Xray-core/main/commands/base/command.go

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2020-11-25 11:01:53 +00:00
// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package base defines shared basic pieces of the commands,
// in particular logging and the Command structure.
package base
import (
"flag"
"fmt"
"os"
"strings"
"sync"
)
// A Command is an implementation of a xray command
// like xray run or xray version.
type Command struct {
// Run runs the command.
// The args are the arguments after the command name.
Run func(cmd *Command, args []string)
// UsageLine is the one-line usage message.
// The words between "go" and the first flag or argument in the line are taken to be the command name.
UsageLine string
// Short is the short description shown in the 'go help' output.
Short string
// Long is the long message shown in the 'go help <this-command>' output.
Long string
// Flag is a set of flags specific to this command.
Flag flag.FlagSet
// CustomFlags indicates that the command will do its own
// flag parsing.
CustomFlags bool
// Commands lists the available commands and help topics.
// The order here is the order in which they are printed by 'go help'.
// Note that subcommands are in general best avoided.
Commands []*Command
}
// LongName returns the command's long name: all the words in the usage line between "go" and a flag or argument,
func (c *Command) LongName() string {
name := c.UsageLine
if i := strings.Index(name, " ["); i >= 0 {
name = name[:i]
}
if name == CommandEnv.Exec {
return ""
}
return strings.TrimPrefix(name, CommandEnv.Exec+" ")
}
// Name returns the command's short name: the last word in the usage line before a flag or argument.
func (c *Command) Name() string {
name := c.LongName()
if i := strings.LastIndex(name, " "); i >= 0 {
name = name[i+1:]
}
return name
}
// Usage prints usage of the Command
func (c *Command) Usage() {
fmt.Fprintf(os.Stderr, "usage: %s\n", c.UsageLine)
fmt.Fprintf(os.Stderr, "Run 'xray help %s' for details.\n", c.LongName())
SetExitStatus(2)
Exit()
}
// Runnable reports whether the command can be run; otherwise
// it is a documentation pseudo-command such as importpath.
func (c *Command) Runnable() bool {
return c.Run != nil
}
// Exit exits with code set with SetExitStatus()
func Exit() {
os.Exit(exitStatus)
}
// Fatalf logs error and exit with code 1
func Fatalf(format string, args ...interface{}) {
Errorf(format, args...)
Exit()
}
// Errorf logs error and set exit status to 1, but not exit
func Errorf(format string, args ...interface{}) {
fmt.Fprintf(os.Stderr, format, args...)
fmt.Fprintln(os.Stderr)
SetExitStatus(1)
}
// ExitIfErrors exits if current status is not zero
func ExitIfErrors() {
if exitStatus != 0 {
Exit()
}
}
var exitStatus = 0
var exitMu sync.Mutex
// SetExitStatus set exit status code
func SetExitStatus(n int) {
exitMu.Lock()
if exitStatus < n {
exitStatus = n
}
exitMu.Unlock()
}
// GetExitStatus get exit status code
func GetExitStatus() int {
return exitStatus
}