Can I have an IF block in DOS batch file?

Solution 1:

You can indeed place create a block of statements to execute after a conditional. But you have the syntax wrong. The parentheses must be used exactly as shown:

if <statement> (
    do something
) else (
    do something else
)

However, I do not believe that there is any built-in syntax for else-if statements. You will unfortunately need to create nested blocks of if statements to handle that.

Secondly, that %GPMANAGER_FOUND% == true test looks mighty suspicious to me. I don't know what the environment variable is set to or how you're setting it, but I very much doubt that the code you've shown will produce the result you're looking for.

The following sample code works fine for me:

@echo off

if ERRORLEVEL == 0 (
    echo GP Manager is up
    goto Continue7
)
echo GP Manager is down
:Continue7

Please note a few specific details about my sample code:

• The space added between the end of the conditional statement, and the opening parenthesis.
• I am setting @echo off to keep from seeing all of the statements printed to the console as they execute, and instead just see the output of those that specifically begin with echo.
• I'm using the built-in ERRORLEVEL variable just as a test. Read more here

Solution 2:

Logically, Cody's answer should work. However I don't think the command prompt handles a code block logically. For the life of me I can't get that to work properly with any more than a single command within the block. In my case, extensive testing revealed that all of the commands within the block are being cached, and executed simultaneously at the end of the block. This of course doesn't yield the expected results. Here is an oversimplified example:

if %ERRORLEVEL%==0 (
set var1=blue
set var2=cheese
set var3=%var1%_%var2%
)

This should provide var3 with the following value:

blue_cheese

but instead yields:

_

because all 3 commands are cached and executed simultaneously upon exiting the code block.

I was able to overcome this problem by re-writing the if block to only execute one command - goto - and adding a few labels. Its clunky, and I don't much like it, but at least it works.

if %ERRORLEVEL%==0 goto :error0
goto :endif

:error0
set var1=blue
set var2=cheese
set var3=%var1%_%var2%

:endif

Solution 3:

Instead of this goto mess, try using the ampersand & or double ampersand && (conditional to errorlevel 0) as command separators.

I fixed a script snippet with this trick, to summarize, I have three batch files, one which calls the other two after having found which letters the external backup drives have been assigned. I leave the first file on the primary external drive so the calls to its backup routine worked fine, but the calls to the second one required an active drive change. The code below shows how I fixed it:

for %%b in (d e f g h i j k l m n o p q r s t u v w x y z) DO (
if exist "%%b:\Backup.cmd" %%b: & CALL "%%b:\Backup.cmd"
)