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Why I can't CALL "IF" and "FOR" neither in batch nor in the cmd?

Tags:

batch-file

To be honest I don't expect a satisfying answer here.These command cannot be called and that's it (as far as I know the only commands that cannot be used with call). Here are few examples with their output:

C:\Windows\system32>call @if a==a echo called 
',' is not recognized as an internal or external command,
operable program or batch file.

C:\Windows\system32>call (@if a==a echo called)
';' is not recognized as an internal or external command,
operable program or batch file.

C:\Windows\system32>call if a==a echo called
'if' is not recognized as an internal or external command,
operable program or batch file.

C:\Windows\system32>call for  %a in (1) do @echo called
'for' is not recognized as an internal or external command,
operable program or batch file.

C:\Windows\system32>call @for  %a in (1) do @echo called
'+' is not recognized as an internal or external command,
operable program or batch file.

C:\Windows\system32>call (@for  %a in (1) do @echo called)
';' is not recognized as an internal or external command,
operable program or batch file.

I have some suspicious , that IF and FOR are not in fact 'real' commands - they just decide to pass the command prompt control to the line (or brackets block) behind them or not , which confuses the call. Anyway even that , when there are syntax errors in called FOR or IF they are detected:

C:\Windows\system32>call (@if a= echo called)
= was unexpected at this time.

C:\Windows\system32>call (for %a (1) do echo called)
(1 was unexpected at this time.

So at least the parsing is done.

like image 900
npocmaka Avatar asked Oct 18 '13 08:10

npocmaka


2 Answers

You are quite right.

FOR, IF and REM aren't normal internal commands (but for REM exists also a normal internal version).
They use an own special parser (each a different one).

It seems that these commands are translated to a sort of token.
Therefor you got such unexpected error messages (there are much more possible characters), the error/token character depends also of the Windows version (if I remember correct here).
Probably the CALL command sees only the tokenized data from the original command.

Command blocks don't work at all with the call command, also &|<> don't work as expected.

call (a^|a)

Searches for a command/token 2, so if you create a batch file named 2.bat you can start it with call (a^|a).

For further information about CALL
Dostips:CALL me, or better avoid call
Dostips:Limit CMD processing to internal commands, safer and faster?

like image 85
jeb Avatar answered Sep 21 '22 11:09

jeb


After all it is possible to call IF and FOR ..or almost;

    @echo off

rem :: this will produce an error
rem if a equ a

rem :: And this too
rem call if a equ a rem

rem :: But this will not!!!
call if a equ a

rem :: This will not too ((\but in command prompt single % is enough)
call for %%%%a in (.) do

rem :: And this
call if a equ a for %%%%a in (.) do if 1 equ 1  for %%%%a in (.) do if c==c

rem :: And this
call if a equ a for %%%%a in (.) do if 1 equ 1 for %%%%a in (.) do if c==c ( rem rem rem echo something

Despite I see no usage of this.

like image 39
npocmaka Avatar answered Sep 21 '22 11:09

npocmaka