forked from coreos/fleet
-
Notifications
You must be signed in to change notification settings - Fork 0
/
app.go
145 lines (127 loc) · 2.98 KB
/
app.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
package cli
import (
"fmt"
"io/ioutil"
"os"
"time"
)
// App is the main structure of a cli application. It is recomended that
// and app be created with the cli.NewApp() function
type App struct {
// The name of the program. Defaults to os.Args[0]
Name string
// Description of the program.
Usage string
// Version of the program
Version string
// List of commands to execute
Commands []Command
// List of flags to parse
Flags []Flag
// 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 func(context *Context) error
// The action to execute when no subcommands are specified
Action func(context *Context)
// Compilation date
Compiled time.Time
// Author
Author string
// Author e-mail
Email string
}
// Tries to find out when this binary was compiled.
// Returns the current time if it fails to find it.
func compileTime() time.Time {
info, err := os.Stat(os.Args[0])
if err != nil {
return time.Now()
}
return info.ModTime()
}
// Creates a new cli Application with some reasonable defaults for Name, Usage, Version and Action.
func NewApp() *App {
return &App{
Name: os.Args[0],
Usage: "A new cli application",
Version: "0.0.0",
Action: helpCommand.Action,
Compiled: compileTime(),
Author: "Author",
Email: "unknown@email",
}
}
// Entry point to the cli app. Parses the arguments slice and routes to the proper flag/args combination
func (a *App) Run(arguments []string) error {
// append help to commands
if a.Command(helpCommand.Name) == nil {
a.Commands = append(a.Commands, helpCommand)
}
//append version/help flags
a.appendFlag(BoolFlag{"version, v", "print the version"})
a.appendFlag(BoolFlag{"help, h", "show help"})
// parse flags
set := flagSet(a.Name, a.Flags)
set.SetOutput(ioutil.Discard)
err := set.Parse(arguments[1:])
nerr := normalizeFlags(a.Flags, set)
if nerr != nil {
fmt.Println(nerr)
context := NewContext(a, set, set)
ShowAppHelp(context)
fmt.Println("")
return nerr
}
context := NewContext(a, set, set)
if err != nil {
fmt.Printf("Incorrect Usage.\n\n")
ShowAppHelp(context)
fmt.Println("")
return err
}
if checkHelp(context) {
return nil
}
if checkVersion(context) {
return nil
}
if a.Before != nil {
err := a.Before(context)
if err != nil {
return err
}
}
args := context.Args()
if args.Present() {
name := args.First()
c := a.Command(name)
if c != nil {
return c.Run(context)
}
}
// Run default Action
a.Action(context)
return nil
}
// Returns the named command on App. Returns nil if the command does not exist
func (a *App) Command(name string) *Command {
for _, c := range a.Commands {
if c.HasName(name) {
return &c
}
}
return nil
}
func (a *App) hasFlag(flag Flag) bool {
for _, f := range a.Flags {
if flag == f {
return true
}
}
return false
}
func (a *App) appendFlag(flag Flag) {
if !a.hasFlag(flag) {
a.Flags = append(a.Flags, flag)
}
}