Question

if "%OS%"=="Windows_NT" @setlocal
...
if "%OS%"=="Windows_NT" @endlocal

Does the above basically mean this:

if(OS == 'Windows_NT'):
...
endif

?

What’s setlocal for ?

How do bat identify the endif?

Answer 1

try

setlocal /? 

on command prompt

As for if statements: help if should show you everything you need to know. Batch files have only single line if statements of the forms

if    [condition]    [statement]
if    [condition]    [statement]    else    [statement]

However, [statement] can be a block, delimited by parentheses:

if    [condition]    (
    [statement]
    [statement]
    …
)

if    [condition]    (
    [statement]
    …
)    else    (
    [statement]
    …
)

There is no explicit end if keyword. The end of the if statement is marked by the end of the line or by the end of the parenthesized block.

Also keep in mind that you need to be careful with setting and subsequently using environment variables in a single block. Read up in help set on delayed expansion for the pitfalls there.