Programmatically send key strokes to a window program in Groovy or bat script

Question

Backstory: I need to programmatically find the differences between two files. I want to use WinMerge to generate a report (Tools -> Generate Report) that I can parse to ge

Answer 1

This is something that I threw together without testing, and I don't have WinMerge so testing isn't really an option.

RunMe.bat

start "" "C:\Path\WinMerge.exe" "file1" "file2"
GenerateDiffFile.vbs

GenerateDiffFile.vbs

Set s = CreateObject("WScript.Shell")

wscript.sleep(1000) ' Sleep for 1 second to allow time for WinMerge to finish loading and merge the files

s.SendKeys("%tr")
wscript.sleep(250) ' Give time for dialog box to appear
s.SendKeys("Diff.html{Enter}")

This is completely untested, but I think it is very close to what you need... You can see that the batch-file runs WinMerge, passing the two files to merge on the command line. Then it launches the VBS script, which pauses long enough to allow the launched WinMerge to be able to accept keyboard input. I used this page from Microsoft to know what keys to send.

I've been sending keys to programs for years. It works very reliably, as long as the program you want to send keys to keeps focus.