What is an alternative to a BAT file on Mac? What is the alternate for BAT file (Windows) on Mac? Does different version of OS X have different format of BAT files? I am trying to create a BAT file on Mac which normally changes directory while the file is open.
Being pretty unfamiliar with batch files, I'm not sure of the functionality available, but there are two main scripting methods on OS X which are similar:


AppleScript

AppleScript is a scripting language which lets you control OS X and many applications.

AppleScripts are generally easy to understand and write whilst providing a lot of advanced functionality. Here is an AppleScript which counts the files in the Applications folder:

tell application "Finder"
    if folder "Applications" of startup disk exists then
        return count files in folder "Applications" of startup disk
    else
        return 0
    end if
end tell


For more information about AppleScript, see:


https://developer.apple.com/library/mac/documentation/applescript/Conceptual/AppleScriptX/AppleScriptX.html

Shell script

A shell script is a script for a Unix shell.

The equivalent shell script to the above AppleScript is the following:

if [ -d "/Applications/" ]; then
    ls -1 "/Applications/" | wc -l
fi


As you're probably going to use bash, this is a good guide to get you started:


http://www.tldp.org/LDP/abs/html/