src/shell/lscp.cpp

/*
 * LSCP Shell
 *
 * Copyright (c) 2014 Christian Schoenebeck
 *
 * This program is part of LinuxSampler and released under the same terms.
 */

#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <sstream>
#include <string.h>

#include "LSCPClient.h"
#include "KeyboardReader.h"
#include "TerminalCtrl.h"
#include "CFmt.h"
#include "CCursor.h"
#include "TerminalPrinter.h"

#include "../common/global.h"
#include "../common/global_private.h"
#include "../common/Condition.h"

#define LSCP_DEFAULT_HOST "localhost"
#define LSCP_DEFAULT_PORT 8888

using namespace std;
using namespace LinuxSampler;

static LSCPClient* g_client = NULL;
static KeyboardReader* g_keyboardReader = NULL;
static Condition g_todo;
static String g_goodPortion;
static String g_badPortion;
static String g_suggestedPortion;
static int g_linesActive = 0;
static const String g_prompt = "lscp=# ";
static std::vector<String> g_commandHistory;
static int g_commandHistoryIndex = -1;

static void printUsage() {
    cout << "lscp - The LinuxSampler Control Protocol (LSCP) Shell." << endl;
    cout << endl;
    cout << "Usage: lscp [-h HOSTNAME] [-p PORT]" << endl;
    cout << endl;
    cout << "   -h  Host name of LSCP server (default \"" << LSCP_DEFAULT_HOST << "\")." << endl;
    cout << endl;
    cout << "   -p  TCP port number of LSCP server (default " << LSCP_DEFAULT_PORT << ")." << endl;
    cout << endl;
    cout << "   --no-auto-correct  Don't perform auto correction of obvious syntax errors." << endl;
    cout << endl;
}

static void printWelcome() {
    cout << "Welcome to lscp " << VERSION << ", the LinuxSampler Control Protocol (LSCP) shell." << endl;
    cout << endl;
}

static void printPrompt() {
    cout << g_prompt << flush;
}

static int promptOffset() {
    return g_prompt.size();
}

// Called by the network reading thread, whenever new data arrived from the
// network connection.
static void onLSCPClientNewInputAvailable(LSCPClient* client) {
    g_todo.Set(true);
}

// Called by the keyboard reading thread, whenever a key stroke was received.
static void onNewKeyboardInputAvailable(KeyboardReader* reader) {
    g_todo.Set(true);
}

static void autoComplete() {
    if (g_suggestedPortion.empty()) return;
    String s;
    // let the server delete mistaken characters first
    for (int i = 0; i < g_badPortion.size(); ++i) s += '\b';
    // now add the suggested, correct characters
    s += g_suggestedPortion;
    g_suggestedPortion.clear();
    g_client->send(s);
}

static void commandFromHistory(int offset) {
    if (g_commandHistoryIndex + offset < 0 ||
        g_commandHistoryIndex + offset >= g_commandHistory.size()) return;
    g_commandHistoryIndex += offset;
    int len = g_goodPortion.size() + g_badPortion.size();
    // erase current active line
    for (int i = 0; i < len; ++i) g_client->send('\b');
    // transmit new/old line to LSCP server
    String command = g_commandHistory[g_commandHistory.size() - g_commandHistoryIndex - 1];
    g_client->send(command);
}

static void previousCommand() {
    commandFromHistory(1);
}

static void nextCommand() {
    commandFromHistory(-1);
}

static void storeCommandInHistory(const String& sCommand) {
    g_commandHistoryIndex = -1; // reset history index
    // don't save the command if the previous one was the same
    if (g_commandHistory.empty() || g_commandHistory.back() != sCommand)
        g_commandHistory.push_back(sCommand);
}

