CommandLine.NetCore

CommandLine.NetCore library provides support to handle command line arguments (parse, validate, command pattern) for .Net Core console applications with ANSI VT support (cursor,colors,screen size) for multi-plateform (windows, linux, osx, arm) console applications using C# and .NET Core 6

This project is licensed under the terms of the MIT license: LICENSE.md

Index

Features
How to
Versions history

Features

The library provides functionalities needed to build console applications running in a terminal (WSL/WSL2, cmd.exe, ConEmu, bash, ...) with text interface. That includes:

parsing command line arguments
command pattern helps implementing commands binded to methods from command line in a simple and regular way
multi-language commands help configuration files
automatic help command
can compile a .exe for a a single command command, showing only the help for a specific command, or for several commands, showing a help for all commands as a shell would do
compatible with AnsiVtConsole.NetCore :
- a text printer engine that supports print directives (markup) allowing to manage console functionalities from text itself, as html would do but with a simplest syntax (that can be configured). That makes possible colored outputs, cursor control, text scrolling and also dynamic C# execution (scripting), based on System.Console and ANSI VT100 / VT52 (VT100 type Fp or 3Fp, Fs, CSI, SGR)
- A Ansi Parser that can identify/remove escape sequences in a text
- The console output can be controlled by:
  - tokens in a string (print directives)
  - as string shortcuts (dynamic ansi vt strings)
  - throught API methods

Howto

1. Running the command line

download the nuget from command line or add it from Visual Studio

dotnet add package CommandLine.NetCore

Notice

When installing the package, the following files are copied into your project:

Config/appSettings.core.json

the file Config/appSettings.core.json is mandatory since it contains the CommandLine.NetCore parser root configuration

link to the library in your console application main class (example: Program.cs):

using CommandLine.NetCore.Services.CmdLine;

from your main method of your app or using top level statements, transfer control to the library CommandLine.NetCore :

Program.cs

namespace MyConsoleApp;

/// <summary>
/// command line input
/// <para>commandName ( option (optionValue)* | parameter )* globalOption*</para>
/// </summary>
/// <param name="args">arguments</param>
/// <returns>status code</returns>
public static int Main(string[] args)
    => new CommandLineInterfaceBuilder()
        .Build(args)
        .Run();

or using a top level statement:

new CommandLineInterfaceBuilder()
    .Build(args)
    .Run();

That leads to the loading of any command line components like global arguments, commands and help settings from both the library core and your own console app and parsing of the declared syntaxes and eventualy execution of the method corresponding to the matching syntax.

2. Testing the integrated help command:

Any console application built with the library ComandLine.NetCore implements by default a command named help that dump any available help about commands that are implemented in the software that uses the library and in the library itself.

As an example, you can build the example application console, provided in the project CommandLine.NetCore.Example, Just execute in your favorite shell this command (available in the folder bin/Release/net6.0):

./CommandLine.NetCore.Example.exe help

To get the help for a particular command, the syntax is help {commandName}. In this example you get help about the command help:

./CommandLine.NetCore.Example.exe help help

3. Configuring the library and a console application built with it

The library settings provides the description of the application and of the commands, and also the translation of texts. You should override these settings according to your needs.

Every settings are pushed throught IHostBuilder.ConfigureAppConfiguration. Settings are looked up by this way, in the specified order:

provided by the library CommandLine.NetCore:

appSettings.core.json : this file contains the settings needed by the core functionalities of the library: decription of the library, texts and description of the integrated command, in the default language (en-us)
appSettings.core.{culture}.json : same as above, any of these files provides translations for the culture specified by the tag {culture} according to available cultures specified in Microsoft.. The settings file that matches the current platform culture is loaded if it exists.

provided by your application;

appSettings.json : dscription of the commands provided by your application, the texts, and any settings in the default language (en-us)
appSettings.{culture}.json : same as above for the translations of the culture specified by the tag {culture}

The settings must conform with the following conventions:

