CLIWrap is a .NET library designed to simplify the interaction with command line interfaces by providing an easy model for launching processes and managing streams. It offers features like a fluent configuration interface, support for asynchronous operations, and safety against deadlocks. The library is compatible with multiple platforms and aims to overcome the limitations and pitfalls of the System.Diagnostics.Process API.

1. Intro to CliWrap
Leveraging Command Line Tools from .NET Applications
@Tyrrrz | https://tyrrrz.me

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>

7. Coding time!

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