Script to convert fixed width flat file to csv - batch-file

Question

I want to make a generic script which will convert a fixed width flat file into csv. Below is my approach:
`echo off
setlocal EnableDelayedExpansion
echo a,b,c>final.txt
for /f "tokens=1 delims=;" %%i in (source.txt) do (
set x=%%i
for /f "tokens=1,2 delims=," %%a in (config.txt) do (
call SET VAR=!x:~%%a,%%b!
for %%p in (!VAR!) do (echo/|set /p ="%%p,"
) >>final.txt
)
)
`
Config file which I am using contains the parameters for substring which states from where to do the substring and how many characters.
Config file contains:
0,9
9,3
12,11
23,7
30,1
31,1
32,5
37,9
46,9
55,3
58,9
67,9
76,9
85,9
94,1
Source file contains the actual fixed with source.
Now with my code I am getting the result but for the fields which has no value/empty in the source is not reflecting in the final output.
Example:
Source:
1234<space>678 [col1=678,col2=space,col3=678]
Output (Current):
1234,678
Output(Expected):
1234,,678
Please help

Answer 1

Your for %%p in (!VAR!) do (…) loop executes defined (…) command for all strings found in !VAR! delimited with white space(s). So if !VAR! results to all white spaces, then consequential for %%p in ( ) do (…) loop executes nothing. Next code snippet could help:
echo off
setlocal EnableDelayedExpansion
echo a,b,c>final.txt
rem replace the €€€ string with any unused one
set "fooString=€€€"
for /f "tokens=1 delims=;" %%i in (source.txt) do (
set "x=%%i"
for /f "tokens=1,2 delims=," %%a in (config.txt) do (
call SET "VARraw=!x:~%%a,%%b!%fooString%"
rem replaced with respect to the OP's comment: for %%p in (!VARraw!) do (
for /F "tokens=*" %%p in ("!VARraw!") do (
set "rav=%%p"
set "var=!rav:%fooString%=!"
echo/|set /p "=!var!,"
) >>final.txt
)
)
Edit: note that for /F "tokens=*" %%p in ("!VARraw!") do ( would remove leading spaces from the !VARraw! string.