editor for that). Just type in some credible explanation, save and exit.

End your workday with a full commit (cvs commit).

File Management

Need to add files or directories? It's easy! Do cvs add filename. You probably will be again required to explain yourself.

Need to delete files or directories? the command is remove! (Note that whatever is removed is not removed from the repository entirely; The future may be gone, but history lives forever).

Need to rename files? Uh... er... this is where it gets clumsy! Remove and re-add. If you don't like this, wait for a non-Alpha release of Subversion or try a proprietary but nice competitor like BitKeeper something.

Tagging

Going for release? You must tag your releases. Like,

$ cvs tag release-1-0 .

This way, you can always ask for "Release 1.0" from the repository, even when you're working on 2.5 =)

CVS, known today as CVS/Pharmacy, is a large chain of convenience stores and pharmacies in the US. "CVS" is short for Consumer Value Store.

They sell a wide variety of merchandise, including greeting cards, medications, magazines, toys, food, beauty care, and appliances. That's all in addition to the 1-hour Photo Lab and Pharmacy. Many, but not all, store locations are open for 24 hours a day, including the pharmacy.

As of today, they have over 4,100 stores, 9 distribution centers, regional offices, PharmaCare headquarters, and their Store Support Center in Woonsocket, Rhode Island. They are in at least 34 states and most major cities. They are also the leading pharmacy in plenty of locations, beating out such competitors like Genovese and Eckard.

They also have an online pharmacy at CVS.com, for US customers. It's integrated into CVS' network, meaning customers can order medications online and pick them up at stores.

They have an ExtraCare program, where if you show your free CVS card, you earn 2% back on stuff (They give you cashback coupons, but you have to spend over that amount to redeem them). Also, they have their own CVS brand merchandise (medications, foods. Its cheaper than brand, but IMO just as good. Employees get 20% off store merchandise.

History

The first CVS opened in 1963 in Lowell, Massachusetts. They sold health and beauty products. In 1967, they began operating the first stores with Pharmacy departments. By 1970, they had opened 100 stores in New England and the Northeastern US.

Sales boomed, and by 1974, they reached the milestone of $100million US in sales. By 1980, they became the 15th largest pharmacy chain in the US with 408 stores and $414million in sales. They later hit the $1billion milestone in 1985.

In 1990, they acquired "People's Drug" which further expanded their markets. In 1994 they launched PharmaCare, "a pharmacy benefit management company providing a wide range of pharmacy management benefit services to employers and insurers."

In 1997, CVS bought the Revco pharmacy chain, the largest acquisition in the history of US pharmacy. That spread CVS's all over the US, which made it national. They also purchase existing pharmacies and turn them into a CVS. Their CEO came from a pharmacist at Arbor Drugs, Inc of Michgan.

By 2001, they had sales of over $24 billion and passed the 4,000 store mark. They plan on opening 440 new stores annually. According to their brochures, they're focusing on expanding in Central and South Florida (all those sick Senior Citizens!), Las Vegas, Phoenix, Dallas, and Houston.

By 2007 they merged with Caremark, a major insurance processing company, and acquired even more stores.

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