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|
package command
import (
"errors"
"fmt"
"io"
"strings"
"text/tabwriter"
)
var ErrHelp = errors.New("help requested")
func (n *node) PrintHelp() { _ = n.writeHelp() }
func (n *node) writeHelp() error {
if _, err := fmt.Fprintf(n.out,
"\nUsage:\t%s [-h | --help]%s COMMAND [OPTIONS]\n",
strings.Join(append(n.prefix, n.name), " "), &n.suffix,
); err != nil {
return err
}
if n.child != nil {
if _, err := fmt.Fprint(n.out, "\nCommands:\n"); err != nil {
return err
}
}
tw := tabwriter.NewWriter(n.out, 0, 1, 4, ' ', 0)
if err := n.child.writeCommands(tw); err != nil {
return err
}
if err := tw.Flush(); err != nil {
return err
}
_, err := n.out.Write([]byte{'\n'})
if err == nil {
err = ErrHelp
}
return err
}
func (n *node) writeCommands(w io.Writer) error {
if n == nil {
return nil
}
if n.usage != UsageInternal {
if _, err := fmt.Fprintf(w, "\t%s\t%s\n", n.name, n.usage); err != nil {
return err
}
}
return n.next.writeCommands(w)
}
|
