SilentRunner.exe

Run Windows CLI commands silently and capture exit code, stdout and stderr.

SilentRunner is a lightweight Windows tool that runs commands silently (no console window) via cmd.exe and captures exit code, stdout and stderr.
Useful for automation, Task Scheduler jobs, scripting, and tools that require silent execution with output retrieval. AI-assisted project — see Acknowledgements for more info.

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Features

✔ Runs commands via cmd.exe (child process) — supports pipes, &&, |, builtins (echo, chcp, ...)
✔ Silent execution (no flashing console window)
✔ Captures exit code, stdout and stderr without deadlocks
✔ Optional timeout with best-effort process tree kill
✔ Streams are passed as raw bytes (no CRLF/encoding conversion)
✔ Single .exe — no dependencies

More detailed internal behavior, CMD execution model, quoting rules, and limitations are extensively documented
inside src/SilentRunner.cpp in the header section.

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Usage

SilentRunner supports two execution modes:

• Script/Executable path mode: <script-or-exe> [args...]
• Raw command mode: -c "<raw-cmd>"

SilentRunner.exe [options] <script-or-exe> [args...]
SilentRunner.exe [options] -c "<raw-cmd>"

CLI Options

Option	Description
--timeout-ms <N>	Kill process tree after N ms → exit code 124
--print-cmdline	Print PID + CMD command to stderr (debug)
--utf8	Prepends chcp 65001>nul & ... inside child
-c "<cmd>"	Raw inline command instead of script mode

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Examples

Run inline command:

SilentRunner.exe -c "echo Hello & ver"

Run program with arguments:

SilentRunner.exe "C:\Tools\app.exe" --mode fast --silent

Run .cmd script with parameters:

SilentRunner.exe backup.cmd D:\ 20

backup.cmd example:

@echo off
REM disable command echo for cleaner output
set "DRIVE=%~1"
set "DAYS=%~2"
echo Backing up %DRIVE% (keeping %DAYS% days)

UTF-8 mode:

SilentRunner.exe --utf8 -c "echo こんにちは"

Timeout example:

SilentRunner.exe --timeout-ms 5000 "medium_running_task.cmd"

About stdin

SilentRunner binds stdin to NUL, so external input pipes do not work:

✗ echo yes | SilentRunner.exe -c "somecommand"    # won't work
✓ echo yes | somecommand                          # works only inside .cmd script

Behavior Notes

• Execution is synchronous — output is delivered only after the child process exits
• Output is fully buffered in RAM → not ideal for GB-scale logs
• stdout/stderr order is not preserved — both streams are drained concurrently and replayed sequentially after the process exits
• Working directory inherits the parent’s — use absolute paths, or pushd/popd inside .cmd if needed
• -c is convenient for short one-liners, but CMD quoting rules can get tricky
• For complex commands involving quotes, pipes or variables, using a .cmd script is usually safer
• For long-running or fire-and-forget tasks, use nircmd exec hide instead — https://nircmd.nirsoft.net/exec.html

Full technical notes including implementation details, quoting behavior, caveats and design reasoning
are documented at the top of src/SilentRunner.cpp.

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Build

Prebuilt binary is included in bin/.

Manual compilation is optional — full build steps (toolchain, flags, notes) are documented inside the header of src/SilentRunner.cpp under Build section.

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Acknowledgements

Developed in C++ with a focus on a minimal, self-contained Windows binary without external dependencies, using direct WinAPI process handling — ideal for this type of tool. The code and documentation were created with assistance from ChatGPT (v5.2) and iteratively reviewed, refined, and extensively tested during development to validate reliability and performance. Contributions, bug reports, and security notes are welcome.

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License

Released under the MIT License — see LICENSE for details.

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