Informations about application

"App": {
    "Title": "CommandLine.NetCore",
    "ReleaseDate": "10/12/2022"
  }

Texts

"Texts": {
    "{TextId}": "Text"
  }

Description of the commands

"Commands": {
    "{CommandName}": {
        "Description": "short description of the command",
        "Syntax": {
            "{Syntax 1}" : "Description of the functionality provided by the syntax 1",
            ...
            "{Syntax n}" : "Description of the functionality provided by the syntax n",
        },
        "Options": {
            "{Option 1}" : "Description of the command option 1",
            ...
            "{Option n}" : "Description of the command option n",
        }
    }
  }

example of the command help :

"Commands": {
    "help": {
      "Description": "output a of list commands and global arguments or output help about a command",
      "Syntax": {
        "": "list all commands",
        "commandName": "help about the command with name commandName"
      },
      "Options": {
        "-v": "enable verbose: add details to normal output",
        "--info" : "output additional informations about the command line context"
      }
    }
  },

These settings are describing the following syntaxes for the command help:

; help for a command
help {commandName} [-v] [--info]
; global help (all commands)
help [-v] [--info]

Command options are optionals and are available for any syntax of the command (here -v and --info). They can appears from the position they are declared in the command syntax

Description of the global arguments

"GlobalOptions": {
    "{ArgumentName}": {
        "{Syntax}" : "Description of the functionality provided by the argument syntax"
    }
  }

Global arguments are optional and availables for any command. They must appear from the end of the command arguments

example of the global argument s :

"GlobalOptions": {
    "s": {
        "-s" : "turn off any output (silent mode)"
    }
  }

by convention (POSIX), single letter arguments are prefixed by -, whereas arguments with several letters are prefixed by --

4. Implementing a command

4.1. Implementing a command with a class

A command specification and implementation is defined in a class that inherits from CommandLine.NetCore.Services.CmdLine.Commands.Command.

the name of the command is kebab case from the name of the class (in this case GetInfo declares the get-info command)
the command class msut have a constructor with parameter Dependencies. These classes are instantiated by the dependency injector, thus any registered dependency can be added as a constructor parameter
the command class must implements the method:
```
CommandResult Execute(ArgSet args)
```
the method Execute declares the syntaxes of the command and the related implementations
the method For declares a command syntax:
```
For(params Arg[] syntax)
```

the list of arguments are specifing the command syntax
- an Arg is either an option or a parameter. Their grammar is defined as this:
  - Option ::= [-|--]{optionName}[value0..valuen]
    - options can be expected or optionnal
    - options can have from 0 to n values
    - can have from 0 to n values of a type T, where T can be any scalar type, a collection of scalar types (with , as separator) or an Enum
    - an option can be defined with values, values are always expected
    - Opt("x") builds the option x with no expected value: -x
    - by convention (posix), if the length of the name of the option is greater than 1, the prefix becomes: --. For instance, Opt("xy") defines the syntax: --xy
    - Opt("x",true) builds the option x wich is optional in the syntax
    - Opt<T>("value") builds the option value having one expected value that must be convertible to type T. For instance, Opt<int>("value") defines an option that expect an int, like in syntax: --value 123
    - Flag is a construct of an Opt without value
  - Parameter ::= parameterValue?
    - parameters have exactly one value
    - parameters are always expected
    - have a value of a type T, where T can be any scalar type, a collection of scalar types (with , as separator) or an Enum
    - if a parameter if defined with a value, it is an expected word in the syntax
    - if a parameter is defined without a value, a value is expected in the syntax
    - Param() builds a parameter that expect a value of type string like in syntax: iamastring
    - Param<T>() builds a parameter that expect a value that must be convertible to type T. For instance, Param<int>() builds a parameter that expect a value of type int, like in syntax: 123
    - Param("color") builds a parameter that is expected and being the syntax: color

the method Do chained to a For indicates the method that must be executed if the syntax match the command line args:

the most common way to define the operation method si the lambda expression, since it allows to use a standard method with concrete typed parameters (not Opt,Param,.. but the values types inside it) :

// takes a method in a lambda unary call expression: () => methodName, takes a called method with no parameter, takes a called method with a default command result (code ok, result null).
// Allows to map command arguments to method parameters and operation context
Do(LambdaExpression expression)

others operation methods prototypes that are accepted:

// with no parameter and void result delegate
Do(Action @delegate)

// with no parameter and void result delegate
Do(Func<OperationResult> @delegate)

// with parameter operation context and void delegate
Do(Action<CommandContext> @delegate)

// with parameter operation context and OperationResult result delegate
Do(Func<CommandContext, OperationResult> @delegate)

the lambda expression in the method style Do(LambdaExpression expression) can have one of these profiles:
- the most practical is the use of concrete values types (not Opt,Param,.. but the values types inside it):

// arguments mapping to concrete types
// also accepts an CommandContext parameter placed anywhere
// also accepts explicit mapping of arguments, with positional references in syntax, and no result
// avoid repeating the command arguments declarations (Param, Opt)
void MyOperation( string arg0, bool arg1 , ..)

