cl

README

cl

About

cl is a package for Go to parse command line arguments. It is published on https://github.com/vbsw/cl and https://codeberg.org/vbsw/cl.

Copyright

Copyright 2025, Vitali Baumtrok (vbsw@mailbox.org).

cl is distributed under the Boost Software License, version 1.0. (See accompanying file LICENSE or copy at http://www.boost.org/LICENSE_1_0.txt)

cl is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the Boost Software License for more details.

Usage

Example A

package main

import (
	"fmt"
	"github.com/vbsw/cl"
	"os"
)

func main() {
	osCmdLine := cl.New(os.Args[1:])

	if osCmdLine.Search("--help", "-h").Available() {
		fmt.Println("USAGE")
		fmt.Println("    --help         prints help")
		fmt.Println("    --version      prints version")

	} else if osCmdLine.Search("--version", "-v").Available() {
		fmt.Println("version 1.0.0")

	} else {
		unmatched := osCmdLine.Unmatched()

		if unmatched.Count() > 1 {
			fmt.Println("ERROR too many arguments")

		} else if unmatched.Count() == 1 {
			fmt.Printf("ERROR unknown argument \"%s\"\n", unmatched.Keys[0])
		}
	}
}

Example B

package main

import (
	"fmt"
	"github.com/vbsw/cl"
	"os"
)

func main() {
	start := "0"
	end := "0"
	osCmdLine := cl.New(os.Args[1:])
	osCmdLine.Delimiter = cl.NewDelimiter("=")

	startArg := osCmdLine.SearchByDelimiter("start")
	endArg := osCmdLine.SearchByDelimiter("end")

	if startArg.Available() {
		start = startArg.Values[0]
		end = start
	}
	if endArg.Available() {
		end = endArg.Values[0]
	}
	fmt.Println("processing from", start, "to", end)
}

References

• https://go.dev/doc/install
• https://git-scm.com/book/en/v2/Getting-Started-Installing-Git

Documentation

Overview

Package cl parses command line arguments.

Index

• type Arguments
  • func (args *Arguments) Available() bool
  • func (args *Arguments) Count() int
• type CommandLine
  • func New(args []string) *CommandLine
  • func (cmdLine *CommandLine) Search(searchTerms ...string) *Arguments
  • func (cmdLine *CommandLine) SearchByDelimiter(searchTerms ...string) *Arguments
  • func (cmdLine *CommandLine) Unmatched() *Arguments
• type Delimiter
  • func NewDelimiter(separators ...string) *Delimiter

Types

type Arguments

type Arguments struct {
	Keys   []string
	Values []string
}

Arguments represents arguments returned by command line search.

func (*Arguments) Available

func (args *Arguments) Available() bool

Available returns true, if at least one argument is available.

func (*Arguments) Count

func (args *Arguments) Count() int

Count returns number of arguments.

type CommandLine

type CommandLine struct {
	Arguments []string
	Matched   []bool
	Delimiter *Delimiter
}

CommandLine represents command line.

func New

func New(args []string) *CommandLine

New returns a new instance of CommandLine.

func (*CommandLine) Search

func (cmdLine *CommandLine) Search(searchTerms ...string) *Arguments

Search compairs CommandLine.Arguments with searchTerms and returns matches.

func (*CommandLine) SearchByDelimiter

func (cmdLine *CommandLine) SearchByDelimiter(searchTerms ...string) *Arguments

SearchByDelimiter compairs CommandLine.Arguments with searchTerms and returns matches. The search considers a delimiter, that separates key and value within parameter. Is Delimiter.HasSpaceSeparator set, then two arguments are treated as one argument with key and value separated by space.

func (*CommandLine) Unmatched

func (cmdLine *CommandLine) Unmatched() *Arguments

Unmatched returns command line arguments that haven't been matched by the search.

type Delimiter

type Delimiter struct {
	Separators        []string
	HasSpaceSeparator bool
	HasEmptySeparator bool
}

Delimiter represents separators between key and value.

func NewDelimiter

func NewDelimiter(separators ...string) *Delimiter

NewDelimiter returns a new instance of Delimiter. An empty separator "" sets the HasEmptySeparator flag for delimiter, and the space separator " " sets the HasSpaceSeparator flag.