/**
 * This LSCP shell application is designed as thin client. That means the heavy
 * LSCP grammar evaluation tasks are peformed by the LSCP server and the shell
 * application's task are simply limited to forward individual characters typed
 * by the user to the LSCP server and showing the result of the LSCP server's
 * evaluation to the user on the screen. This has the big advantage that the
 * shell works perfectly with any machine running (some minimum recent version
 * of) LinuxSampler, no matter which precise LSCP version the server side
 * is using. Which reduces the maintenance efforts for the shell application
 * development tremendously.
 *
 * As soon as this application established a TCP connection to a LSCP server, it
 * sends this command to the LSCP server:
 * @code
 * SET SHELL INTERACT 1
 * @endcode
 * which will inform the LSCP server that this LSCP client is actually a LSCP
 * shell application. The shell will then simply forward every single character
 * typed by the user immediately to the LSCP server, which in turn will evaluate
 * every single character typed by the user and will return immediately a
 * specially formatted string to the shell application like (assuming the user's
 * current command line was "CREATE AUasdf"):
 * @code
 * SHU:1:CREATE AU{{GF}}asdf{{CU}}{{SB}}DIO_OUTPUT_DEVICE
 * @endcode
 * which informs this shell application about the result of the LSCP grammar
 * evaluation and allows the shell to easily show that result of the evaluation
 * to the user on the screen. In the example reply above, the prefix "SHU:" just
 * indicates to the shell application that this response line is the result
 * of the latest grammar evaluation, the number followed (here 1) indicates the
 * semantic status of the current command line:
 *
 * - 0: Command line is complete, thus ENTER key may be hit by the user now.
 * - 1: Current command line contains syntax error(s).
 * - 2: Command line is incomplete, but contains no syntax errors so far.
 *
 * Then the actual current command line follows, with special markers:
 *
 * - Left of "{{GF}}" the command line is syntactically correct, right of that
 *   marker the command line is syntactically wrong.
 *
 * - Marker "{{CU}}" indicates the current cursor position of the command line.
 *
 * - Right of "{{SB}}" follows the current auto completion suggestion, so that
 *   string portion was not typed by the user yet, but is expected to be typed
 *   by him next to retain syntax correctness.
 */
int main(int argc, char *argv[]) {
    String host = LSCP_DEFAULT_HOST;
    int port    = LSCP_DEFAULT_PORT;
    bool autoCorrect = true;

    // parse command line arguments
    for (int i = 0; i < argc; ++i) {
        String s = argv[i];
        if (s == "-h" || s == "--host") {
            if (++i >= argc) {
                printUsage();
                return -1;
            }
            host = argv[i];
        } else if (s == "-p" || s == "--port") {
            if (++i >= argc) {
                printUsage();
                return -1;
            }
            port = atoi(argv[i]);
            if (port <= 0) {
                cerr << "Error: invalid port argument \"" << argv[i] << "\"\n";
                return -1;
            }
        } else if (s == "--no-auto-correct") {
            autoCorrect = false;
        } else if (s[0] == '-') { // invalid / unknown command line argument ...
            printUsage();
            return -1;
        }
    }

    // try to connect to the sampler's LSCP server and start a thread for
    // receiving incoming network data from the sampler's LSCP server
    g_client = new LSCPClient;
    g_client->setCallback(onLSCPClientNewInputAvailable);
    if (!g_client->connect(host, port)) return -1;
    String sResponse = g_client->sendCommandSync(
        (autoCorrect) ? "SET SHELL AUTO_CORRECT 1" : "SET SHELL AUTO_CORRECT 0"
    );
    sResponse = g_client->sendCommandSync("SET SHELL INTERACT 1");
    if (sResponse.substr(0, 2) != "OK") {
        cerr << "Error: sampler too old, it does not support shell instructions\n";
        return -1;
    }
    
    printWelcome();
    printPrompt();

    // start a thread for reading from the local text input keyboard
    // (keyboard echo will be disabled as well to have a clean control on what
    // is appearing on the screen)
    g_keyboardReader = new KeyboardReader;
    g_keyboardReader->setCallback(onNewKeyboardInputAvailable);
    g_keyboardReader->startReading();

    int iKbdEscapeCharsExpected = 0;
    char kbdPrevEscapeChar;

    // main thread's loop
    //
    // This application runs 3 threads:
    //
    // - Keyboard thread: reads constantly on stdin for new characters (which
    //   will block this keyboard thread until new character(s) were typed by
    //   the user) and pushes the typed characters into a FIFO buffer.
    //
    // - Network thread: reads constantly on the TCP connection for new bytes
    //   being sent by the LSCP server (which will block this network thread
    //   until new bytes were received) and pushes the received bytes into a
    //   FIFO buffer.
    //
    // - Main thread: this thread runs in the loop below. The main thread sleeps
    //   (by using the "g_todo" semaphore) until either new keys on the keyboard
    //   were stroke by the user or until new bytes were received from the LSCP
    //   server. The main thread will then accordingly send the typed characters
    //   to the LSCP server and/or show the result of the LSCP server's latest
    //   evaluation to the user on the screen (by pulling those data from the
    //   other two thread's FIFO buffers).
    while (true) {
        // sleep until either new data from the network or from keyboard arrived
        g_todo.WaitIf(false);
        // immediately unset the condition variable and unlock it
        g_todo.Set(false);
        g_todo.Unlock();

