2. What is CliWrap?
📦 https://github.com/Tyrrrz/CliWrap - ⭐ 1.3K - 📥 800K
Library for interacting with external command line interfaces. It provides a convenient model for
launching processes, redirecting input and output streams, awaiting completion, handling
cancellation, and more.
● Airtight abstraction over System.Diagnostics.Process
● Fluent configuration interface
● Flexible support for piping
● Fully asynchronous and cancellation-aware API
● Designed with strict immutability in mind
● Provides safety against typical deadlock scenarios
● Tested on Windows, Linux, and macOS
● Targets .NET Standard 2.0+, .NET Core 3.0+, .NET Framework 4.6.1+
● No external dependencies
3. CLI as the Perfect Library Format
Command Line Interface
Inputs Outputs
Command line arguments
Standard input stream
Environment variables
Exit code
Standard output stream
Standard error stream
✔ Any language
✔ Any platform
✔ Consistent protocol
> _
4. Pitfalls of System.Diagnostics.Process
⚠ Poorly designed API
- Process lifetime transitions are not represented by a state machine
- Some configuration properties conflict with each other
- Some process information is unavailable after exiting
- Some user-facing behavior is inconsistent between operating systems
- Async and cancellation support is lacking
⚠ Deadlock and race condition traps
- Buffer overflow in output or error stream may cause a deadlock
- Unterminated input stream may cause a deadlock
- Partially consumed input stream may cause a deadlock
- Reading output or error stream may race with process exiting
- Killing a process may race with its own graceful termination
⚠ Certain usage scenarios are impractical to implement
- Pull-based data streaming
- High-level piping targets
- Process-to-process piping
5. Execute await
CommandResult
Anatomy of CliWrap
Command
Configuration via fluent interface
CommandTask
- Command line arguments
- Environment variables
- Working directory
- Pipe configuration
...
- Process ID - Exit code
- Start time
- Exit time
6. Execute (buffered)
Listen (event stream)
Observe (event stream)
Pipes to in-memory buffers
Pipes to a bounded channel
Pipes to observer delegates
- Standard output
- Standard error
- ...
High-level execution models
BufferedCommandResult
IAsyncEnumerable<CommandEvent>
Command
IObservable<CommandEvent>
8. Thanks for joining!
Find me online:
@Tyrrrz | https://tyrrrz.me
Learn more about CliWrap:
https://github.com/Tyrrrz/CliWrap
See examples used in this webinar:
https://gist.github.com/Tyrrrz/4cf67feea50cfdbbd871f217a10427c4
