GUACAMOLE-597: Merge add optional flags to OSC for controlling redirected terminal output.

src/terminal/terminal.c

@@ -1551,6 +1551,10 @@ void guac_terminal_flush(guac_terminal* terminal) {
     if (terminal->typescript != NULL)
         guac_terminal_typescript_flush(terminal->typescript);
 
+    /* Flush pipe stream if automatic flushing is enabled */
+    if (terminal->pipe_stream_flags & GUAC_TERMINAL_PIPE_AUTOFLUSH)
+        guac_terminal_pipe_stream_flush(terminal);
+
     /* Flush display state */
     guac_terminal_select_redraw(terminal);
     guac_terminal_commit_cursor(terminal);
@@ -1961,7 +1965,8 @@ int guac_terminal_next_tab(guac_terminal* term, int column) {
     return tabstop;
 }
 
-void guac_terminal_pipe_stream_open(guac_terminal* term, const char* name) {
+void guac_terminal_pipe_stream_open(guac_terminal* term, const char* name,
+        int flags) {
 
     guac_client* client = term->client;
     guac_socket* socket = client->socket;
@@ -1972,13 +1977,14 @@ void guac_terminal_pipe_stream_open(guac_terminal* term, const char* name) {
     /* Allocate and assign new pipe stream */
     term->pipe_stream = guac_client_alloc_stream(client);
     term->pipe_buffer_length = 0;
+    term->pipe_stream_flags = flags;
 
     /* Open new pipe stream */
     guac_protocol_send_pipe(socket, term->pipe_stream, "text/plain", name);
 
     /* Log redirect at debug level */
-    guac_client_log(client, GUAC_LOG_DEBUG,
+    guac_client_log(client, GUAC_LOG_DEBUG, "Terminal output now directed to "
-            "Terminal output now redirected to pipe '%s'.", name);
+            "pipe \"%s\" (flags=%i).", name, flags);
 
 }
 

src/terminal/terminal/terminal.h

@@ -98,6 +98,21 @@
  */
 #define GUAC_TERMINAL_SCHEME_NUMBERED "color"
 
+/**
+ * Flag which specifies that terminal output should be sent to both the current
+ * pipe stream and the user's display. By default, terminal output will be sent
+ * only to the open pipe.
+ */
+#define GUAC_TERMINAL_PIPE_INTERPRET_OUTPUT 1
+
+/**
+ * Flag which forces the open pipe stream to be flushed automatically, whenever
+ * a new frame would be rendered, with only minimal buffering performed between
+ * frames. By default, the contents of the pipe stream will be flushed only
+ * when the buffer is full or the pipe stream is being closed.
+ */
+#define GUAC_TERMINAL_PIPE_AUTOFLUSH 2
+
 typedef struct guac_terminal guac_terminal;
 
 /**
@@ -215,6 +230,16 @@ struct guac_terminal {
      */
     guac_stream* pipe_stream;
 
+    /**
+     * Bitwise OR of all flags which apply to the currently-open pipe stream.
+     * If no pipe stream is open, this value has no meaning, and its contents
+     * are undefined.
+     *
+     * @see GUAC_TERMINAL_PIPE_INTERPRET_OUTPUT
+     * @see GUAC_TERMINAL_PIPE_AUTOFLUSH
+     */
+    int pipe_stream_flags;
+
     /**
      * Buffer of data pending write to the pipe_stream. Data within this buffer
      * will be flushed to the pipe_stream when either (1) the buffer is full
@@ -920,8 +945,16 @@ int guac_terminal_next_tab(guac_terminal* term, int column);
  *
  * @param name
  *     The name of the pipe stream to open.
+ *
+ * @param flags
+ *     A bitwise OR of all integer flags which should apply to the new pipe
+ *     stream.
+ *
+ *     @see GUAC_TERMINAL_PIPE_INTERPRET_OUTPUT
+ *     @see GUAC_TERMINAL_PIPE_AUTOFLUSH
  */
-void guac_terminal_pipe_stream_open(guac_terminal* term, const char* name);
+void guac_terminal_pipe_stream_open(guac_terminal* term, const char* name,
+        int flags);
 
 /**
  * Writes a single byte of data to the pipe stream currently open and

src/terminal/terminal_handlers.c

@@ -135,8 +135,14 @@ int guac_terminal_echo(guac_terminal* term, unsigned char c) {
 
     /* Echo to pipe stream if open and not starting an ESC sequence */
     if (term->pipe_stream != NULL && c != 0x1B) {
+
         guac_terminal_pipe_stream_write(term, c);
+
+        /* Do not render output while pipe is open unless explicitly requested
+         * via flags */
+        if (!(term->pipe_stream_flags & GUAC_TERMINAL_PIPE_INTERPRET_OUTPUT))
             return 0;
+
     }
 
     /* If using non-Unicode mapping, just map straight bytes */
@@ -1141,27 +1147,44 @@ int guac_terminal_download(guac_terminal* term, unsigned char c) {
 
 int guac_terminal_open_pipe_stream(guac_terminal* term, unsigned char c) {
 
-    static char stream_name[2048];
+    static char param[2048];
     static int length = 0;
+    static int flags = 0;
 
     /* Open pipe on ECMA-48 ST (String Terminator) */
     if (c == 0x9C || c == 0x5C || c == 0x07) {
 
-        /* End stream name string */
+        /* End parameter string */
-        stream_name[length++] = '\0';
+        param[length++] = '\0';
         length = 0;
 
-        /* Open new pipe stream */
+        /* Open new pipe stream using final parameter as name */
-        guac_terminal_pipe_stream_open(term, stream_name);
+        guac_terminal_pipe_stream_open(term, param, flags);
 
         /* Return to echo mode */
         term->char_handler = guac_terminal_echo;
 
+        /* Reset tracked flags for sake of any future pipe streams */
+        flags = 0;
+
     }
 
-    /* Otherwise, store character within stream name */
+    /* Interpret all parameters prior to the final parameter as integer
-    else if (length < sizeof(stream_name)-1)
+     * flags which should affect the pipe stream when opened */
-        stream_name[length++] = c;
+    else if (c == ';') {
+
+        /* End parameter string */
+        param[length++] = '\0';
+        length = 0;
+
+        /* Parse parameter string as integer flags */
+        flags |= atoi(param);
+
+    }
+
+    /* Otherwise, store character within parameter */
+    else if (length < sizeof(param)-1)
+        param[length++] = c;
 
     return 0;