        // did network data arrive?
        while (g_client->messageComplete()) {
            String line = *g_client->popLine();
            //printf("line '%s'\n", line.c_str());
            if (line.substr(0,4) == "SHU:") {
                int code = 0, n = 0;
                int res = sscanf(line.c_str(), "SHU:%d:%n", &code, &n);
                if (res >= 1) {                    
                    String s = line.substr(n);

                    // extract portion that is already syntactically correct
                    size_t iGood = s.find(LSCP_SHK_GOOD_FRONT);
                    String sGood = s.substr(0, iGood);
                    if (sGood.find(LSCP_SHK_CURSOR) != string::npos)
                        sGood.erase(sGood.find(LSCP_SHK_CURSOR), strlen(LSCP_SHK_CURSOR)); // erase cursor marker

                    // extract portion that was written syntactically incorrect
                    String sBad = s.substr(iGood + strlen(LSCP_SHK_GOOD_FRONT));
                    if (sBad.find(LSCP_SHK_CURSOR) != string::npos)
                        sBad.erase(sBad.find(LSCP_SHK_CURSOR), strlen(LSCP_SHK_CURSOR)); // erase cursor marker
                    if (sBad.find(LSCP_SHK_SUGGEST_BACK) != string::npos)
                        sBad.erase(sBad.find(LSCP_SHK_SUGGEST_BACK)); // erase auto suggestion portion
                    if (sBad.find(LSCP_SHK_POSSIBILITIES_BACK) != string::npos)
                        sBad.erase(sBad.find(LSCP_SHK_POSSIBILITIES_BACK)); // erase possibilities portion

                    // extract portion that is suggested for auto completion
                    String sSuggest;
                    if (s.find(LSCP_SHK_SUGGEST_BACK) != string::npos) {
                        sSuggest = s.substr(s.find(LSCP_SHK_SUGGEST_BACK) + strlen(LSCP_SHK_SUGGEST_BACK));
                        if (sSuggest.find(LSCP_SHK_CURSOR) != string::npos)
                            sSuggest.erase(sSuggest.find(LSCP_SHK_CURSOR), strlen(LSCP_SHK_CURSOR)); // erase cursor marker
                        if (sSuggest.find(LSCP_SHK_POSSIBILITIES_BACK) != string::npos)
                            sSuggest.erase(sSuggest.find(LSCP_SHK_POSSIBILITIES_BACK)); // erase possibilities portion
                    }

                    // extract portion that provides all current possibilities
                    // (that is all branches in the current grammar tree)
                    String sPossibilities;
                    if (s.find(LSCP_SHK_POSSIBILITIES_BACK) != string::npos) {
                        sPossibilities = s.substr(s.find(LSCP_SHK_POSSIBILITIES_BACK) + strlen(LSCP_SHK_POSSIBILITIES_BACK));
                    }

                    // extract current cursor position
                    int cursorColumn = sGood.size();
                    String sCursor = s;
                    if (sCursor.find(LSCP_SHK_GOOD_FRONT) != string::npos)
                        sCursor.erase(sCursor.find(LSCP_SHK_GOOD_FRONT), strlen(LSCP_SHK_GOOD_FRONT)); // erase good/bad marker
                    if (sCursor.find(LSCP_SHK_SUGGEST_BACK) != string::npos)
                        sCursor.erase(sCursor.find(LSCP_SHK_SUGGEST_BACK), strlen(LSCP_SHK_SUGGEST_BACK)); // erase suggestion marker
                    if (sCursor.find(LSCP_SHK_CURSOR) != string::npos)
                        cursorColumn = sCursor.find(LSCP_SHK_CURSOR);

                    // store those informations globally for the auto-completion
                    // feature
                    g_goodPortion      = sGood;
                    g_badPortion       = sBad;
                    g_suggestedPortion = sSuggest;

                    //printf("line '%s' good='%s' bad='%s' suggested='%s' cursor=%d\n", line.c_str(), sGood.c_str(), sBad.c_str(), sSuggest.c_str(), cursorColumn);

