cli is a library for implementing powerful command-line interfaces in Go. cli is the library that powers the CLI for Packer, Serf, Consul, Vault, Terraform, and Nomad.
Easy sub-command based CLIs:
cli foo,cli bar, etc.Support for nested subcommands such as
cli foo bar.Optional support for default subcommands so
clidoes something other than error.Support for shell autocompletion of subcommands, flags, and arguments with callbacks in Go. You don't need to write any shell code.
Automatic help generation for listing subcommands
Automatic help flag recognition of
-h,--help, etc.Automatic version flag recognition of
-v,--version.Helpers for interacting with the terminal, such as outputting information, asking for input, etc. These are optional, you can always interact with the terminal however you choose.
Use of Go interfaces/types makes augmenting various parts of the library a piece of cake.
Below is a simple example of creating and running a CLI
package main
import (
"log""os""github.com/mitchellh/cli"
)
funcmain() {
c:=cli.NewCLI("app", "1.0.0")
c.Args=os.Args[1:]
c.Commands=map[string]cli.CommandFactory{
"foo": fooCommandFactory,
"bar": barCommandFactory,
}
exitStatus, err:=c.Run()
iferr!=nil {
log.Println(err)
}
os.Exit(exitStatus)
}