Batch: Don't parse comment of key-value - parsing

Question

I am using the following code to parse an config.ini-file:
#setlocal enableextensions enabledelayedexpansion
#echo off
set file=%~1
set area=[%~2]
set key=%~3
set currarea=
for /f "usebackq delims=" %%a in ("!file!") do (
set ln=%%a
if "x!ln:~0,1!"=="x[" (
set currarea=!ln!
) else (
for /f "tokens=1,2 delims==" %%b in ("!ln!") do (
set currkey=%%b
set currval=%%c
if "x!area!"=="x!currarea!" if "x!key!"=="x!currkey!" (
echo !currval!
)
)
)
)
endlocal
It works fine as long as there are no comments in the same line as they keys and values.
For example:
[BACKUP]
HOST=128.110.111.11 ;Comment is included in !currval!
PORT=5901
USER=user1
Unfortunately I can't find a way to exclude everything after the last character of the string "128.110.111.11"..
Any help is appreciated. Thanks!

Answer 1

The best batch has to offer towards achieving the goal is a combination of for loops to process the string. There is no innate command that can achieve this in a single step.
In a way though, you can make a command to complete the necessary set of commands by a assigning them to a variable as a macro
For example, in the below script the macro completes the necessary steps for this goal by:
Delimitng the Variables content using ;
Iterating over the length of the string from end to start - The example assumes a maximum string length of 250 characters; an arbitrary number for the point of the example.
Remove only trailing spaces using If condition logic and substring modification
Stop further modification of the variables content by using a true/false switch to flag that the last digit of the string contains a non-space character
Note : Substring modification is used at the point of the the macros expansion to supply the name of the variable to be processed.
#Echo off & Setlocal enableDelayedexpansion
Set "RemTrail=Set "end=0"&(For /F "Tokens=1 Delims=;" %%G in ("^^!$v^^!")Do Set "$V=%%G")&For /L %%i in (250,-1,0)Do (if "^^!$V:~%%i,1^^!"==" " (If not "^^!End^^!"=="1" Set "$V=^^!$V:~0,%%i^^!")Else (If not "^^!$V:~%%i,1^^!"=="" Set "End=1"))"
rem // usage example
Set "string=trail of spaces ; comment string "
Set "string2=uncommented string with trailing spaces and poison chars < & " " | * > "
Echo/[!string!]
Echo/[!string2!]
%RemTrail:$V=String%
%RemTrail:$V=String2%
Echo/[!string!]
Echo/[!string2!]
A slighty modified version that Allows the Delimiter to be modified at expansion, at the expense of returning the modified result in a fixed return variable ($V) instead of the original variable name:
#Echo off & Setlocal enableDelayedexpansion
Set "RemTrail=For %%n in (1 2)Do if %%n==2 (Set "end=0"&(For /F "Tokens=1 Delims=DLM" %%G in ("^^!$V^^!")Do Set "$V=%%~G")&For /L %%i in (250,-1,0)Do (if "^^!$V:~%%i,1^^!"==" " (If not "^^!End^^!"=="1" Set "$V=^^!$V:~0,%%i^^!")Else (If not "^^!$V:~%%i,1^^!"=="" Set "End=1")))Else Set $V="
rem // usage example
Set "string=trail of spaces ; comment string "
Set "string2=uncommented string with trailing spaces + poison chars < & | * " " > "
Echo/[!string!]
Echo/[!string2!]
%RemTrail:DLM=;%"!string!"
Echo/[!$V!]
%RemTrail:DLM=;%"!string2!"
Echo/[!$V!]
%RemTrail:DLM=+%"!string2!"
Echo/+ Delim example&Echo/[!$V!]

Answer 2

Solution 1:
for /f "usebackq delims=;" %%a in ("!file!") do (
Including the semicolon as a delimiter ensures only that part of the line up to, but not including the semicolon is assigned to token 1 which is assigned by default to the metavariable %%a
Disadvantage : the spaces between the end of the string and the semicolon are retained in %%a and hence currval and will be echoed.
Solution 2 :
for /f "tokens=1,2 delims== " %%b in ("!ln!") do (
Inclusion of the space as an extra delimiter will assign the value between the first delimiter found (=) and the second ([space]) to %%c.
Disadvantage : The value displayed as %%c will be truncated at the space
Solution 3:
Use solution 1 and then change
set currval=%%c
to
CALL :setcurrval %%c
AND then endlocal becomes
endlocal
goto :eof
:setcurrval
SET "currval=%*"
goto :eof
which terminates the local environment and exits the batch.
CALLing the internal subroutine :setcurrval assigns the value of the remainder of the line to currval, except for the terminal spaces, hence producing %%c minus any terminal spaces.
Note that the colons are significant.