                    // clear current command line on screen
                    // (which may have been printed over several lines)
                    CCursor cursor = CCursor::now().toColumn(0).clearLine();
                    for (int i = 0; i < g_linesActive; ++i)
                        cursor = cursor.down().clearLine();
                    if (g_linesActive) cursor = cursor.up(g_linesActive).toColumn(0);
                    printPrompt();

                    // print out the gathered informations on the screen
                    TerminalPrinter p;
                    CFmt cfmt;
                    if (code == LSCP_SHU_COMPLETE) cfmt.bold().green();
                    else cfmt.bold().white();
                    p << sGood;
                    cfmt.reset().red();
                    p << sBad;
                    cfmt.bold().yellow();
                    p << sSuggest;
                    if (!sPossibilities.empty())
                        p << " <- " << sPossibilities;

                    // move cursor back to the appropriate input position in
                    // the command line (which may be several lines above)
                    g_linesActive = p.linesAdvanced();
                    if (p.linesAdvanced()) cursor.up(p.linesAdvanced());
                    cursor.toColumn(cursorColumn + promptOffset());
                }
            } else if (line.substr(0,2) == "OK") { // single-line response expected ...
                cout << endl << flush;
                CFmt cfmt;
                cfmt.green();
                cout << line.substr(0,2) << flush;
                cfmt.reset();
                cout << line.substr(2) << endl << flush;
                printPrompt();
            } else if (line.substr(0,3) == "WRN") { // single-line response expected ...
                cout << endl << flush;
                CFmt cfmt;
                cfmt.yellow();
                cout << line.substr(0,3) << flush;
                cfmt.reset();
                cout << line.substr(3) << endl << flush;
                printPrompt();
            } else if (line.substr(0,3) == "ERR") { // single-line response expected ...
                cout << endl << flush;
                CFmt cfmt;
                cfmt.bold().red();
                cout << line.substr(0,3) << flush;
                cfmt.reset();
                cout << line.substr(3) << endl << flush;
                printPrompt();
            } else if (g_client->multiLine()) { // multi-line response expected ...
                cout << endl << flush;
                while (true) {                   
                   cout << line << endl << flush;
                   if (line.substr(0, 1) == ".") break;
                   if (!g_client->lineAvailable()) break;
                   line = *g_client->popLine();
                }
                printPrompt();
            } else {
                cout << endl << line << endl << flush;
                printPrompt();
            }
        }

        // did keyboard input arrive?
        while (g_keyboardReader->charAvailable()) {
            char c = g_keyboardReader->popChar();

            //std::cout << c << "(" << int(c) << ")" << std::endl << std::flush;
            if (iKbdEscapeCharsExpected) { // escape sequence (still) expected now ...
                iKbdEscapeCharsExpected--;
                if (iKbdEscapeCharsExpected) kbdPrevEscapeChar = c;
                else { // escape sequence is complete ...
                    if (kbdPrevEscapeChar == 91 && c == 65) // up key
                        previousCommand();
                    else if (kbdPrevEscapeChar == 91 && c == 66) // down key
                        nextCommand();
                    else if (kbdPrevEscapeChar == 91 && c == 68) // left key
                        g_client->send(2); // custom usage of this ASCII code
                    else if (kbdPrevEscapeChar == 91 && c == 67) // right key
                        g_client->send(3); // custom usage of this ASCII code
                }
                continue; // don't send this escape sequence character to LSCP server
            } else if (c == KBD_ESCAPE) { // escape sequence for special keys expected next ...
                iKbdEscapeCharsExpected = 2;
                continue; // don't send ESC character to LSCP server
            } else if (c == KBD_BACKSPACE) {
                c = '\b';
            } else if (c == '\t') { // auto completion ...
                autoComplete();
                continue; // don't send tab character to LSCP server
            } else if (c == '\n') {
                storeCommandInHistory(g_goodPortion + g_badPortion);
            }

