urfave cli 命令包
官方文档 : https://godoc.org/github.com/urfave/cli 提供了一个命令行框架。
go get github.com/urfave/cli
import "github.com/urfave/cli"
导入包
cli.NewApp()创建一个实例
调用Run()方法就实现了一个最基本的命令行程序了
app.Action 指定入口函数
package main
import (
"os"
"github.com/urfave/cli"
)
func main() {
app := cli.NewApp()
app.Name = "greet"
app.Usage = "say a greeting"
app.Action = func(c *cli.Context) error {
println("Greetings")
return nil
}
app.Run(os.Args)
}
运行1:
go run main.go --help
NAME:
greet - say a greeting
USAGE:
main.exe [global options] command [command options] [arguments…]
VERSION:
0.0.0
COMMANDS:
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
–help, -h show help
–version, -v print the version
运行2:
go run main.go
Greetings
Flag 使用
package main
import (
"fmt"
"os"
"github.com/urfave/cli"
)
func main() {
var m_port int
app := cli.NewApp()
app.Name = "greet" // 指定程序名称
app.Usage = "say a greeting" // 程序功能描述
app.Flags = []cli.Flag{
cli.IntFlag{
Name: "port, p", // 配置名称
Value: 8000, // 缺省配置值
Usage: "listening port", // 配置描述
Destination: &m_port, // 保存配置值
},
}
app.Action = func(c *cli.Context) error {
println("Greetings")
fmt.Println(c.Int("port"))
fmt.Println(m_port)
return nil
}
app.Run(os.Args)
}
运行1:
go run main.go --help
NAME:
greet - say a greeting
USAGE:
main.exe [global options] command [command options] [arguments…]
VERSION:
0.0.0
COMMANDS:
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
–port value, -p value listening port (default: 8000)
–help, -h show help
–version, -v print the version
运行2:
go run main.go
Greetings
8000
8000
运行3:
go run main.go --port=8080
Greetings
8080
8080
Command 使用
package main
import (
"fmt"
"os"
"github.com/urfave/cli"
)
func main() {
var m_port int
app := cli.NewApp()
app.Name = "greet" // 指定程序名称
app.Usage = "say a greeting" // 程序功能描述
app.Flags = []cli.Flag{
cli.IntFlag{
Name: "port, p", // 配置名称
Value: 8000, // 缺省配置值
Usage: "listening port", // 配置描述
Destination: &m_port, // 保存配置值
},
}
app.Commands = []cli.Command{
{
Name: "add", //命令名称
Aliases: []string{"a"}, // 命令的别名列表
Usage: "calc 1+1", // 命令描述
Category: "arithmetic", // 命令所属的类别
Action: func(c *cli.Context) error { // 函数入口
fmt.Println("1 + 1 = ", 1+1)
return nil
},
},
{
Name: "sub",
Aliases: []string{"s"},
Usage: "calc 5-3",
Category: "arithmetic",
Action: func(c *cli.Context) error {
fmt.Println("5 - 3 = ", 5-3)
return nil
},
},
{
Name: "db",
Usage: "database operations",
Category: "database",
Subcommands: []cli.Command{ // 子命令列表
{
Name: "insert",
Usage: "insert data",
Action: func(c *cli.Context) error {
fmt.Println("insert subcommand")
return nil
},
},
{
Name: "delete",
Usage: "delete data",
Action: func(c *cli.Context) error {
fmt.Println("delete subcommand")
return nil
},
},
},
},
}
app.Action = func(c *cli.Context) error {
println("Greetings")
fmt.Println(c.Int("port"))
fmt.Println(m_port)
return nil
}
app.Run(os.Args)
}
运行1:
go run main.go --help
NAME:
greet - say a greeting
USAGE:
main.exe [global options] command [command options] [arguments…]
VERSION:
0.0.0
COMMANDS:
help, h Shows a list of commands or help for one command
arithmetic:
add, a calc 1+1
sub, s calc 5-3
database:
db database operations
GLOBAL OPTIONS:
–port value, -p value listening port (default: 8000)
–help, -h show help
–version, -v print the version
运行2:
go run main.go db --help
NAME:
greet db - database operations
USAGE:
greet db command [command options] [arguments…]
COMMANDS:
insert insert data
delete delete data
OPTIONS:
–help, -h show help
运行3:
go run main.go add --help
NAME:
main.exe add - calc 1+1
USAGE:
main.exe add [arguments…]
CATEGORY:
arithmetic
运行4:
go run main.go --port 8080
Greetings
8080
8080
运行5:
go run main.go add
1 + 1 = 2
运行6:
go run main.go db insert
insert subcommand
运行7:
go run main.go --port=8080 add db insert
1 + 1 = 2
运行8:
go run main.go add db insert
1 + 1 = 2
运行9:
go run main.go
Greetings
8000
8000
高级用法
package main
import (
"fmt"
"os"
"github.com/urfave/cli"
)
func main() {
app := cli.NewApp()
app.Name = "greet" // 指定程序名称
app.Usage = "say a greeting" // 程序功能描述
app.Flags = []cli.Flag{
cli.IntFlag{
Name: "port, p", // 配置名称
Value: 8000, // 缺省配置值
Usage: "listening port", // 配置描述
},
}
app.Action = MigrateFlags(print1)
app.Commands = []cli.Command{
{
Name: "add", //命令名称
Aliases: []string{"a"}, // 命令的别名列表
Usage: "calc 1+1", // 命令描述
Category: "arithmetic", // 命令所属的类别
Action: MigrateFlags(print2),
},
}
app.Run(os.Args)
}
func MigrateFlags(action func(ctx *cli.Context) error) func(*cli.Context) error {
return func(ctx *cli.Context) error {
for _, name := range ctx.FlagNames() {
if ctx.IsSet(name) {
ctx.GlobalSet(name, ctx.String(name))
}
}
return action(ctx)
}
}
func print1(ctx *cli.Context) error {
fmt.Println("hello world!")
fmt.Println(ctx.Int("port"))
return nil
}
func print2(ctx *cli.Context) error {
fmt.Println("1 + 1 = ", 1+1)
return nil
}
运行1:
go run main.go
hello world!
