forked from mystiq/dex
136 lines
2.9 KiB
Go
136 lines
2.9 KiB
Go
|
package main
|
||
|
|
||
|
import (
|
||
|
"flag"
|
||
|
"fmt"
|
||
|
"os"
|
||
|
"strings"
|
||
|
"text/tabwriter"
|
||
|
"text/template"
|
||
|
)
|
||
|
|
||
|
var (
|
||
|
cmdHelp = &command{
|
||
|
Name: "help",
|
||
|
Summary: "Show a list of commands or help for one command",
|
||
|
Usage: "[COMMAND]",
|
||
|
Run: runHelp,
|
||
|
}
|
||
|
|
||
|
globalUsageTemplate *template.Template
|
||
|
commandUsageTemplate *template.Template
|
||
|
templFuncs = template.FuncMap{
|
||
|
"descToLines": func(s string) []string {
|
||
|
// trim leading/trailing whitespace and split into slice of lines
|
||
|
return strings.Split(strings.Trim(s, "\n\t "), "\n")
|
||
|
},
|
||
|
"printOption": func(name, defvalue, usage string) string {
|
||
|
prefix := "--"
|
||
|
if len(name) == 1 {
|
||
|
prefix = "-"
|
||
|
}
|
||
|
return fmt.Sprintf("\n\t%s%s=%s\t%s", prefix, name, defvalue, usage)
|
||
|
},
|
||
|
}
|
||
|
|
||
|
tabOut *tabwriter.Writer
|
||
|
)
|
||
|
|
||
|
func init() {
|
||
|
tabOut = tabwriter.NewWriter(os.Stdout, 0, 8, 1, '\t', 0)
|
||
|
|
||
|
commands = append(commands, cmdHelp)
|
||
|
|
||
|
globalUsageTemplate = template.Must(template.New("global_usage").Funcs(templFuncs).Parse(`
|
||
|
NAME:
|
||
|
{{printf "\t%s - %s" .Executable .Description}}
|
||
|
|
||
|
USAGE:
|
||
|
{{printf "\t%s" .Executable}} [global options] <command> [command options] [arguments...]
|
||
|
|
||
|
COMMANDS:{{range .Commands}}
|
||
|
{{printf "\t%s\t%s" .Name .Summary}}{{end}}
|
||
|
|
||
|
GLOBAL OPTIONS:{{range .Flags}}{{printOption .Name .DefValue .Usage}}{{end}}
|
||
|
|
||
|
Global options can also be configured via upper-case environment variables prefixed with "DEXCTL_"
|
||
|
For example, "some-flag" => "DEXCTL_SOME_FLAG"
|
||
|
|
||
|
Run "{{.Executable}} help <command>" for more details on a specific command.
|
||
|
`[1:]))
|
||
|
commandUsageTemplate = template.Must(template.New("command_usage").Funcs(templFuncs).Parse(`
|
||
|
NAME:
|
||
|
{{printf "\t%s - %s" .Cmd.Name .Cmd.Summary}}
|
||
|
|
||
|
USAGE:
|
||
|
{{printf "\t%s %s %s" .Executable .Cmd.Name .Cmd.Usage}}
|
||
|
|
||
|
DESCRIPTION:
|
||
|
{{range $line := descToLines .Cmd.Description}}{{printf "\t%s" $line}}
|
||
|
{{end}}
|
||
|
{{if .CmdFlags}}OPTIONS:{{range .CmdFlags}}
|
||
|
{{printOption .Name .DefValue .Usage}}{{end}}
|
||
|
|
||
|
{{end}}For help on global options run "{{.Executable}} help"
|
||
|
`[1:]))
|
||
|
}
|
||
|
|
||
|
func runHelp(args []string) (exit int) {
|
||
|
if len(args) < 1 {
|
||
|
printGlobalUsage()
|
||
|
return
|
||
|
}
|
||
|
|
||
|
var cmd *command
|
||
|
for _, c := range commands {
|
||
|
if c.Name == args[0] {
|
||
|
cmd = c
|
||
|
break
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if cmd == nil {
|
||
|
stderr("Unrecognized command: %s", args[0])
|
||
|
return 1
|
||
|
}
|
||
|
|
||
|
printCommandUsage(cmd)
|
||
|
return
|
||
|
}
|
||
|
|
||
|
func printGlobalUsage() {
|
||
|
globalUsageTemplate.Execute(tabOut, struct {
|
||
|
Executable string
|
||
|
Commands []*command
|
||
|
Flags []*flag.Flag
|
||
|
Description string
|
||
|
}{
|
||
|
cliName,
|
||
|
commands,
|
||
|
getFlags(globalFS),
|
||
|
cliDescription,
|
||
|
})
|
||
|
tabOut.Flush()
|
||
|
}
|
||
|
|
||
|
func printCommandUsage(cmd *command) {
|
||
|
commandUsageTemplate.Execute(tabOut, struct {
|
||
|
Executable string
|
||
|
Cmd *command
|
||
|
CmdFlags []*flag.Flag
|
||
|
}{
|
||
|
cliName,
|
||
|
cmd,
|
||
|
getFlags(&cmd.Flags),
|
||
|
})
|
||
|
tabOut.Flush()
|
||
|
}
|
||
|
|
||
|
func getFlags(flagset *flag.FlagSet) (flags []*flag.Flag) {
|
||
|
flags = make([]*flag.Flag, 0)
|
||
|
flagset.VisitAll(func(f *flag.Flag) {
|
||
|
flags = append(flags, f)
|
||
|
})
|
||
|
return
|
||
|
}
|