            g_client->send(c);
        }
    }

    return 0;
}
1	/*
2	* LSCP Shell
3	*
4	* Copyright (c) 2014 Christian Schoenebeck
5	*
6	* This program is part of LinuxSampler and released under the same terms.
7	*/
8
9	#include <stdio.h>
10	#include <stdlib.h>
11	#include <iostream>
12	#include <sstream>
13	#include <string.h>
14
15	#include "LSCPClient.h"
16	#include "KeyboardReader.h"
17	#include "TerminalCtrl.h"
18	#include "CFmt.h"
19	#include "CCursor.h"
20	#include "TerminalPrinter.h"
21
22	#include "../common/global.h"
23	#include "../common/global_private.h"
24	#include "../common/Condition.h"
25
26	#define LSCP_DEFAULT_HOST "localhost"
27	#define LSCP_DEFAULT_PORT 8888
28
29	using namespace std;
30	using namespace LinuxSampler;
31
32	static LSCPClient* g_client = NULL;
33	static KeyboardReader* g_keyboardReader = NULL;
34	static Condition g_todo;
35	static String g_goodPortion;
36	static String g_badPortion;
37	static String g_suggestedPortion;
38	static int g_linesActive = 0;
39	static const String g_prompt = "lscp=# ";
40	static std::vector<String> g_commandHistory;
41	static int g_commandHistoryIndex = -1;
42
43	static void printUsage() {
44	cout << "lscp - The LinuxSampler Control Protocol (LSCP) Shell." << endl;
45	cout << endl;
46	cout << "Usage: lscp [-h HOSTNAME] [-p PORT]" << endl;
47	cout << endl;
48	cout << " -h Host name of LSCP server (default \"" << LSCP_DEFAULT_HOST << "\")." << endl;
49	cout << endl;
50	cout << " -p TCP port number of LSCP server (default " << LSCP_DEFAULT_PORT << ")." << endl;
51	cout << endl;
52	cout << " --no-auto-correct Don't perform auto correction of obvious syntax errors." << endl;
53	cout << endl;
54	}
55
56	static void printWelcome() {
57	cout << "Welcome to lscp " << VERSION << ", the LinuxSampler Control Protocol (LSCP) shell." << endl;
58	cout << endl;
59	}
60
61	static void printPrompt() {
62	cout << g_prompt << flush;
63	}
64
65	static int promptOffset() {
66	return g_prompt.size();
67	}
68
69	// Called by the network reading thread, whenever new data arrived from the
70	// network connection.
71	static void onLSCPClientNewInputAvailable(LSCPClient* client) {
72	g_todo.Set(true);
73	}
74
75	// Called by the keyboard reading thread, whenever a key stroke was received.
76	static void onNewKeyboardInputAvailable(KeyboardReader* reader) {
77	g_todo.Set(true);
78	}
79
80	static void autoComplete() {
81	if (g_suggestedPortion.empty()) return;
82	String s;
83	// let the server delete mistaken characters first
84	for (int i = 0; i < g_badPortion.size(); ++i) s += '\b';
85	// now add the suggested, correct characters
86	s += g_suggestedPortion;
87	g_suggestedPortion.clear();
88	g_client->send(s);
89	}
90
91	static void commandFromHistory(int offset) {
92	if (g_commandHistoryIndex + offset < 0 \|\|
93	g_commandHistoryIndex + offset >= g_commandHistory.size()) return;
94	g_commandHistoryIndex += offset;
95	int len = g_goodPortion.size() + g_badPortion.size();
96	// erase current active line
97	for (int i = 0; i < len; ++i) g_client->send('\b');
98	// transmit new/old line to LSCP server
99	String command = g_commandHistory[g_commandHistory.size() - g_commandHistoryIndex - 1];
100	g_client->send(command);
101	}
102
103	static void previousCommand() {
104	commandFromHistory(1);
105	}
106
107	static void nextCommand() {
108	commandFromHistory(-1);
109	}
110
111	static void storeCommandInHistory(const String& sCommand) {
112	g_commandHistoryIndex = -1; // reset history index
113	// don't save the command if the previous one was the same
114	if (g_commandHistory.empty() \|\| g_commandHistory.back() != sCommand)
115	g_commandHistory.push_back(sCommand);
116	}
117
118	/**
119	* This LSCP shell application is designed as thin client. That means the heavy
120	* LSCP grammar evaluation tasks are peformed by the LSCP server and the shell
121	* application's task are simply limited to forward individual characters typed
122	* by the user to the LSCP server and showing the result of the LSCP server's
