File Type In Linux

[Instant]

Windows depend on the extension of the file to decide its type:
.doc > Doccument
.bat > Batch File
.zip > Compressed File ...etc

What does Linux depend on to decide the type of the file?

Another Related Question:

in Windows u could save a test file as *.bat and it will work as command prompt
what should I save the text file in Linux so it would work as Terminal Program directly??

[bigtomrodney]

Nothing so primitive for Linux

You can use filetype associations, but ultimately the filetype is determined by a 'magic number'. If you look at shell scripts they always start with

#!/bin/bash

The #! is the file start and it indicates that the file is an executable script. It's the same for most dedicated filetypes. For example, take a jpeg and remove the .jpg extension - it will still be recognised that it is a jpeg because the start of the file already indicates that it is. It is the same for most files, the exception being when a file is just a generic text file; .html, .xml, .txt for example. In this case the file extension is helpful.

[Instant]

in Windows u could save a test file as *.bat and it will work as command prompt
what should I save the text file in Linux so it would work as Terminal Program directly??

[Cabhan]

Right. You can use the 'file' command to find out what type of file a file is.

As far as making executable scripts, this is done by setting the executable permission. I have a big explanation on UNIX permissions at:
http://www.linuxforums.org/forum/lin...y-group-2.html
(about halfway down the page)

This allows you to execute the script by giving its absolute path. For instance, if I have a script at /home/user/my_script, I need to type out that entire path. If you want to be able to run the script from anywhere, you need to add it to a location in your $PATH variable. Just run the command:

echo $PATH

to see all the locations that you could put it.

[Juan Pablo]

Linux uses what is called 'magic' , it identifies the files with the first bytes found in the file. For example #! are two 'magic' characters that define an script.

You don't need to name a file in a particular manner to make it run as a script, you write the magic, next the interpreter, make it executable and it should just work.
More info 'man magic'
For example:

#!/usr/bin/perl

will tell the shell that your script needs to be interpreted by the 'perl' binary found on /usr/bin

EDIT: All you are quick