Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
533 views
in Technique[技术] by (71.8m points)

if statement - Can I have an IF block in DOS batch file?

In a DOS batch file we can only have 1 line if statement body? I think I found somewhere that I could use () for an if block just like the {} used in C-like programming languages, but it is not executing the statements when I try this. No error message either. This my code:

if %GPMANAGER_FOUND%==true(echo GP Manager is up
goto Continue7
)
echo GP Manager is down
:Continue7

Strangely neither "GP Manager is up" nor "GP Manager is down" gets printed when I run the batch file.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

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

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...