123	* evaluation to the user on the screen. This has the big advantage that the
124	* shell works perfectly with any machine running (some minimum recent version
125	* of) LinuxSampler, no matter which precise LSCP version the server side
126	* is using. Which reduces the maintenance efforts for the shell application
127	* development tremendously.
128	*
129	* As soon as this application established a TCP connection to a LSCP server, it
130	* sends this command to the LSCP server:
131	* @code
132	* SET SHELL INTERACT 1
133	* @endcode
134	* which will inform the LSCP server that this LSCP client is actually a LSCP
135	* shell application. The shell will then simply forward every single character
136	* typed by the user immediately to the LSCP server, which in turn will evaluate
137	* every single character typed by the user and will return immediately a
138	* specially formatted string to the shell application like (assuming the user's
139	* current command line was "CREATE AUasdf"):
140	* @code
141	* SHU:1:CREATE AU{{GF}}asdf{{CU}}{{SB}}DIO_OUTPUT_DEVICE
142	* @endcode
143	* which informs this shell application about the result of the LSCP grammar
144	* evaluation and allows the shell to easily show that result of the evaluation
145	* to the user on the screen. In the example reply above, the prefix "SHU:" just
146	* indicates to the shell application that this response line is the result
147	* of the latest grammar evaluation, the number followed (here 1) indicates the
148	* semantic status of the current command line:
149	*
150	* - 0: Command line is complete, thus ENTER key may be hit by the user now.
151	* - 1: Current command line contains syntax error(s).
152	* - 2: Command line is incomplete, but contains no syntax errors so far.
153	*
154	* Then the actual current command line follows, with special markers:
155	*
156	* - Left of "{{GF}}" the command line is syntactically correct, right of that
157	* marker the command line is syntactically wrong.
158	*
159	* - Marker "{{CU}}" indicates the current cursor position of the command line.
160	*
161	* - Right of "{{SB}}" follows the current auto completion suggestion, so that
162	* string portion was not typed by the user yet, but is expected to be typed
163	* by him next to retain syntax correctness.
164	*/
165	int main(int argc, char *argv[]) {
166	String host = LSCP_DEFAULT_HOST;
167	int port = LSCP_DEFAULT_PORT;
168	bool autoCorrect = true;
169
170	// parse command line arguments
171	for (int i = 0; i < argc; ++i) {
172	String s = argv[i];
173	if (s == "-h" \|\| s == "--host") {
174	if (++i >= argc) {
175	printUsage();
176	return -1;
177	}
178	host = argv[i];
179	} else if (s == "-p" \|\| s == "--port") {
180	if (++i >= argc) {
181	printUsage();
182	return -1;
183	}
184	port = atoi(argv[i]);
185	if (port <= 0) {
186	cerr << "Error: invalid port argument \"" << argv[i] << "\"\n";
187	return -1;
188	}
189	} else if (s == "--no-auto-correct") {
190	autoCorrect = false;
191	} else if (s[0] == '-') { // invalid / unknown command line argument ...
192	printUsage();
193	return -1;
194	}
195	}
196
197	// try to connect to the sampler's LSCP server and start a thread for
198	// receiving incoming network data from the sampler's LSCP server
199	g_client = new LSCPClient;
200	g_client->setCallback(onLSCPClientNewInputAvailable);
201	if (!g_client->connect(host, port)) return -1;
202	String sResponse = g_client->sendCommandSync(
203	(autoCorrect) ? "SET SHELL AUTO_CORRECT 1" : "SET SHELL AUTO_CORRECT 0"
204	);
205	sResponse = g_client->sendCommandSync("SET SHELL INTERACT 1");
206	if (sResponse.substr(0, 2) != "OK") {
207	cerr << "Error: sampler too old, it does not support shell instructions\n";
208	return -1;
209	}
210
211	printWelcome();
212	printPrompt();
213
214	// start a thread for reading from the local text input keyboard
215	// (keyboard echo will be disabled as well to have a clean control on what
216	// is appearing on the screen)
217	g_keyboardReader = new KeyboardReader;
