Types Of Files And Directory List In DOS

What is File?

A file is required to protect data, program, Software etc. Important data is kept in the computer in the same way as the different types of data and instructions are kept in general file.

Types of Files:
□ Program File
□ Data Files
□ Sub-Directory Files

Program Files: The extension names of these files are: Exe, Com, Bat, Sys, Bin etc. These files are part of software, which execute the operation system. Do not name data files with extensions .Exe, .Com, .Bat, .Sys or .Bin.
Data Files: Use data file for safe custody of any types of data in Hard Disk. Mostly .Txt or .Dat are the extension names of such files. These files are made by copy command or application Software for Dos.
Sub-Directory Files: These files are used to keep sub-directory safe. They are also used in the form of disk files.

File name

File name consists of two parts. First part is primary name containing maximum eight characters and minimum of one character and the second part is extension name which consists of maximum three characters and minimum of one character. Extension name is also known as secondary name, because it is not the essential part of file name. A Dot (.) is in between primary name and extension name, which combines or separates the both. Not two files of the same can exist in a directory.Points To Remember while Naming a File.

□ File should be named using alphabet A to Z or a to z and number 0 to 9 and specials characters like $, &, (,), #, -, @, %, !.
□ ?, *, \, /, [,], ., <, >, =, : sign are not allowed.
□ Following eleven words, which reserved word for DOS, should not be used while given file name: Com1, Com2, Com3, Com4, Lpt1, Lpt2, Lpt3, PRN, Nul, Con and Avn.
□ There should be no space between file name.
□ The extension name of file should be of maximum three characters.
□ Dot should be used to join primary name with the extension name of file.

Directory List

Use DIR command to see list of files in a directory.
Command : DIR
Type : Internal Command
DIR <Enter> or DIR [Switch] <Enter>

If you press Enter after typing DIR command, then all the contents of the present directory will appears before you in the form of a list. Here you can know whether the file in which you want to work is present in the directory or not.
You have to pay attention on the following information regarding the directory appearing as a result of DIR command.
Your directory label is seen in the first line. There is a name on the label, which you to identify any directory. Generally, you give this label at the time of formatting the disc. Disc Serial number is also shown in the in the second line. This serial number is also fixed at the time of formatting, but it is automatic and cannot be changed or altered or fixed by you.
Directory name is shown in the third line.
After this, list of files along-with their details are given below in five columns.
Following are the details of each column:
First Part: In this part, file or sub-directory name is shown.