From cc108057ffda25a5421e2acc23dc63fe3c7b13d8 Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Mon, 23 Sep 2019 17:55:05 +0200
Subject: [PATCH] redis-cli: ability to start a session in RESP3 mode.

---
 src/redis-cli.c | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/src/redis-cli.c b/src/redis-cli.c
index 38a0b0b7f..47bd11a8a 100644
--- a/src/redis-cli.c
+++ b/src/redis-cli.c
@@ -230,6 +230,7 @@ static struct config {
     int verbose;
     clusterManagerCommand cluster_manager_command;
     int no_auth_warning;
+    int resp3;
 } config;
 
 /* User preferences. */
@@ -751,6 +752,21 @@ static int cliSelect(void) {
     return REDIS_ERR;
 }
 
+/* Select RESP3 mode if redis-cli was started with the -3 option.  */
+static int cliSwitchProto(void) {
+    redisReply *reply;
+    if (config.resp3 == 0) return REDIS_OK;
+
+    reply = redisCommand(context,"HELLO 3");
+    if (reply != NULL) {
+        int result = REDIS_OK;
+        if (reply->type == REDIS_REPLY_ERROR) result = REDIS_ERR;
+        freeReplyObject(reply);
+        return result;
+    }
+    return REDIS_ERR;
+}
+
 /* Connect to the server. It is possible to pass certain flags to the function:
  *      CC_FORCE: The connection is performed even if there is already
  *                a connected socket.
@@ -788,11 +804,13 @@ static int cliConnect(int flags) {
          * errors. */
         anetKeepAlive(NULL, context->fd, REDIS_CLI_KEEPALIVE_INTERVAL);
 
-        /* Do AUTH and select the right DB. */
+        /* Do AUTH, select the right DB, switch to RESP3 if needed. */
         if (cliAuth() != REDIS_OK)
             return REDIS_ERR;
         if (cliSelect() != REDIS_OK)
             return REDIS_ERR;
+        if (cliSwitchProto() != REDIS_OK)
+            return REDIS_ERR;
     }
     return REDIS_OK;
 }
@@ -1449,6 +1467,8 @@ static int parseOptions(int argc, char **argv) {
             printf("redis-cli %s\n", version);
             sdsfree(version);
             exit(0);
+        } else if (!strcmp(argv[i],"-3")) {
+            config.resp3 = 1;
         } else if (CLUSTER_MANAGER_MODE() && argv[i][0] != '-') {
             if (config.cluster_manager_command.argc == 0) {
                 int j = i + 1;
@@ -1529,6 +1549,7 @@ static void usage(void) {
 "  -i <interval>      When -r is used, waits <interval> seconds per command.\n"
 "                     It is possible to specify sub-second times like -i 0.1.\n"
 "  -n <db>            Database number.\n"
+"  -3                 Start session in RESP3 protocol mode.\n"
 "  -x                 Read last argument from STDIN.\n"
 "  -d <delimiter>     Multi-bulk delimiter in for raw formatting (default: \\n).\n"
 "  -c                 Enable cluster mode (follow -ASK and -MOVED redirections).\n"
@@ -1543,7 +1564,9 @@ static void usage(void) {
 "                     --csv is specified, or if you redirect the output to a non\n"
 "                     TTY, it samples the latency for 1 second (you can use\n"
 "                     -i to change the interval), then produces a single output\n"
-"                     and exits.\n"
+"                     and exits.\n",version);
+
+    fprintf(stderr,
 "  --latency-history  Like --latency but tracking latency changes over time.\n"
 "                     Default time interval is 15 sec. Change it using -i.\n"
 "  --latency-dist     Shows latency as a spectrum, requires xterm 256 colors.\n"
@@ -1578,7 +1601,7 @@ static void usage(void) {
 "  --help             Output this help and exit.\n"
 "  --version          Output version and exit.\n"
 "\n",
-    version, REDIS_CLI_DEFAULT_PIPE_TIMEOUT);
+    REDIS_CLI_DEFAULT_PIPE_TIMEOUT);
     /* Using another fprintf call to avoid -Woverlength-strings compile warning */
     fprintf(stderr,
 "Cluster Manager Commands:\n"