218	g_keyboardReader->setCallback(onNewKeyboardInputAvailable);
219	g_keyboardReader->startReading();
220
221	int iKbdEscapeCharsExpected = 0;
222	char kbdPrevEscapeChar;
223
224	// main thread's loop
225	//
226	// This application runs 3 threads:
227	//
228	// - Keyboard thread: reads constantly on stdin for new characters (which
229	// will block this keyboard thread until new character(s) were typed by
230	// the user) and pushes the typed characters into a FIFO buffer.
231	//
232	// - Network thread: reads constantly on the TCP connection for new bytes
233	// being sent by the LSCP server (which will block this network thread
234	// until new bytes were received) and pushes the received bytes into a
235	// FIFO buffer.
236	//
237	// - Main thread: this thread runs in the loop below. The main thread sleeps
238	// (by using the "g_todo" semaphore) until either new keys on the keyboard
239	// were stroke by the user or until new bytes were received from the LSCP
240	// server. The main thread will then accordingly send the typed characters
241	// to the LSCP server and/or show the result of the LSCP server's latest
242	// evaluation to the user on the screen (by pulling those data from the
243	// other two thread's FIFO buffers).
244	while (true) {
245	// sleep until either new data from the network or from keyboard arrived
246	g_todo.WaitIf(false);
247	// immediately unset the condition variable and unlock it
248	g_todo.Set(false);
249	g_todo.Unlock();
250
251	// did network data arrive?
252	while (g_client->messageComplete()) {
253	String line = *g_client->popLine();
254	//printf("line '%s'\n", line.c_str());
255	if (line.substr(0,4) == "SHU:") {
256	int code = 0, n = 0;
257	int res = sscanf(line.c_str(), "SHU:%d:%n", &code, &n);
258	if (res >= 1) {
259	String s = line.substr(n);
260
261	// extract portion that is already syntactically correct
262	size_t iGood = s.find(LSCP_SHK_GOOD_FRONT);
263	String sGood = s.substr(0, iGood);
264	if (sGood.find(LSCP_SHK_CURSOR) != string::npos)
265	sGood.erase(sGood.find(LSCP_SHK_CURSOR), strlen(LSCP_SHK_CURSOR)); // erase cursor marker
266
267	// extract portion that was written syntactically incorrect
268	String sBad = s.substr(iGood + strlen(LSCP_SHK_GOOD_FRONT));
269	if (sBad.find(LSCP_SHK_CURSOR) != string::npos)
270	sBad.erase(sBad.find(LSCP_SHK_CURSOR), strlen(LSCP_SHK_CURSOR)); // erase cursor marker
271	if (sBad.find(LSCP_SHK_SUGGEST_BACK) != string::npos)
272	sBad.erase(sBad.find(LSCP_SHK_SUGGEST_BACK)); // erase auto suggestion portion
273	if (sBad.find(LSCP_SHK_POSSIBILITIES_BACK) != string::npos)
274	sBad.erase(sBad.find(LSCP_SHK_POSSIBILITIES_BACK)); // erase possibilities portion
275
276	// extract portion that is suggested for auto completion
277	String sSuggest;
278	if (s.find(LSCP_SHK_SUGGEST_BACK) != string::npos) {
279	sSuggest = s.substr(s.find(LSCP_SHK_SUGGEST_BACK) + strlen(LSCP_SHK_SUGGEST_BACK));
280	if (sSuggest.find(LSCP_SHK_CURSOR) != string::npos)
281	sSuggest.erase(sSuggest.find(LSCP_SHK_CURSOR), strlen(LSCP_SHK_CURSOR)); // erase cursor marker
282	if (sSuggest.find(LSCP_SHK_POSSIBILITIES_BACK) != string::npos)
283	sSuggest.erase(sSuggest.find(LSCP_SHK_POSSIBILITIES_BACK)); // erase possibilities portion
284	}
285
286	// extract portion that provides all current possibilities
287	// (that is all branches in the current grammar tree)
288	String sPossibilities;
289	if (s.find(LSCP_SHK_POSSIBILITIES_BACK) != string::npos) {
290	sPossibilities = s.substr(s.find(LSCP_SHK_POSSIBILITIES_BACK) + strlen(LSCP_SHK_POSSIBILITIES_BACK));
291	}
292
293	// extract current cursor position
294	int cursorColumn = sGood.size();
295	String sCursor = s;
296	if (sCursor.find(LSCP_SHK_GOOD_FRONT) != string::npos)
297	sCursor.erase(sCursor.find(LSCP_SHK_GOOD_FRONT), strlen(LSCP_SHK_GOOD_FRONT)); // erase good/bad marker
298	if (sCursor.find(LSCP_SHK_SUGGEST_BACK) != string::npos)
299	sCursor.erase(sCursor.find(LSCP_SHK_SUGGEST_BACK), strlen(LSCP_SHK_SUGGEST_BACK)); // erase suggestion marker
