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|
package server
import (
"strings"
"sort"
"log"
)
type cmd struct {
name string
f func (r *request)
}
type node struct {
c *cmd
m map[string]*node
}
var cmds = newNode()
func init() {
newCmd(help, "help")
}
func newNode() *node {
return &node{m: map[string]*node{}}
}
func newCmd(f func (r *request), where string) {
path := strings.Split(where, " ")
node := cmds
for _, name := range path {
if name == "" {
panic("invalid command path")
}
v := node.m[name]
if v == nil {
v = newNode()
node.m[name] = v
}
node = v
}
if node.c != nil {
log.Panicf("handler already registered at '%s'", where)
}
node.c = &cmd{
name: where,
f: f,
}
}
func getCmd(path []string) (*cmd, []string) {
node := cmds
for n, name := range path {
node = node.m[name]
if node == nil {
return nil, nil
}
if node.c != nil {
return node.c, path[n + 1:]
}
}
return nil, nil
}
func help(r *request) {
var ss []string
var walker func ([]string, *node)
walker = func (path []string, node *node) {
if node.c != nil {
ss = append(ss, strings.Join(path, " "))
return
}
n := len(path)
path = append(path, "")
for k, v := range node.m {
path[n] = k
walker(path, v)
}
}
root := cmds
for _, s := range r.args {
root = root.m[s]
if root == nil {
break
}
}
if root == nil {
r.Print("nothing to help")
return
}
if root.c != nil {
r.Print("usage: ", root.c.name, " [...]")
return
}
walker(nil, root)
sort.Strings(ss)
for _, s := range ss {
r.Println(s)
}
}
|
