Add Linux Example of embedded-cli (#41)

This example uses raw terminal mode to allow the embedded-cli to work in Linux.

examples/linux-example/main.cpp

@@ -0,0 +1,130 @@
+/**
+ * Simple example of using embedded-cli in Linux application.
+ * Shamelessly stolen from Win32 version and modified to run under Linux
+ * Runs in terminal / console, using stdio, prints entered commands and args
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <termios.h>
+
+#include <iostream>
+#include <string>
+
+#define EMBEDDED_CLI_IMPL
+#include "embedded_cli.h"
+
+static bool exitFlag = false;
+
+void onCommand(const std::string &name, char *tokens);
+
+void onExit(EmbeddedCli *cli, char *args, void *context);
+
+void onHello(EmbeddedCli *cli, char *args, void *context);
+
+void onLed(EmbeddedCli *cli, char *args, void *context);
+
+void onAdc(EmbeddedCli *cli, char *args, void *context);
+
+int main() {
+    /* single character buffer for reading keystrokes */
+    unsigned char c;
+
+    /* Structures to save the terminal settings for original settings & raw mode */
+    struct termios original_stdin;
+    struct termios raw_stdin;
+
+    /* Backup the terminal settings, and switch to raw mode */
+    tcgetattr(STDIN_FILENO, &original_stdin);
+    raw_stdin = original_stdin;
+    cfmakeraw(&raw_stdin);
+    tcsetattr(STDIN_FILENO, TCSANOW, &raw_stdin);
+
+    EmbeddedCli *cli = embeddedCliNewDefault();
+
+    cli->onCommand = [](EmbeddedCli *embeddedCli, CliCommand *command) {
+        embeddedCliTokenizeArgs(command->args);
+        onCommand(command->name == nullptr ? "" : command->name, command->args);
+    };
+    cli->writeChar = [](EmbeddedCli *embeddedCli, char c) {
+    	write(STDOUT_FILENO, &c, 1);
+    };
+
+    embeddedCliAddBinding(cli, {
+            "exit",
+            "Stop CLI and exit",
+            false,
+            nullptr,
+            onExit
+    });
+    embeddedCliAddBinding(cli, {
+            "get-led",
+            "Get current led status",
+            false,
+            nullptr,
+            onLed
+    });
+    embeddedCliAddBinding(cli, {
+            "get-adc",
+            "Get current adc value",
+            false,
+            nullptr,
+            onAdc
+    });
+    embeddedCliAddBinding(cli, {
+            "hello",
+            "Print hello message",
+            true,
+            (void *) "World",
+            onHello
+    });
+
+    std::cout << "Cli is running. Press 'Esc' to exit\r\n";
+    std::cout << "Type \"help\" for a list of commands\r\n";
+    std::cout << "Use backspace and tab to remove chars and autocomplete\r\n";
+
+    embeddedCliProcess(cli);
+
+    while (!exitFlag) {
+	/* grab the next character and feed it to the CLI processor */
+        if(read(STDIN_FILENO,&c,1)>0) {
+     		 embeddedCliReceiveChar(cli, c);
+    		 embeddedCliProcess(cli);
+        }
+        }
+
+    /* restore terminal settings */
+    tcsetattr(STDIN_FILENO, TCSANOW, &original_stdin);
+
+    return 0;
+}
+
+void onCommand(const std::string &name, char *tokens) {
+    std::cout << "Received command: " << name << "\n";
+
+    for (int i = 0; i < embeddedCliGetTokenCount(tokens); ++i) {
+        std::cout << "Arg " << i << ": " << embeddedCliGetToken(tokens, i + 1) << "\n";
+    }
+}
+
+void onExit(EmbeddedCli *cli, char *args, void *context) {
+    exitFlag = true;
+    std::cout << "Cli will shutdown now...\r\n";
+}
+
+void onHello(EmbeddedCli *cli, char *args, void *context) {
+    std::cout << "Hello, ";
+    if (embeddedCliGetTokenCount(args) == 0)
+        std::cout << (const char *) context;
+    else
+        std::cout << embeddedCliGetToken(args, 1);
+    std::cout << "\r\n";
+}
+
+void onLed(EmbeddedCli *cli, char *args, void *context) {
+    std::cout << "Current led brightness: " << std::rand() % 256 << "\r\n";
+}
+
+void onAdc(EmbeddedCli *cli, char *args, void *context) {
+    std::cout << "Current adc readings: " << std::rand() % 1024 << "\r\n";
+}