300	if (sCursor.find(LSCP_SHK_CURSOR) != string::npos)
301	cursorColumn = sCursor.find(LSCP_SHK_CURSOR);
302
303	// store those informations globally for the auto-completion
304	// feature
305	g_goodPortion = sGood;
306	g_badPortion = sBad;
307	g_suggestedPortion = sSuggest;
308
309	//printf("line '%s' good='%s' bad='%s' suggested='%s' cursor=%d\n", line.c_str(), sGood.c_str(), sBad.c_str(), sSuggest.c_str(), cursorColumn);
310
311	// clear current command line on screen
312	// (which may have been printed over several lines)
313	CCursor cursor = CCursor::now().toColumn(0).clearLine();
314	for (int i = 0; i < g_linesActive; ++i)
315	cursor = cursor.down().clearLine();
316	if (g_linesActive) cursor = cursor.up(g_linesActive).toColumn(0);
317	printPrompt();
318
319	// print out the gathered informations on the screen
320	TerminalPrinter p;
321	CFmt cfmt;
322	if (code == LSCP_SHU_COMPLETE) cfmt.bold().green();
323	else cfmt.bold().white();
324	p << sGood;
325	cfmt.reset().red();
326	p << sBad;
327	cfmt.bold().yellow();
328	p << sSuggest;
329	if (!sPossibilities.empty())
330	p << " <- " << sPossibilities;
331
332	// move cursor back to the appropriate input position in
333	// the command line (which may be several lines above)
334	g_linesActive = p.linesAdvanced();
335	if (p.linesAdvanced()) cursor.up(p.linesAdvanced());
336	cursor.toColumn(cursorColumn + promptOffset());
337	}
338	} else if (line.substr(0,2) == "OK") { // single-line response expected ...
339	cout << endl << flush;
340	CFmt cfmt;
341	cfmt.green();
342	cout << line.substr(0,2) << flush;
343	cfmt.reset();
344	cout << line.substr(2) << endl << flush;
345	printPrompt();
346	} else if (line.substr(0,3) == "WRN") { // single-line response expected ...
347	cout << endl << flush;
348	CFmt cfmt;
349	cfmt.yellow();
350	cout << line.substr(0,3) << flush;
351	cfmt.reset();
352	cout << line.substr(3) << endl << flush;
353	printPrompt();
354	} else if (line.substr(0,3) == "ERR") { // single-line response expected ...
355	cout << endl << flush;
356	CFmt cfmt;
357	cfmt.bold().red();
358	cout << line.substr(0,3) << flush;
359	cfmt.reset();
360	cout << line.substr(3) << endl << flush;
361	printPrompt();
362	} else if (g_client->multiLine()) { // multi-line response expected ...
363	cout << endl << flush;
364	while (true) {
365	cout << line << endl << flush;
366	if (line.substr(0, 1) == ".") break;
367	if (!g_client->lineAvailable()) break;
368	line = *g_client->popLine();
369	}
370	printPrompt();
371	} else {
372	cout << endl << line << endl << flush;
373	printPrompt();
374	}
375	}
376
377	// did keyboard input arrive?
378	while (g_keyboardReader->charAvailable()) {
379	char c = g_keyboardReader->popChar();
380
381	//std::cout << c << "(" << int(c) << ")" << std::endl << std::flush;
382	if (iKbdEscapeCharsExpected) { // escape sequence (still) expected now ...
383	iKbdEscapeCharsExpected--;
384	if (iKbdEscapeCharsExpected) kbdPrevEscapeChar = c;
385	else { // escape sequence is complete ...
386	if (kbdPrevEscapeChar == 91 && c == 65) // up key
387	previousCommand();
388	else if (kbdPrevEscapeChar == 91 && c == 66) // down key
389	nextCommand();
390	else if (kbdPrevEscapeChar == 91 && c == 68) // left key
391	g_client->send(2); // custom usage of this ASCII code
392	else if (kbdPrevEscapeChar == 91 && c == 67) // right key
393	g_client->send(3); // custom usage of this ASCII code
394	}
395	continue; // don't send this escape sequence character to LSCP server
396	} else if (c == KBD_ESCAPE) { // escape sequence for special keys expected next ...
397	iKbdEscapeCharsExpected = 2;
398	continue; // don't send ESC character to LSCP server
399	} else if (c == KBD_BACKSPACE) {
400	c = '\b';
401	} else if (c == '\t') { // auto completion ...
402	autoComplete();
403	continue; // don't send tab character to LSCP server
404	} else if (c == '\n') {
405	storeCommandInHistory(g_goodPortion + g_badPortion);
406	}
407
408	g_client->send(c);
409	}
410	}
411
412	return 0;
413	}