Originally posted by zhangwencheng at 2009-2-15 02:32:
dos与linux近年发展的比较
Linux诞生于20世纪的90年代初，于90年代末开始出名并在许多人中开始了实际使用。著名的“开放源代码”运动更是使新的L ...
我也是从dos时代过来的，但是觉得222楼转的文章实在太误导，看得出作者确实对dos很熟悉很热爱，但是既然这个帖子讨论Linux，那么我也想评论一下。
“DOS软件的数量相当庞大，少说也有几十万个（比如DOS病毒就有4万多种）“
连病毒都成为骄傲了么？这我还真是第一次听到这种言论。
病毒多只能说明一点：dos毫无安全性可言。
“DOS是最适合于个人用户的，不仅要求低，实用性强，而且它的总体功能并不比Linux差。“
这里把Linux认为是广义上的某个Linux发行版，否则单是比较内核的无所谓“功能”。
不比图形界面，否则就是欺负dos了。
但是比命令行，那就更是欺负dos了。unix/linux的命令行功能之强大，绝非dos可比。看看shell programming自可理解。
比应用软件的话，我不知到那个作者说的“少说也有几十万个”是否有据可考，对于Linux，以gentoo为例子，portage树中目前超过10000个软件包。这些软件几乎涵盖了你能想象到的所有用途。
最欺负人的是，1. linux下可以安装一个虚拟机来模拟dos，反过来可不行。2. 新机器无法物理安装dos，即便安装上了（比如freedos），驱动你也搞不定。
“霸王枪——内存管理“
Linux可管理超大的内存（64G，甚至更多），dos还在玩段式管理吧？
“大家通常所使用的Windows 9x也只是DOS下的一个大型程序罢了“
Windows9x使用dos作为一个bootloader，但是不能说只是dos下的一个大型程序（只能这么说win3.x）。
“Windows是一个多任务的操作环境，但它对程序编写的约束和限制比DOS高得多“
必须要对程序做出约束和限制，这正是一个操作系统应该做，而dos没有能做到的一件事情（因为有人认为，dos不能算是一个严格意义上的操作系统）。传统DOS允许APP直接操作硬件，对于进程也没有太多的内存管理（装入内存，做一个跳转，剩下的全靠APP自觉），所以稳定性极差，安全性全靠自觉。Windows目前的安全已经算是不错了，当然这方面Unix/Linux更好一些。
我读过Linux 2.4kernel的内存管理源码，那真是面面具到，设计的相当精美。和dos这种啥都不管的系统，完全不在一个档次上。
总之，我个人不认为dos（不管是哪种，哪怕是最新的freedos）能有任何一方面可以媲美Linux。
当然DOS还是有用的，尤其是那些用Windows的人，系统出了大问题的时候偶尔可以用Dos来修复一些问题。
对于Linux用户，我只能说，Dos是没有用的，因为Linux各方面都优秀的多。
Originally posted by zhangwencheng at 2009-2-15 02:32:
Comparison of the recent development of DOS and Linux
Linux was born in the early 1990s of the 20th century, became famous at the end of the 1990s and began to be actually used by many people. The famous "open source" movement has made new L...
I also came from the DOS era, but I think the article transferred by building 222 is really misleading. It can be seen that the author is indeed very familiar with and loves DOS, but since this post is discussing Linux, I also want to comment.
"The number of DOS software is quite large, at least hundreds of thousands (for example, there are more than 40,000 DOS viruses)."
Is even a virus being taken as something to be proud of? This is really the first time I've heard such a statement.
The large number of viruses can only indicate one thing: DOS has no security at all.
"DOS is the most suitable for individual users. It not only has low requirements and strong practicality, but also its overall functions are not worse than Linux."
Here, Linux is considered as a certain Linux distribution in a broad sense; otherwise, there is no such thing as "function" when just comparing kernels.
Don't compare the graphical interface, otherwise it's bullying DOS.
But comparing the command line, it's even more bullying DOS. The command line functions of Unix/Linux are extremely powerful, far beyond DOS. You can understand it by looking at shell programming.
In terms of application software, I don't know if the author's statement "at least hundreds of thousands" is verifiable. For Linux, taking Gentoo as an example, there are currently more than 10,000 software packages in the portage tree. These software almost cover all uses you can imagine.
The most bullying thing is, 1. You can install a virtual machine under Linux to simulate DOS, but the reverse is not possible. 2. A new machine cannot physically install DOS. Even if it is installed (such as FreeDOS), you can't handle the drivers.
"Overlord Spear - Memory Management"
Linux can manage extremely large memory (64G or even more), while DOS is still playing with segment-based memory management?
"The Windows 9x that everyone usually uses is just a large program under DOS."
Windows 9x uses DOS as a bootloader, but it cannot be said to be just a large program under DOS (this can only be said about Win 3.x).
"Windows is a multitasking operating environment, but it imposes much higher constraints and restrictions on program writing than DOS."
It is necessary to impose constraints and restrictions on programs. This is something that an operating system should do, and something that DOS has not been able to do (because some people think that DOS cannot be regarded as a strictly operating system). Traditional DOS allows APPs to directly operate hardware, and there is not much memory management for processes (loading into memory, making a jump, and the rest is all up to the APP to be self-conscious), so the stability is extremely poor, and security is all up to self-consciousness. Windows' current security is already considered good. Of course, Unix/Linux is better in this regard.
I have read the source code of the memory management of Linux 2.4 kernel. It is really comprehensive and designed very exquisitely. It is completely not at the same level as a system like DOS that cares about nothing.
In conclusion, I personally don't think that DOS (no matter which one, even the latest FreeDOS) can be comparable to Linux in any aspect.
Of course, DOS is still useful, especially for those who use Windows. When the system has major problems, occasionally you can use Dos to repair some problems.
For Linux users, I can only say that DOS is useless because Linux is much better in all aspects.