8000
运行2:
go run main.go add
1 + 1 = 2
type App struct {
// The name of the program. Defaults to path.Base(os.Args[0])
Name string // 程序的名称,缺省值是运行的程序名,可以设置为其名称。
// Full name of command for help, defaults to Name
HelpName string
// Description of the program.
Usage string // 程序功能描述
// Text to override the USAGE section of help
UsageText string
// Description of the program argument format.
ArgsUsage string
// Version of the program
Version string
// Description of the program
Description string
// List of commands to execute
Commands []Command
// List of flags to parse
Flags []Flag // Flag是cli中与解析标志相关的公共接口
// Boolean to enable bash completion commands
EnableBashCompletion bool
// Boolean to hide built-in help command
HideHelp bool
// Boolean to hide built-in version flag and the VERSION section of help
HideVersion bool
// An action to execute when the bash-completion flag is set
BashComplete BashCompleteFunc
// An action to execute before any subcommands are run, but after the context is ready
// If a non-nil error is returned, no subcommands are run
Before BeforeFunc
// An action to execute after any subcommands are run, but after the subcommand has finished
// It is run even if Action() panics
After AfterFunc
// The action to execute when no subcommands are specified
// Expects a `cli.ActionFunc` but will accept the *deprecated* signature of `func(*cli.Context) {}`
// *Note*: support for the deprecated `Action` signature will be removed in a future version
Action interface{}
// Execute this function if the proper command cannot be found
CommandNotFound CommandNotFoundFunc
// Execute this function if an usage error occurs
OnUsageError OnUsageErrorFunc
// Compilation date
Compiled time.Time
// List of all authors who contributed
Authors []Author
// Copyright of the binary if any
Copyright string
// Name of Author (Note: Use App.Authors, this is deprecated)
Author string
// Email of Author (Note: Use App.Authors, this is deprecated)
Email string
// Writer writer to write output to
Writer io.Writer
// ErrWriter writes error output
ErrWriter io.Writer
// Execute this function to handle ExitErrors. If not provided, HandleExitCoder is provided to
// function as a default, so this is optional.
ExitErrHandler ExitErrHandlerFunc
// Other custom info
Metadata map[string]interface{}
// Carries a function which returns app specific info.
ExtraInfo func() map[string]string
// CustomAppHelpTemplate the text template for app help topic.
// cli.go uses text/template to render templates. You can
// render custom help text by setting this variable.
CustomAppHelpTemplate string
// contains filtered or unexported fields
}
Flag是cli中与解析标志相关的公共接口
type Flag interface {
fmt.Stringer
// Apply Flag settings to the given flag set
Apply(*flag.FlagSet)
GetName() string
}
IntFlag 是 Flag 的一个整型类型,实现了Flag接口。
type IntFlag struct {
Name string // 配置名称
Usage string // 描述该配置的功能
EnvVar string
FilePath string
Hidden bool
Value int // 配置的默认值
Destination *int // 可以保存配置值
}
Command 命令
type Command struct {
// The name of the command
Name string
// short name of the command. Typically one character (deprecated, use `Aliases`)
ShortName string
// A list of aliases for the command
Aliases []string
// A short description of the usage of this command
Usage string
// Custom text to show on USAGE section of help
UsageText string
// A longer explanation of how the command works
Description string
// A short description of the arguments of this command
ArgsUsage string
// The category the command is part of
Category string // 命令所属的类别
// The function to call when checking for bash command completions
BashComplete BashCompleteFunc
// An action to execute before any sub-subcommands are run, but after the context is ready
// If a non-nil error is returned, no sub-subcommands are run
Before BeforeFunc
// An action to execute after any subcommands are run, but after the subcommand has finished
// It is run even if Action() panics
After AfterFunc
// The function to call when this command is invoked
Action interface{}
// Execute this function if a usage error occurs.
OnUsageError OnUsageErrorFunc
// List of child commands
Subcommands Commands
// List of flags to parse
Flags []Flag
// Treat all flags as normal arguments if true
SkipFlagParsing bool
// Skip argument reordering which attempts to move flags before arguments,
// but only works if all flags appear after all arguments. This behavior was
// removed n version 2 since it only works under specific conditions so we
// backport here by exposing it as an option for compatibility.
SkipArgReorder bool
// Boolean to hide built-in help command
HideHelp bool
// Boolean to hide this command from help or completion
Hidden bool
// Boolean to enable short-option handling so user can combine several
// single-character bool arguments into one
// i.e. foobar -o -v -> foobar -ov
UseShortOptionHandling bool
// Full name of command for help, defaults to full command name, including parent commands.
HelpName string
// CustomHelpTemplate the text template for the command help topic.
// cli.go uses text/template to render templates. You can
// render custom help text by setting this variable.
CustomHelpTemplate string
// contains filtered or unexported fields
}
// Context is a type that is passed through to
// each Handler action in a cli application. Context
// can be used to retrieve context-specific Args and
// parsed command-line options.
type Context struct {
App *App
Command Command
shellComplete bool
flagSet *flag.FlagSet
setFlags map[string]bool
parentContext *Context
}