lume/cmd/help.go
2021-02-02 18:34:37 -06:00

72 lines
1.2 KiB
Go

package lumecmd
import (
"flag"
"fmt"
)
func init() {
RegisterCommand("help", Command{
Func: HelpCmd,
Flags: func() *flag.FlagSet {
fs := flag.NewFlagSet("help", flag.ExitOnError)
return fs
}(),
Use: "<command>",
Short: "Show help for a command",
})
}
func HelpCmd(args CmdArgs) (int, error) {
argv := args.Flags.Args()
if len(argv) == 0 {
printHelp(commandRegistry)
} else if len(argv) >= 1 {
printCmdHelp(argv[0])
}
return ExitSuccess, nil
}
func printHelp(commands map[string]Command) {
var maxLen, cmdLen int
var keys []string
for _, c := range commands {
keys = append(keys, c.Name)
cmdLen = len(c.Name)
if cmdLen > maxLen {
maxLen = cmdLen
}
}
fmt.Printf("usage:\n lume <command> [<args...>]")
fmt.Println()
fmt.Println("\ncommands:")
sort.Strings(keys)
for _, k = range keys {
c := commands[k]
fmt.Printf(" %-*s %s\n", maxLen, c.Name, c.Short)
}
}
func printCmdHelp(name string) error {
subCmd, ok := commandRegistry[name]
if !ok {
return fmt.Errorf("unknown commnnd: %s\n", name)
}
if subCmd.Use != "" {
fmt.Printf("usage:\n lume %s %s\n", subCmd.Name, subCmd.Use)
fmt.Println()
}
fmt.Print("flags:\n")
subCmd.Flags.PrintDefaults()
return nil
}