  - others lambda expressions prototypes that are accepted:

// no parameter and no result
void MyOperation()

// explicit mapping of arguments, with positional references in syntax, and no result
void MyOperation([MapArg(1) Param<string> arg0,[MapArg(5)] Opt<bool> arg1)

// implicit mapping of arguments and no result
// expected arguments (arguments having expected valie(s)) are mapped according to their declaring order
void MyOperation(Param<string> arg0,Opt<bool> arg1)

// can also have an auto-mapped parameter to the operation context:
// a parameter of type CommandContext can be placed anywhere in the parameters list
void MyOperation(...,CommandContext context,..)

methods For can be chained
the method Options can be chained to a For. This method allows to declare the command global options (avalaible for any syntax of the command) :
```
Options(params IOpt[] options)
```
the method With launch the command executing process. First command line parsing, then syntax matching, then operation dispatch:
```
With(ArgSet args)
```

Arguments to concrete types mapping of `Do(LambdaExpression expression)` expression parameters:

Flags

argument constructor	possible corresponding type(s)
`Flag("argName")`	`bool`
`Flag("argName",isOptional: true)`	`bool`

Options

argument constructor	possible corresponding type(s)
`Opt("argName")` `Opt("argName",valueCount:0)`	as it is expected to exactly match the syntax argName (expected values count = 0), this arg must not be mapped
`Opt("argName",isOptional: true)` `Opt("argName",isOptional: true,valueCount:0)`	`bool` (because expected values count = 0, acts as `Flag` in that case)

`Opt("argName",valueCount:1)`	`string`
`Opt("argName",isOptional: true,valueCount:1)`	`string?` or null

`Opt("argName",valueCount:2..n)`	`List<string>`
`Opt("argName",isOptional: true,valueCount:2..n)`	`List<string>?` or null

`Opt<T>("argName",valueCount:0)`	as it is expected to exactly match the syntax argName (expected values count = 0), this arg must not be mapped
`Opt<T>("argName",isOptional: true,valueCount:0)`	`bool` (because expected values count = 0, acts as `Flag` in that case)

`Opt<T>("argName")` `Opt<T>("argName",valueCount:1)`	`T`
`Opt<T>("argName",isOptional: true)` `Opt<T>("argName",isOptional: true,valueCount:1)`	`T?` or default
`Opt<T>("argName",valueCount:2..n)`	`List<T>`
`Opt<T>("argName",isOptional: true,valueCount:2..n)`	`List<T>?` or null

Parameters

argument constructor	possible corresponding type(s)
`Param()`	`string`
`Param_T()`	`T`
`Param("keyWord")`	as it is expected to exactly match the syntax keyWord, this arg must not be mapped

Exemple of the command `help` defined in `CommandLine.NetCore.Commands.CmdLine`:

// command syntax: help [commandName] [-v] [--info]
internal sealed class Help : Command
{
    protected override CommandResult Execute(ArgSet args) =>

        // syntax: help
        For()
            .Do(() => DumpHelpForAllCommands)

        // syntax: help {commandName}
        .For(Param())
            .Do(() => DumpCommandHelp)

        // any syntax accepts -v and/or --info
        .Options(Opt("v"), Opt("info"))

        // parse and run
        .With(args);

    
    private void DumpCommandHelp(string commandName, bool verbose, bool info)
    {
        // ...
    }

    private void DumpHelpForAllCommands(bool verbose, bool info)
    {
        // ...
    }
}

Exemple of the command `get-info` defined in `CommandLine.NetCore.Example.Commands.GetInfo`:

