Batch-File: Find string in a file and add text after - batch-file

Question

I generally use the echo method for writing "text" to an HTML-file by using:
echo. >> "C:\Users\Me\Desktop\test.html"
echo ^<div^>TestDIV^</div^> >> "C:\Users\Me\Desktop\test.html"
I've experienced, that echo always writes the additional lines to the end of the target file.
But what if my target file (test.html) already has a structure like:
<div id="wrapperDIV">
<div id="DIVcontent1">DIV 1</div>
<div id="DIVcontent2">DIV 2</div>
</div>
and I want to write the additional lines within this existing structure, for example right after:
<div id="DIVcontent1">DIV 1</div>
I have tried to set up a script for this, but so far I couldn't make it running. (It seems to fail in the for-loop)
set DIVInput=^<div^>TestDIV^</div^>
set inputfile=C:\Users\Me\Desktop\test.html
(for /f usebackq^ delims^=^ eol^= %%a in ("%inputfile%") do (
if "%%~a"=="DIV 1^</div^>" call echo %DIVInput%
echo %%a
))>>"%inputfile%"
pause

Answer 1

Your set DIVInput=... consumes the escaping carets, which is bad in this case, because you need it later to echo the variable correctly. The preferred syntax set "var=value" preserves them (they are safe inside the quoting).
With your if line, you want to check for a substring only, not the whole line (if always compares complete strings and doesn't support wildcards). I used echo fullstring|find "string" to check that. Note that I use quotes (echo "%%~a"') for the same reason as above: proper handling of poison chars like>and<Same reason for not escaping with thefind` command ("save inside quotes")
You redirect to your input file. Redirecting is the first thing for the parser, so the file gets overwritten even before for has a chance to read the file. Use a different file and overwrite your original file when done.
You want to insert a string after a certain trigger line, but your code inserts before that line (well, that's easy to fix).
#echo off
setlocal
set "DIVInput=^<div^>TestDIV^</div^>"
set inputfile=test.html
(for /f usebackq^ delims^=^ eol^= %%a in ("%inputfile%") do (
echo %%a
echo "%%~a" |find "DIV 1</div>" >nul && echo %DIVInput%
))>"%inputfile%.new"
REM move /y "%inputfile%.new" "%inputfile%
Note: I disabled the move command for security reasons. Remove the REM after checking test.html.new looks ok.