For loop string processing

[remstadt]

Hi! I have a for loop in a *.bat file that looks something like:

Code: [Select]

SET ENVVARLIST=env-vars-list.txt
FOR /F "tokens=1,* delims==" %%A IN (%ENVVARLIST%) DO (
    SETX %%A "%%B"
)
and env-vars-list.txt looks something like:

Code: [Select]

LIB_ROOT=%~dp0%mylib
it basically has a bunch of environment variables with their paths
The For loop doesn't seem to process the %~dp0%
if I put the command in the For loop it works, but since the environment variables all have different paths it's a bit inconvienient.

Does anyone have a fix for this?

[Squashman]

Well for starters your SETX command has no equals sign.  It is removed from your text file in the FOR command because you specified it as a delimiter.

[Squashman]

This should solve your expansion problem

Code: [Select]

@echo off
SET ENVVARLIST=env-vars-list.txt
FOR /F "tokens=1,* delims==" %%A IN (%ENVVARLIST%) DO (
    call SETx %%A="%%B"
)


[Squashman]

But why bother using the equals sign as a delimiter.  Use it to your advantage.

Code: [Select]

@echo off
SET ENVVARLIST=env-vars-list.txt
FOR /F "delims=" %%A IN (%ENVVARLIST%) DO (
    call SETX %%A
)

[remstadt]

Thank you for the reply!
There is a very subtle syntax difference between SET and SETX. Set uses an =, but SETX does not use one. I believe that part of my syntax was correct, but I may be missing the interpretation of your comment...

How do you get the command to parse the %~dp0% when it is read from an external file? when it reads it from the file it doesn't convert it to the current drive and path information... it's treated as a string literal in the environment table.

i.e. I'm hoping that %~dp% gets converted to something like:
C:\Users\MyName\Documents\Visual Studio xxx\Projects\

[remstadt]

testing it with the Call command.... hope that works

[remstadt]

No use of the call command didn't help with the parsing. Any other suggestions?

[Squashman]

No use of the call command didn't help with the parsing. Any other suggestions?

Let me see your code.  It has to work.  The %%A and %%B are expanded first even before the call statement run.  The CALL statement then starts its own environment and expands the %dp0 variable.

Your code should look like this.

Code: [Select]

@echo off
SET ENVVARLIST=env-vars-list.txt
FOR /F "tokens=1,* delims==" %%A IN (%ENVVARLIST%) DO (
    call SETX %%A "%%B"
)
But for testing purposes I am using this.

Code: [Select]

@echo off
SET ENVVARLIST=env-vars-list.txt
FOR /F "tokens=1,* delims==" %%A IN (%ENVVARLIST%) DO (
    call SET %%A=%%B
    set lib_
)

[Squashman]

When I run it with SETX this is the output I get.

Code: [Select]

SUCCESS: Specified value was saved.

[Squashman]

And now when I open up a cmd prompt it is now a static environmental variable.

Code: [Select]

H:\>set lib_
LIB_ROOT=C:\BatchFiles\environ\mylib

[Squashman]

And you should also be aware of this if you are trying to use that new variable in your current batch file.
From the SETX help file

NOTE: 1) SETX writes variables to the master environment in the registry.

      2) On a local system, variables created or modified by this tool
         will be available in future command windows but not in the
         current CMD.exe command window.

[remstadt]

Hah! you were right all along, I just needed to open a new window. Thanks!