// syntax: get-info (env -l) | (env {varName}) | console | system | --all
internal sealed class GetInfo : Command
{
    protected override CommandResult Execute(ArgSet args) =>

        // syntax: get-info env -l
        For(
            Param("env"),
            Opt("l")
            )
                .Do(DumpAllVars)

        // syntax: get-info env {varName}
        .For(
            Param("env"),
            Param())
                .Do(() => DumpEnvVar)

        // syntax: get-info console
        .For(
            Param("console"))
                .Do(DumpConsole)

        // syntax: get-info system
        .For(
            Param("system"))
                .Do(DumpSystem)

        // syntax: get-info --all
        .For(
            Opt("all"))
                .Do(DumpAll)

        // parse and run
        .With(args);

    private void DumpEnvVar(string envVarName)
    {
        // ...
    }
}

4.2. Implementing a classless command with a lambda expression

You can dynamically declares and specify a command directly with CommandLineInterfaceBuilder fluent methods:

AddCommand adds a new dynamic command named commandName that is specified by the delegate type DynamicCommandSpecificationDelegate

CommandInterfaceBuilder AddCommand( commandName , DynamicCommandSpecificationDelegate )

the delegate DynamicCommandSpecificationDelegate provides a CommandBuilder and a DynamicCommandContext that provides methods for specify and implements the dynamic command
```
(builder, ctx) => ...
```

The CommandBuilder exposes the following methods:

the For method is the way to specify a command arguments, help and body (it is the same than in the abstract class Command)

SyntaxExecutionDispatchMapItem For(params Arg[] syntax)

methods for building arguments: Opt, Flag, Param, OptSet
Help for dynamically (outside of appsettings) declares the command syntax help:

CommandBuilder Help(string text, string? culture = null)

Tag associates one or several tags to the command specification
Package specify a package the command belongs to

The SyntaxExecutionDispatchMapItem has now specific methods for building dynamic commands:

new Do methods with generic types that takes an Action delegate as the command implementation

SyntaxMatcherDispatcher Do<T1>(Action<T1> action)
SyntaxMatcherDispatcher Do<T1, T2>(Action<T1, T2> action)
...
SyntaxMatcherDispatcher Do<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(Action<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> action)

new Do for commands with returns (pending impl.)

SyntaxMatcherDispatcher Do(Func<CommandContext, CommandLineResult> @delegate)

Help for dynamically (outside of appsettings) declares the command syntax help:

SyntaxExecutionDispatchMapItem Help(
        string argsSyntax,
        string description,
        string? culture = null)

Example of the command `add` defined in `CommandLine.NetCore.Example.Program`:

// the command line interface builder still loads commands defined in classes
new CommandLineInterfaceBuilder()

    // we add a command dynamically specified
    .AddCommand("add", (builder, ctx) => builder

        .Help("add operator")
        .Tag(Tags.Math, Tags.Text)

        .For(builder.Param<int>(), builder.Param<int>(), builder.Param<int>())
            .Help("x y z", "returns x+y+z")
            .Do((int x, int y, int z) =>
            {
                ctx.Console.Out.WriteLine($"{x}+{y}+{z}={x + y + z}");
            })

        .For(builder.Param<int>(), builder.Param<int>())
            .Help("x y", "returns x+y")
            .Do((int x, int y) =>
            {
                ctx.Console.Out.WriteLine($"{x}+{y}={x + y}");
            })

        // ...

5. Setup an unique command console app (without command argument)

0 You can prepare a console application that run immediately a specific command at launch and that doesn't requires a command name argument, by activating this option in the main of your app or using top level statements as shown below:

Program.cs

using CommandLine.NetCore.Services.CmdLine;

new CommandLineInterfaceBuilder()

    // add this for single command mode (here: only get-info, no global help)
    // case of a class command
    .ForCommand<GetInfo>()
    // case of a dynamic command (here: only add, no global help)
    //.ForCommand("add")

    // add this to avoid global help of the command line parser
    .DisableGlobalHelp()
    
    .Build(args)
    .Run();

This example will produce an executable that do not accept a command name parameter neither the help global command. If the program is compiled as MyConsoleApp.exe the following command lines are accepted:

get help about the get-info command:

