As you may know, MS DOS and UNIX platforms are similar in that they both function by using a command line system interface, relying on the user to input commands it can then execute. However, despite this chief similarity, they contain differences that are significant.

For instance, while UNIX is a multi-tasking, multi-user system that can run two programs at the same time, MS DOS is a single-user, single-tasking system. Their command scripts, though equivalent in function, both use different syntaxes. Moreover, both systems differ in the way in which they store text files, and hence, how they interpret them.

UNIX And MS DOS Text files

UNIX based systems, for instance, will store text files using a single Line Feed (LF) as a line terminator. The MS DOS system, by contrast, saves its text files with both a Carriage Return (CR) and a Line Feed (LF) character, resulting in each line of text ending with a CRLF character.

Naturally, these characters won't produce any problems when you view the text file on its native platform. After you perform a binary file transfer, however, it's a different story.

When MS DOS text files are opened within a text editor on a UNIX machine, you'll find that UNIX will interpret the LF character correctly, but won't recognize the CR line terminator. Instead, the Carriage Return will be interpreted as (^M) Ctrl-M characters appearing at the end of each line of text.

Why Make The Conversion?

As you can imagine, this difference in line terminators can frustrate textual data exchanges, cause errors for source code compilers, and complicate any other type of work that depends upon the use of text files.

One way to get rid of those pesky end-of-line (^M) characters quickly is to convert from UNIX to DOS. The iConv online utility can convert from UNIX to DOS format, performing the same function as the classic unix2dos converter found on Unix. All you need to do to get a clean MS DOS text file is upload your file and click on Convert.