From 046346645f5d7039100ec15db11b887d5be7d7f3 Mon Sep 17 00:00:00 2001
From: Alexey Milovidov <milovidov@yandex-team.ru>
Date: Fri, 23 Mar 2018 19:55:35 +0300
Subject: [PATCH] Minor modifications #1959

---
 dbms/src/IO/ReadHelpers.h  |  2 ++
 dbms/src/Server/Client.cpp | 26 +++++++++++++-------------
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/dbms/src/IO/ReadHelpers.h b/dbms/src/IO/ReadHelpers.h
index 875515149b6..2d3b405675f 100644
--- a/dbms/src/IO/ReadHelpers.h
+++ b/dbms/src/IO/ReadHelpers.h
@@ -52,6 +52,8 @@ inline char parseEscapeSequence(char c)
             return '\a';
         case 'b':
             return '\b';
+        case 'e':
+            return '\x1B';      /// \e escape sequence is non standard for C and C++ but supported by gcc and clang.
         case 'f':
             return '\f';
         case 'n':
diff --git a/dbms/src/Server/Client.cpp b/dbms/src/Server/Client.cpp
index 721df841820..d16a5de3b03 100644
--- a/dbms/src/Server/Client.cpp
+++ b/dbms/src/Server/Client.cpp
@@ -33,6 +33,7 @@
 #include <IO/WriteBufferFromFileDescriptor.h>
 #include <IO/WriteBufferFromFile.h>
 #include <IO/ReadBufferFromMemory.h>
+#include <IO/ReadBufferFromString.h>
 #include <IO/ReadHelpers.h>
 #include <IO/WriteHelpers.h>
 #include <DataStreams/AsynchronousBlockInputStream.h>
@@ -340,38 +341,37 @@ private:
 
         Strings keys;
 
-        prompt_by_server_display_name = config().getString("prompt_by_server_display_name.default", "{display_name} :) ");
+        prompt_by_server_display_name = config().getRawString("prompt_by_server_display_name.default", "{display_name} :) ");
 
         config().keys("prompt_by_server_display_name", keys);
 
         for (const String & key : keys)
         {
-            if (key != "default" && server_display_name.find(key) != std::string::npos) 
+            if (key != "default" && server_display_name.find(key) != std::string::npos)
             {
-                prompt_by_server_display_name = config().getString("prompt_by_server_display_name." + key);
+                prompt_by_server_display_name = config().getRawString("prompt_by_server_display_name." + key);
                 break;
             }
         }
 
-        std::map<String, String> terminalCharacters = {
-            { "\\e[",   "\e["  },
-            { "\\33[",  "\33[" },
-            { "\\033[", "\033["},
-            { "\\x1B[", "\x1B["},
-        };
-
-        for (const auto & [key, value]: terminalCharacters)
+        /// Prompt may contain escape sequences including \e[ or \x1b[ sequences to set terminal color.
         {
-            boost::replace_all(prompt_by_server_display_name, key, value);
+            String unescaped_prompt_by_server_display_name;
+            ReadBufferFromString in(prompt_by_server_display_name);
+            readEscapedString(unescaped_prompt_by_server_display_name, in);
+            prompt_by_server_display_name = std::move(unescaped_prompt_by_server_display_name);
         }
 
-        std::map<String, String> environment = {
+        /// Prompt may contain the following substitutions in a form of {name}.
+        std::map<String, String> environment =
+        {
             {"host",         config().getString("host", "localhost")},
             {"port",         config().getString("port", "9000")},
             {"user",         config().getString("user", "default")},
             {"display_name", server_display_name},
         };
 
+        /// Quite suboptimal.
         for (const auto & [key, value]: environment)
         {
             boost::replace_all(prompt_by_server_display_name, "{" + key + "}", value);