MyConsoleApp.exe -h

┌──────────────────────────────────────────────────┐
│ CommandLine.NetCore.Example (1.0.9.0 05/08/2023) │
└──────────────────────────────────────────────────┘

sample command that output informations about system and console

-h : help about this command
--all : output all infos
console : dump infos about console
env -l : list of environment variables names and values
env varName : dump environment variable value with name varName
system : dump infos about system

run the get-info command:

MyConsoleApp.exe system

system informations:

Operanting System = Microsoft Windows NT 10.0.22621.0
ProcArch = AMD64
Processor Model = Intel64 Family 6 Model 165 Stepping 2, GenuineIntel
Processor Level = 6
System Directory = C:\WINDOWS\system32
Processor Count = 12
User Domain Name = LAPTOP-R3538U70
User Name = franc
Version = 6.0.20
C:\ =
C:\ Volume Label = Windows
C:\ Drive Type = Fixed
C:\ Drive Format = NTFS
C:\ Total Size = 511280410624
C:\ Available FreeSpace = 98612314112

6. Command classes attributes

[IgnoreCommand] : if placed above a command class declaration, the command will be ignored by the command classes loader
[Tag(tag1,..,tagn)] : when placed above a command class declaration, this associates one or several tags to the command specification
[Package(name)] : when placed above a command class declaration, specify that the command belongs to a named package. When not specified, command package is global

7. Debug and troobleshoot

Integrated options

Integrated command line parser options may help the command developer to fix issues:

parser traces

--parser-logging logLevel enable display of parser syntaxes analysis detailed informations. Possibles values from Microsoft.Extensions.Logging.LogLevel. If Trace or Debug the parser add detailed informations about the parsed syntaxes

CommandLine.NetCore.Example.exe help --parser-logging Debug

HelpAboutCommandSyntax: 0:Opt<String>-h 1:Opt?<String>-v 2:Opt?<String>--info 3:Opt?<String>-v 4:Opt?<String>--info : match=False
DumpHelpForAllCommands: 0:Opt?<String>-v 1:Opt?<String>--info 2:Opt?<String>-v 3:Opt?<String>--info : match=True
DumpCommandHelp: 0:Param<String>? 1:Opt?<String>-v 2:Opt?<String>--info 3:Opt?<String>-v 4:Opt?<String>--info : match=False

parser setup

--exclude-ambiguous-syntax exclude any ambiguous syntax when parsing command line arguments. By default, the first matching syntax is selected in the command line arguments parser. If this option is set syntaxes of a command can't be ambiguous

Versions history

1.0.28,1.0.29,1.0.30 - 04/11/2024

AppHostBuilder call ConfigureDelegate prior to configure

1.0.27 - 02/16/2024

add ignore class command method by type and by name
add echo option --no-cr
Flag default is optional set to true

1.0.24,1.0.25,1.0.26 - 02/16/2024

add french translation appSettings.core.fr-FR.json
fix nuget content files
update lib ansi

1.0.22,1.0.23 - 02/14/2024

fix version number of app in help title box

1.0.21 - 02/12/2024

add support for environment variables. switch config by environment from DOTNET_ENVIRONMENT
fix AppHostConfiguration service registering

1.0.20 - 02/12/2024

add support for settings with Environment name

1.0.19 - 02/01/2024

fix command get-info --all syntax was not recognized

1.0.18 - 02/01/2024

fix bug command without tag not displayed in help command list

1.0.12,1.0.13,1.0.14,1.0.15,1.0.16,1.0.17 - 02/01/2024

set Opt default value count to 1 (distinguish from Flag)
fix nullable parameter identification in case of classes (string, ..)
add command class attribute Tag,Namespace,Package + dynamic commands specification method Tag,Namespace,Package
fix dynamic commands set injection scope
/!\ breaking change: removed class CommandLineResult, use CommandResult instead
add tests project
improve help display
fix nuget
fix help -t behavior
doc update

1.0.11 - 10/01/2024 (since 09/12/2023)

add possiblity to declare and implement a command using uniquely a fluent syntax and no class (dynamic commands)
add support for actions with typed parameters in SyntaxExecutionDispatchMapItem
fix value was not nullable in Param_T when T is not a class, for instance, Param{int} always had value 0 (=default(T))
add ignore command attribute
more properties in CommandContext
add initialization errors collect and display
renamings (eg. OperationResult)
update as consts of null syntax name and null value text
add support of dynamic and localized configuration
fix help support of dynamic polymorphic commands syntaxes
doc update

