what is the differance between MS-DOS and UNIX ?  

Dos is windows operating system and cannot be used in networking, while unix is linux based operating system which can be used in networking.

Answered by Nisha at 6:36 PM on February 23, 2008

Unix and Windows(ms-dos) use completely different paradigms for run-time loading of code. Before you try to build a module that can be dynamically loaded, be aware of how your system works.

In Unix, a shared object (.so) file contains code to be used by the program, and also the names of functions and data that it expects to find in the program. When the file is joined to the program, all references to those functions and data in the file's code are changed to point to the actual locations in the program where the functions and data are placed in memory. This is basically a link operation.

In Windows, a dynamic-link library (.dll) file has no dangling references. Instead, an access to functions or data goes through a lookup table. So the DLL code does not have to be fixed up at runtime to refer to the program's memory; instead, the code already uses the DLL's lookup table, and the lookup table is modified at runtime to point to the functions and data.

In Unix, there is only one type of library file (.a) which contains code from several object files (.o). During the link step to create a shared object file (.so), the linker may find that it doesn't know where an identifier is defined. The linker will look for it in the object files in the libraries; if it finds it, it will include all the code from that object file.

In Windows, there are two types of library, a static library and an import library (both called .lib). A static library is like a Unix .a file; it contains code to be included as necessary. An import library is basically used only to reassure the linker that a certain identifier is legal, and will be present in the program when the DLL is loaded. So the linker uses the information from the import library to build the lookup table for using identifiers that are not included in the DLL. When an application or a DLL is linked, an import library may be generated, which will need to be used for all future DLLs that depend on the symbols in the application or DLL.

Answered by sujata at 6:03 PM on February 22, 2008

The main difference between UNIX and MS-DOS is that MS-DOS was originally designed for single-user systems, while UNIX was designed for systems with many users. While PC's have evolved into GUI interfaces such as Windows, UNIX systems have never evolved into GUI environments (Of course UNIX code evolved in to Linux GUI). UNIX has a richer command set than MS-DOS. UNIX is more secure than MS-DOS as there are 2 levels at which security is given in UNIX,both at login level and file level. Everything in UNIX is treated as file (even the hardware devices) but it is not the case in MS-DOS systems.

Answered by A.R.Karthick at 3:23 PM on February 22, 2008

Well Dharmik, Although Unix and DOS both are based on CUI ( Command line user interface), they differ in a big way and similarities are also there .

Well UNIX and MS-DOS have much in common, primarily because MS-DOS was partly developed using ideas from UNIX. Here are some of the major differences:

1) UNIX filenames are arbitrary strings of up to 255 characters, MS-DOS filenames are limited to an 8 character file name and a 3 character file type, and have restrictions on allowable characters.

2) UNIX doesn't require the notion of a disk drive modifier for a file specification, i.e., you don't need A:, B:, C:, and so on like MS-DOS. Note that MS-DOS has the JOIN command which can simulate the UNIX file system.

3) UNIX uses forward slashes (/) to separate directories in a file specification, whereas MS-DOS uses backslashes ( tex2html_wrap_inline1317 ).

4) UNIX is a full multiuser multitasking operating system, whereas MS-DOS is a single-user OS without concepts like file-ownership and process priorities.

5) UNIX has a richer command set than MS-DOS.
6) UNIX and MS-DOS both have the concept of a PATH.

7) UNIX and MS-DOS both have pipes and I/O redirection.
8) UNIX displays characters on your terminal as you type them, regardless of whether the operating system is ready to accept a command. MS-DOS will buffer, but not display, terminal input when it is busy executing the previous command.

9) MS-DOS programs generally have a nicer user interface than traditional UNIX ones. This situation is changing with the emergence of X-windows applications on UNIX.

To know more about the differences between other Operating system, Visit the source site :

http://www.phys.unsw.edu.au/~m cba/newunix/node24.html

Answered by alokgupta14 at 2:24 PM on February 22, 2008