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