how much of dos is incorporated in linux ,1 notice a lot of discussion regarding dos lines and I dont want to start that trip again ,if once set up it functions in a similiar fashion as windows it would be ok ,why go the same route twice ,dos was an error made by ibm ,a bit like the first plough

By "DOS", I assume you mean the command line. You can probably get away with not using it, but it's useful and using commands can get some things done more quickly (and more easily in some cases).

All of a gui OS is simply a hidden CLI, no matter what OS you are using, With any OS it would be more efficient to enter commands directly from the command line rather than clicking on a GUI interface. You don't have to use the command line in Linux, but it's a helluva lot easier to explain than trying to express in writing the process of accomplishing the same thing via a gui interface.

Generally speaking, Linux users are expected to know a little bit about the way their computer works, not just a simple minded, even brain-dead, process intended to keep them from that knowledge.

If you have such disdain for the CLI, stick with windows like all the other folks who choose to intentionally remain dummies.

dos was an error made by ibm ,a bit like the first plough

The term DOS is rather general. To what particular aspect of DOS are you referring to? I personally think it was pretty damn good for the time. Looking back with hindsight there were quite a few problems compared to what we have today. For example:

1) No memory protection (but bear in mind when DOS was released, the target processors didn't support for this)
2) Single task support (can you imagine trying to implement multitasking without memory protection?) And it did have TSRs but they were nothing more than crashes waiting to happen because of 1)
3) No I/O protection (you couldn't take i/o ports away from programs because DOS didn't provide a driver framework). Didn't really matter anyway because of (2)
4) Lazy programmers (DOS gave the the programmers kernel level control of the system, lazy programmers did things they didn't really have any rights to do, and very often didn't leave the system in the state they found it - that isn't really DOS's fault though)
5) Backwards compatibility (DOS ran on anything from an 8086 to high class pentium) Do you know how different these systems are? Neither DOS nor its programs could use the new features and remain backwards compatible, you might want to read about thing like unreal mode and the A20 address line as ways to get around this)

Most of those problems wouldn't be problems if DOS was only used for what it was designed for. Unfortunately, DOS was used way past its limits, and for commercial backwards compatibility reasons, it still loaded up in real mode with the A20 address line disabled.

However, I don't think any of these problems exist in any modern operating systems, certainly not Linux. So why do you think moving to Linux is like moving back to DOS? It is not even vaugely similar. Unless you are referring to the CLI aspect, but every modern operating system has a CLI, and Although not very experienced with it, I would say the Windows NT/2k/XP/... CLI is much more powerful and advanced than the DOS one.

That was pretty insightful, but I think he was referring to the command line.

If you browse through this forum you will get the impression that almost everything is being done on the command line - because like someone else said, it is much easier to tell someone to copy and paste a command than to make dozens of clicks. The clicks will change, the command will most likely stay the same.
But for the most part you don't have much to do with the command line. Once you need help, and someone gives you a command to type, just copy and paste it. It's really the easiest way to help.

Though obviously you need to understand what it does!

hmm...
Yes, but most of them are pretty self... explanatory...

Ok, no they are not. But you will get it pretty quickly.

By this I suppose you're referring to the 90+% of computer users who just want to surf the 'net, send & receive email, etc. No doubt it will surprise you, but some of these people are extremely well educated and intelligent (not always the same thing, admittedly), with limited interest in computers. Not everyone wants to be an All-Knowing Debian Smartass.

P.S.
I used the American spelling "ass" to make it easier for you to understand.

My sense is that we have given OP a bit more that he/she asked for....

In a quick skim, one thing I missed was what I have understood to be the history---namely that DOS was derived from Unix. Hence Linux is simply coming full circle.

As already stated, the command-line is a handy thing to know. In Linux, many things are easier at the CLI. One tragedy of Windows is the layers of "fluff" which protect the average user from ever typing a command. (Sometimes protect them form thinking, for that matter.)

I rather think Dos was invented for a single user in a 8086/8088 personal computer when Unix was already being used on the mini size mainframe computer serving multi-users.

To me Linux is a "forced" conversion of Unix to suit the hardware of PC.

The command lines in Linux is much more powerful than Dos. I rather think the OP lack the exposure to both Dos and the CLI in Linux and as a typical Windows user dismisses everything that cannot be clicked. Like richk said before if a user understands all desktop icon, commands and menus are made from terminal commands he/she may have a lot more respect for command line interface. Anybody who write a computer program, a script, a batch file, a macro etc will instantly know even 1000 different commands and tasks can be condensed/controlled by issuing one command in CLI. Not using CLI is not using at least half what a PC can do for us, regardless if it is a Dos or Linux Bash terminal.