Branch data     Line data    Source code

       1                 :            : #ifndef bqtForkPTYHH
       2                 :            : #define bqtForkPTYHH
       3                 :            : /** @file tty/forkpty.hh
       4                 :            :  * @brief Physical frontend to the underlying process (shell).
       5                 :            :  */
       6                 :            : 
       7                 :            : #include <string>
       8                 :            : #include <csignal>
       9                 :            : 
      10                 :            : /** ForkPTY is a communications end point between the terminal emulator
      11                 :            :  * and the underlying operating system.
      12                 :            :  * As the name suggests, it is a wrapper over the forkpty() call.
      13                 :            :  * It launches a shell in the host system.
      14                 :            :  */
      15                 :            : class ForkPTY
      16                 :            : {
      17                 :            : public:
      18                 :            :     /** Constructor. Calls Open() with its parameters. @see Open() */
      19                 :          4 :     ForkPTY(std::size_t width, std::size_t height) { Open(width,height); }
      20                 :            : 
      21                 :            :     /** Destructor. Terminates the subprocess if it is still active. */
      22                 :            :     ~ForkPTY();
      23                 :            : 
      24                 :            :     /** Create a subprocess in a virtual terminal with given dimensions.
      25                 :            :      * If the opening is successful, the file descriptor is set to non-blocking mode.
      26                 :            :      */
      27                 :            :     void Open(std::size_t width, std::size_t height);
      28                 :            : 
      29                 :            :     /** Terminate the subprocess. */
      30                 :            :     void Close();
      31                 :            : 
      32                 :            :     /** @returns true if the subprocess was launched successfully. */
      33                 :            :     bool Active() const;
      34                 :            : 
      35                 :            :     /** @returns the underlying file descriptor. */
      36                 :            :     int getfd() const;
      37                 :            : 
      38                 :            :     /** Try to send the string as input to the subprocess in non-blocking mode.
      39                 :            :      * This function is typically called when the user types something.
      40                 :            :      * @param buffer The string to send to the subprocess; typically whatever the user typed.
      41                 :            :      * @returns the number of bytes written.
      42                 :            :      */
      43                 :            :     int Send(std::string_view buffer);
      44                 :            : 
      45                 :            :     /** Try to receive output from the subprocess in non-blcoking mode.
      46                 :            :      * @returns The string containing raw data that was read.
      47                 :            :      * The second member contains the length of the string if successful,
      48                 :            :      * or -1 if read was unsuccesful.
      49                 :            :      */
      50                 :            :     std::pair<std::string,int> Recv();
      51                 :            : 
      52                 :            :     /** Send a signal to the subprocess. */
      53                 :            :     void Kill(int signal);
      54                 :            : 
      55                 :            :     /** Inform the subprocess (or its virtual terminal) that
      56                 :            :      * the terminal has been resized to the given dimensions.
      57                 :            :      */
      58                 :            :     void Resize(unsigned xsize, unsigned ysize);
      59                 :            : 
      60                 :            : private:
      61                 :            :     int fd = -1, pid = -1;
      62                 :            : };
      63                 :            : 
      64                 :            : #endif