Saint's Log

Simple Batch File Editing with VSCode Copilot Agent

I need to verify that all symbols are available for every executable binary in any given release. I have been modifiying scratchpad/scripts/java/symbols/verify-symbols-initial.bat at 4a9adb7dfd0e67c129320c8a3c6ee38260695b13 · swesonga/scratchpad but realized that I waste a lot of time copy/pasting repo names and tags. I thought I would experiment with Copilot in VSCode to see if it could help me clean up this script. The prompts I used (also at scratchpad/scripts/java/symbols/verify-symbols-prompts.txt at 4a9adb7dfd0e67c129320c8a3c6ee38260695b13 · swesonga/scratchpad) are in the next listing:

delete all lines from ":: jdk21u x64"
replace 2025-07 with a variable called psu
replace aarch64 and x64 with a variable called arch
replace jdk21u with a variable called jdkrepo
replace jdk-21.0.6+7 with a variable called jdktag
replace D:\java\binaries\jdk\%arch%\%psu%\windows-%jdkrepo% with a variable called psudir
output a message showing the psudir after setting it
make the variables user-specified variables
make the variables command line arguments instead

I pasted the screenshots of the result of each prompt into the slideshow below. Notice that I was using Agent mode with Anthropic’s Claude Sonnet 4 model. I was not exactly saving much time in this scenario using the VSCode agent, but I was certainly understanding its capabilities.

I created a duplicate directory with the initial .bat file then used a single prompt with all the lines above. I was pleased that I got the same result!

I was a bit confused the 2nd time I worked through these prompts because the behavior of the agent was different! I didn’t notice that I had somehow switched from Agent mode to Ask mode but I have now learned the difference between these two modes.