1.0.10 - 08/11/2023

add support of mapping to array parameters when possible (instead of List) in command lambda operations
add global option --disable-global-help
doc update

1.0.9 - 08/06/2023

add support of mapping for parameters having arguments concrete values types in command lambda operation (not Opt,Param,.. but the values types inside it)
fix bug GetValue when not setted option
migrate help,test and get-info commands operations methods with concrete type mapping
improve mapping errors feedback
add SyntaxMatcherDispatcherException and subclasses

1.0.8 - 01/14/2023

add single command mode allowing to build an executable for only one command and eventually without the global help
change editor config and code cleanup
packages update

1.0.7 - 01/13/2023

add global option --no-color that turn off ansi/vt outputs
fix auto syntax -h was not passing global arguments
new RunCommand in current host
improve help output
embed symbols and sources

1.0.6 - 01/11/2023

fix MAJOR bug in command options parsing. Were not recongnized correctly
AppHostBuilder moved to namespace CommandLine.NetCore.Services.AppHost
fix auto command -h (Command.RunCommand) didn't call back configure and build delegates
fix support of -v and --info in -h auto syntax
doc update

1.0.5 - 01/05/2023

fix nupkg: adding the package to a project now deploy files Config/appSettings.core.json, LICENSE.md, README.md, assets/ascii-icon.png in your project. These files are configured as 'Content' and are deployed in the bin folder. You can remove any of these files EXCEPT Config/appSettings.core.json wich is mandatory since it contains the CommandLine.NetCore parser root configuration
fix doc

1.0.4 - 01/04/2023

fix nupkg

1.0.3 - 01/04/2023

fix nupkg

1.0.2 - 01/04/2023

fix doc

1.0.1 - 01/04/2023

add CommandContext to lambda operations method
add support of abstract classes that inherits from command
rename CommandContext by CommandContext
fix bug command options were always set in delegate for -h

1.0.0 - 03/01/2023

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README.md

README.md

CommandLine.NetCore

Index

Features

Howto

1. Running the command line

2. Testing the integrated help command:

3. Configuring the library and a console application built with it

4. Implementing a command

4.1. Implementing a command with a class

Arguments to concrete types mapping of `Do(LambdaExpression expression)` expression parameters:

Flags

Options

Parameters

Exemple of the command `help` defined in `CommandLine.NetCore.Commands.CmdLine`:

Exemple of the command `get-info` defined in `CommandLine.NetCore.Example.Commands.GetInfo`:

4.2. Implementing a classless command with a lambda expression

Example of the command `add` defined in `CommandLine.NetCore.Example.Program`:

5. Setup an unique command console app (without command argument)

6. Command classes attributes

7. Debug and troobleshoot

Integrated options

parser traces

parser setup

Versions history

Files

README.md

Latest commit

History

README.md

File metadata and controls

CommandLine.NetCore

Index

Features

Howto

1. Running the command line

2. Testing the integrated help command:

3. Configuring the library and a console application built with it

4. Implementing a command

4.1. Implementing a command with a class

Arguments to concrete types mapping of Do(LambdaExpression expression) expression parameters:

Flags

Options

Parameters

Exemple of the command help defined in CommandLine.NetCore.Commands.CmdLine:

Exemple of the command get-info defined in CommandLine.NetCore.Example.Commands.GetInfo:

4.2. Implementing a classless command with a lambda expression

Example of the command add defined in CommandLine.NetCore.Example.Program:

5. Setup an unique command console app (without command argument)

6. Command classes attributes

7. Debug and troobleshoot

Integrated options

parser traces

parser setup

Versions history

Arguments to concrete types mapping of `Do(LambdaExpression expression)` expression parameters:

Exemple of the command `help` defined in `CommandLine.NetCore.Commands.CmdLine`:

Exemple of the command `get-info` defined in `CommandLine.NetCore.Example.Commands.GetInfo`:

Example of the command `add` defined in `CommandLine.NetCore.Example.Program`: