add help support in CLI

cmd/ledis-cli/const.go

@@ -0,0 +1,84 @@
+package main
+
+var helpCommands = [][]string{
+	{"DECR", "key", "KV"},
+	{"DECRBY", "key decrement", "KV"},
+	{"DEL", "key [key ...]", "KV"},
+	{"EXISTS", "key", "KV"},
+	{"GET", "key", "KV"},
+	{"GETSET", " key value", "KV"},
+	{"INCR", "key", "KV"},
+	{"INCRBY", "key increment", "KV"},
+	{"MGET", "key [key ...]", "KV"},
+	{"MSET", "key value [key value ...]", "KV"},
+	{"SET", "key value", "KV"},
+	{"SETNX", "key value", "KV"},
+	{"EXPIRE", "key seconds", "KV"},
+	{"EXPIREAT", "key timestamp", "KV"},
+	{"TTL", "PERSIST", "KV"},
+	{"HDEL", "key field [field ...]", "Hash"},
+	{"HEXISTS", "key field", "Hash"},
+	{"HGET", "key field", "Hash"},
+	{"HGETALL", "key", "Hash"},
+	{"HINCRBY", "key field increment", "Hash"},
+	{"HKEYS", "key", "Hash"},
+	{"HLEN", "key", "Hash"},
+	{"HMGET", "key field [field ...]", "Hash"},
+	{"HMSET", "key field value [field value ...]", "Hash"},
+	{"HSET", "key field value", "Hash"},
+	{"HVALS", "key", "Hash"},
+	{"HCLEAR", "key", "Hash"},
+	{"HMCLEAR", "key [key ...]", "Hash"},
+	{"HEXPIRE", "key seconds", "Hash"},
+	{"HEXPIREAT", "key timestamp", "Hash"},
+	{"HTTL", "key", "Hash"},
+	{"HPERSIST", "key", "Hash"},
+	{"LINDEX", "key index", "List"},
+	{"LLEN", "key", "List"},
+	{"LPOP", "key", "List"},
+	{"LPUSH", "key value [value ...]", "List"},
+	{"LRANGE", "key start stop", "List"},
+	{"RPOP", "key", "List"},
+	{"RPUSH", "key value [value ...]", "List"},
+	{"LCLEAR", "key", "List"},
+	{"LMCLEAR", "key [key ...]", "List"},
+	{"LEXPIRE", "key seconds", "List"},
+	{"LEXPIREAT", "key timestamp", "List"},
+	{"LTTL", "key", "List"},
+	{"LPERSIST", "key", "List"},
+	{"ZADD", "key score member [score member ...]", "ZSet"},
+	{"ZCARD", "key", "ZSet"},
+	{"ZCOUNT", "key min max", "ZSet"},
+	{"ZINCRBY", "key increment member", "ZSet"},
+	{"ZRANGE", "key start stop [WITHSCORES]", "ZSet"},
+	{"ZRANGEBYSCORE", "key min max [WITHSCORES] [LIMIT offset count]", "ZSet"},
+	{"ZRANK", "key member", "ZSet"},
+	{"ZREM", "key member [member ...]", "ZSet"},
+	{"ZREMRANGEBYRANK", "key start stop", "ZSet"},
+	{"ZREMRANGEBYSCORE", "key min max", "ZSet"},
+	{"ZREVRANGEBYSCORE", "key max min  [WITHSCORES][LIMIT offset count]", "ZSet"},
+	{"ZREVRANK", "key member", "ZSet"},
+	{"ZSCORE", "key member", "ZSet"},
+	{"ZCLEAR", "key", "ZSet"},
+	{"ZMCLEAR", "key [key ...]", "ZSet"},
+	{"ZEXPIRE", "key seconds", "ZSet"},
+	{"ZEXPIREAT", "key timestamp", "ZSet"},
+	{"ZTTL", "key", "ZSet"},
+	{"ZPERSIST", "key", "ZSet"},
+	{"BGET", "key", "Bitmap"},
+	{"BGETBIT", "key offset", "Bitmap"},
+	{"BSETBIT", "key offset value", "Bitmap"},
+	{"BMSETBIT", "key offset value [offset value ...]", "Bitmap"},
+	{"BOPT", "operation destkey key [key ...]", "Bitmap"},
+	{"BCOUNT", "key [start end]", "Bitmap"},
+	{"BEXPIRE", "key seconds", "Bitmap"},
+	{"BEXPIREAT", "key timestamp", "Bitmap"},
+	{"BTTL", "key", "Bitmap"},
+	{"BPERSIST", "key", "Bitmap"},
+	{"SLAVEOF", "host port", "Replication"},
+	{"FULLSYNC", "-", "Replication"},
+	{"SYNC", "index offset", "Replication"},
+	{"PING", "-", "Server"},
+	{"ECHO", "message", "Server"},
+	{"SELECT", "index", "Server"},
+}

cmd/ledis-cli/main.go

@@ -58,21 +58,29 @@ func main() {
 			addHistory(cmd)
 
 			args := make([]interface{}, len(cmds[1:]))
+
 			for i := range args {
 				args[i] = strings.Trim(string(cmds[1+i]), "\"'")
 			}
-			r, err := c.Do(cmds[0], args...)
 
-			if err != nil {
-				fmt.Printf("%s", err.Error())
-			} else if nb, _ := strconv.Atoi(cmds[1]); strings.ToLower(cmds[0]) == "select" && nb < 16 {
-				*dbn = nb
-				printReply(cmd, r)
+			cmd := cmds[0]
+			if strings.ToLower(cmd) == "help" || cmd == "?" {
+				printHelp(cmds)
 			} else {
-				printReply(cmd, r)
+				r, err := c.Do(cmds[0], args...)
+
+				if err != nil {
+					fmt.Printf("%s", err.Error())
+				} else if nb, _ := strconv.Atoi(cmds[1]); strings.ToLower(cmds[0]) == "select" && nb < 16 {
+					*dbn = nb
+					printReply(cmd, r)
+				} else {
+					printReply(cmd, r)
+				}
+
+				fmt.Printf("\n")
 			}
 
-			fmt.Printf("\n")
 		}
 	}
 }
@@ -105,3 +113,34 @@ func printReply(cmd string, reply interface{}) {
 		fmt.Printf("invalid ledis reply")
 	}
 }
+
+func printGenericHelp() {
+	msg :=
+		`ledis-cli
+Type:	"help <command>" for help on <command>
+	`
+	fmt.Println(msg)
+}
+
+func printCommandHelp(arr []string) {
+	fmt.Println()
+	fmt.Printf("\t%s %s \n", arr[0], arr[1])
+	fmt.Printf("\tGroup: %s \n", arr[2])
+	fmt.Println()
+}
+
+func printHelp(cmds []string) {
+	args := cmds[1:]
+	if len(args) == 0 {
+		printGenericHelp()
+	} else if len(args) > 1 {
+		fmt.Println()
+	} else {
+		cmd := strings.ToUpper(args[0])
+		for i := 0; i < len(helpCommands); i++ {
+			if helpCommands[i][0] == cmd {
+				printCommandHelp(helpCommands[i])
+			}
+		}
+	}
+}