What is the syntax for .bat?

Question

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

This basically means the following:

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

?

What setlocalfor?

How does bat identify endif?

Answer 1

to try

setlocal /? 

on the command line

As for the operators if: help ifshould show you everything you need to know. Batch files have only one line ifform expressions

if[state] [operator]
if[state] [operator] else[operator]

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

if[status] (
[Approval]
[Approval]
...
)

if [] (
[]
...
) else (
[]
...
)

end if. if .

, . help set .

Answer 2

http://ss64.com/nt/setlocal.html

Answer 3

: Apache Tomcat

, , . .

• "%OS%" == "Windows_NT"

  Tomcat (catalina.bat) :

  if "%OS%" == "Windows_NT" setlocal
  

  Tomcat 8 ( Tomcat 8 Tomcat 9 - ), :

  setlocal
  

  %OS% Windows_NT Windows. , Microsoft Windows if . setlocal.

  • https://en.wikipedia.org/wiki/Environment_variable#OS (Windows):

    % OS% , . Windows NT, Windows 2000, Windows XP Windows 7 "Windows_NT" . % OS%, DOS- Digital Research-origin, DOS, DOS, REAL/32, DOS Plus, DR DOS, Novell DOS OpenDOS.

  • Windows 8 Windows 10, ( "Windows_NT" ).

  • https://en.wikipedia.org/wiki/Environment_variable#.25OS.25 (DOS):

    , DOS, , [5]. "DOSPLUS" (DOS Plus 1.2 DOS), "CPCDOS 4.1" (DOS Plus 1.2 CP/M), "DRDOS" (DR DOS 3.31-6.0, DR DOS Panther, DR DOS StarTrek, DR- DOS 7.02 [5] -7.05), "EZDOS" (EZ-DOS 3.41), "PALMDOS" "NetWare PalmDOS" (PalmDOS 1.0), "NWDOS" (Novell DOS 7), "NWDOS7" (Novell DOS 7 Beta), "OPENDOS" (Caldera OpenDOS 7.01, Caldera DR-OpenDOS 7.02), "CDOS" ( DOS), "CPCDOS" ( DOS), "CDOS386" ( DOS 386), "DRMDOS" (DR Multiuser DOS), "MDOS" ( DOS CCI), "REAL32" (REAL/32). [2] [6] MS-DOS INTERSVR "DRDOS". [6] . % OS%, Microsoft Windows NT.

• if

  Tomcat ( 8), "%OS%" == "Windows_NT" if "%OS%" == "Windows_NT" setlocal , setlocal . .

  , (, , - . ), ( endif - @setlocal).

  :

  @echo off
  rem testif.bat
  if "1" == "2" echo a
  echo b
  
  if "1" == "1" echo c
  echo d
  

  testif.bat :

  b
  c
  d
  

  , echo a, . , endif echo a ( echo b).

• setlocal

  Tomcat (\ bin\startup.bat) CATALINA_HOME CATALINA_BASE :

  set CATALINA_HOME=%~dp0
  set CATALINA_BASE=%CATALINA_HOME%
  

  setlocal. setlocal, script. " ", script, ( ), , .

  :

  @echo off
  rem 1.bat
  set A=1
  setlocal
  set B=2
  endlocal
  set C=3
  

  script (1.bat) :

  rem - prints 1
  echo %A%
  rem - prints %B%
  echo %B%
  rem - prints 3
  echo %C%
  

  , A C, setlocal endlocal. , echo , ( %A%, %B%, %C%).

  endlocal, , :

  :

  • https://technet.microsoft.com/en-us/library/bb491001.aspx

    setlocal . , setlocal, . Cmd.exe , endlocal .