startt

feat(startt): hello 'startt' default open tool

startt solves a long-standing Windows poor design/quirk: when you do

• cmd.exe /c start …
• Explorer “Open with” or protocol handler
• PowerShell Start-Process

or anything that calls ShellExecuteEx under the covers (even with SEE_MASK_NOCLOSEPROCESS + WaitForInputIdle), the PID you get back is unusable for apps like Chrome. You can’t reliably find its window handle (HWND) or true process ID for automation, testing, or demos.

Usage:

startt [options] <executable|document|URL> [args...]

Grid and cell assignment options:

• -g ROWSxCOLS[ mMONITOR] or --grid ROWSxCOLS[ mMONITOR]
  Tile each window into a grid on the specified monitor (e.g., -g 2x2m1 for a 2x2 grid on monitor 1, zero-based).
• -fg or --fit-grid
  Resize each window to exactly fit its grid cell before positioning, instead of centering at original size.
• -apc ROWxCOL[ mMONITOR] or --assign-parent-cell ROWxCOL[ mMONITOR]
  Assign the parent window to a specific grid cell and monitor (e.g., -apc 1x1m1). If monitor is omitted, uses the grid's monitor.
• -rpc or --reserve-parent-cell
  Prevents any child window from being assigned to the same grid cell as the parent window (whether default or set by --assign-parent-cell).

Taskbar options:

• -htb or --hide-taskbar
  Attempt to hide the Windows taskbar on the grid's monitor.
• -stb or --show-taskbar
  Attempt to show the Windows taskbar on the grid's monitor.

Other options:

• -f or --follow
  Keep watching for and shaking new child windows.
• -F or --follow-forever
  Keep watching for and shaking new child windows even after the parent has closed.
• --find-oldest
  Use the "oldest" logic instead of most recent.
• -t SECONDS or --timeout SECONDS
  Specify the number of seconds each window should remain open before a quit message is sent to it.
• -hT or --hide-title-bar
  Hide the title bar of the target window.
• -hB or --hide-border
  Hide the border of the target window.
• -T or --flash-topmost
  Briefly set the window as topmost, then restore it.
• -sd MILLISECONDS or --shake-duration MILLISECONDS
  Set the shake animation duration in milliseconds (default: 2000ms).
• -dbg or --debug-chrome
  Rewrite any URL arguments to use the debugchrome:// prefix for debugchrome-cdp-rs support.
• --gui
  Launch the graphical user interface for managing grids, running demos, and launching commands.
• --num-recent COUNT
  Specify the number of recent windows or processes (parents) to track and process (default: 1).

Examples:

startt -f -g2x2m1 -fg -apc 1x1m1 -rpc myapp.exe

This will assign the parent window to cell (1,1) on monitor 1, ensure no child window is placed in that cell, and resize all windows to fit their grid cells.

startt -f -g1x4 -fg -t 10 -hT -T -sd 1500 cargo-e --run-all --run-at-a-time 4

This will shake and grid each window, resize them to fit their grid cells, hide the title bar, briefly flash the window as topmost, and use a 1.5 second shake duration. After 10 seconds, a quit message is sent to each window.

Works with commands that are detached as demonstrated by cmd.exe start:

startt -f -g1x5 cmd /c "start \"parent\" cmd /k echo parent & start \"1\" cmd /k echo 1 & start \"2\" cmd /k echo 2 & start \"3\" cmd /k echo 3 & start \"4\" cmd /k echo 4"

Or use with PowerShell:

startt -f -g1x5 powershell -NoProfile -WindowStyle Normal -Command "1..5 | ForEach-Object { Start-Process powershell -ArgumentList '-NoProfile','-Command','$host.ui.RawUI.WindowTitle = \"Prompt $_ PID=\" + $PID; Write-Host Prompt $_ PID=$PID; Start-Sleep -Seconds 99999' }; Start-Sleep -Seconds 99999"

When grid mode is enabled, each window (parent or child) is moved to the next cell in the grid, wrapping around as needed. With --fit-grid, each window is also resized to fill its cell. This works for both the initial window and any new windows found in follow mode.

cargo-e provides a graphical panic window;

See also:

• A protocol‐handler for launching & controlling Chrome via CDP
  https://crates.io/crates/debugchrome-cdp-rs
• "How to get HWND of window opened by ShellExecuteEx?," StackOverflow
  https://stackoverflow.com/questions/3269390/how-to-get-hwnd-of-window-opened-by-shellexecuteex-hprocess
• PowerBasic forum thread on finding a shelled window handle
  https://forum.powerBasic.com/forum/user-to-user-discussions/powerbasic-for-windows/13933-finding-the-handle-of-a-shelled-window

startt solves the problem of finding the hwnd and process id of a command or url that is launched by cmd.exe /c start, explorer , start-process, or anything that calls shellexecuteex under the covers.

still rough around the edges and not intended for any purpose but demonstration. the lib interface is subject to change - SEMVER rules will be applied.

it shakes the 1st found window; moves windows in grids; kills all child processes on ctrl+c;

tested with chrome, vscode, mpv, msedge, cmd. Your application, mileage, and use case may vary. If you find a problem; take a look at the code, PRs and polite discussion are welcome.

--dave horner
5/25

MIT License

Copyright (c) 2025 David Horner

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