diff options
| -rw-r--r-- | app.go | 68 | ||||
| -rw-r--r-- | command.go | 34 | ||||
| -rw-r--r-- | example/example.go | 42 | ||||
| -rw-r--r-- | go.mod | 3 |
4 files changed, 147 insertions, 0 deletions
@@ -0,0 +1,68 @@ +package app + +/* +This file is part of the App project. +Copyright (C) 2021 Alexander Kiryukhin <a.kiryukhin@mail.ru> +This program is free software: you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation, either version 3 of the License, or +(at your option) any later version. + +This program 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 +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this program. If not, see <https://www.gnu.org/licenses/>. + +@license GPL-3.0+ <http://spdx.org/licenses/GPL-3.0+> +*/ + +import ( + "fmt" + "os" +) + +type App struct { + commands []Command +} + +var ErrNoCommand = fmt.Errorf("No command provided") + +// New returns new App. +func New(commands []Command) *App { + return &App{commands: commands} +} + +// Start cli application +func (a *App) Start(args []string) error { + if len(args) < 2 { + return a.showHelpAndExit() + } + + cmd := args[1] + for _, c := range a.commands { + if cmd == c.Name() { + fs := c.Flags() + if err := fs.Parse(args[2:]); err != nil { + fs.Usage() + return err + } + if err := c.Run(fs.Args()); err != nil { + return err + } + return nil + } + } + + return a.showHelpAndExit() +} + +func (a *App) showHelpAndExit() error { + fmt.Printf("Usage: %s [command]\nCommands:\n", os.Args[0]) + for _, c := range a.commands { + fmt.Printf("\t%s - %s", c.Name(), c.Usage()) + } + return ErrNoCommand +} diff --git a/command.go b/command.go new file mode 100644 index 0000000..5bf15c8 --- /dev/null +++ b/command.go @@ -0,0 +1,34 @@ +package app + +/* +This file is part of the App project. +Copyright (C) 2021 Alexander Kiryukhin <a.kiryukhin@mail.ru> +This program is free software: you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation, either version 3 of the License, or +(at your option) any later version. + +This program 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 +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this program. If not, see <https://www.gnu.org/licenses/>. + +@license GPL-3.0+ <http://spdx.org/licenses/GPL-3.0+> +*/ + +import "flag" + +// Command represents top level command of cli application +type Command interface { + // Name returns name of command + Name() string + // Usage returns short help to command + Usage() string + // Flags returns FlagSet with flags for current command + Flags() *flag.FlagSet + // Run command + Run(args []string) error +} diff --git a/example/example.go b/example/example.go new file mode 100644 index 0000000..096e2b2 --- /dev/null +++ b/example/example.go @@ -0,0 +1,42 @@ +package app_test + +import ( + "flag" + "fmt" + "os" + + "github.com/neonxp/app" +) + +func ExampleApp() { + app := app.New(commands) + if err := app.Start(os.Args); err != nil { + fmt.Println(err) + os.Exit(1) + } +} + +var commands = []app.Command{} + +type exampleCommand struct { + test string +} + +func (c *exampleCommand) Name() string { + return "example" +} + +func (c *exampleCommand) Usage() string { + return "just example command" +} + +func (c *exampleCommand) Flags() *flag.FlagSet { + fs := flag.NewFlagSet(c.Name(), flag.ExitOnError) + fs.StringVar(&c.test, "test", "value", "test flag") + return fs +} + +func (c *exampleCommand) Run(args []string) error { + fmt.Printf("Runned %s command with flag -test=%s and args: %v", c.Name(), c.test, args) + return nil +} @@ -0,0 +1,3 @@ +module github.com/neonxp/app + +go 1.16 |