Expand, Fasthelp, Fc command usage

Expand decompression tool

[Applicable] Microsoft's original software installation disk contains many compressed files suffixed "_".
Decompress the package to relieve the trouble caused by the loss of a few files.

[Usage] expand [source file name] [target file]

[Example] C :\> expand a: vsafe. co _ c: \ dos \ vsafe.com

Decompress vsafe. co _ as the vsafe.com file.

Microsoft (R) File Expansion Utility Version 2.10
Copyright (C) Microsoft Corp 1990-1993. All rights
Reserved.

Expanding a: vsafe. co _ to c: \ dos \ vsafe.com. a: vsafe. co _:
33046 bytes expanded to 62576 bytes, 89% increase.

C: \ DOS>

Fasthelp quick display of help information

[Suggestion] You can check all the commands. For a single command, it is better to add/after the command name /? Parameters
Convenient

[Usage] fasthelp lists the usage of all DOS Commands

Fasthelp [command name] shows the usage of a command, which is equivalent to [command name]/?

Fc file comparison

[Suggestion] It may never be used by most people.

[Usage] fc [file name 1] [file name 2] compares the differences between the two files
The parameter is also a c l Lbn n t w nnnn.

[Example] C: \ TEST> fc a. bat B. bat
Comparing files A. BAT and B. BAT
* ***** A. BAT
Choice/c: dimethyl defrag, mem, end
If errorlevel 3 goto defrag
If errorlevel 2 goto mem
If errotlevel 1 goto end
* *** B. BAT choice/c: dimethyl ether defrag, mem, end
* *** C: \ TEST>