/* This file is part of Zutty. * Copyright (C) 2020 Tom Szilagyi * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * See the file LICENSE for the full license. */ /* The source code in this file is inspired by code samples in the book *   Advanced Programming in the UNIX Environment, 3rd Edition *   by W. Richard Stevens & Stephen A. Rago *   Addison-Wesley, 2013 * * The original example code of the book is available from *   http://www.apuebook.com/code3e.html */ #include "log.h"#include "pty.h" #define _POSIX_C_SOURCE 200809L #if defined(SOLARIS) /* Solaris 10 */#define _XOPEN_SOURCE 600#else#define _XOPEN_SOURCE 700#endif #include <errno.h>#include <fcntl.h>#include <stdarg.h>#include <stddef.h>#include <stdio.h>#include <stdlib.h>#include <string.h>#include <sys/stat.h>#include <termios.h> #if defined(BSD) || defined(MACOS) || !defined(TIOCGWINSZ)#include <sys/ioctl.h>#endif #if defined(SOLARIS)#include <stropts.h>#endif namespace zutty{   int   ptym_open (char* pts_name, int pts_namesz)   {      char* ptr;      int fdm;       if ((fdm = posix_openpt (O_RDWR)) < 0)         SYS_ERROR ("can't open master pty: posix_openpt()");      if (grantpt (fdm) < 0) // grant access to slave         SYS_ERROR ("can't open master pty: grantpt()");      if (unlockpt (fdm) < 0) // clear slave's lock flag         SYS_ERROR ("can't open master pty: unlockpt()");      if ((ptr = ptsname (fdm)) == nullptr) // get slave's name         SYS_ERROR ("can't open master pty: ptsname()");       // Return slave name, null-terminated to handle strlen(ptr) > pts_namesz.      strncpy (pts_name, ptr, pts_namesz);      pts_name [pts_namesz - 1] = '\0';      return fdm;   }    int   ptys_open (char* pts_name)   {      int fds = open (pts_name, O_RDWR);      if (fds < 0)         SYS_ERROR ("can't open slave pty: open()");    #if defined(SOLARIS)      // Check if stream is already set up by autopush facility.      int setup;      if ((setup = ioctl (fds, I_FIND, "ldterm")) < 0)         SYS_ERROR ("can't open slave pty: ioctl(I_FIND, ldterm)");       if (setup == 0)      {         if (ioctl (fds, I_PUSH, "ptem") < 0)            SYS_ERROR ("can't open slave pty: ioctl(I_PUSH, ptem)");         if (ioctl (fds, I_PUSH, "ldterm") < 0)            SYS_ERROR ("can't open slave pty: ioctl(I_PUSH, ldterm)");         if (ioctl (fds, I_PUSH, "ttcompat") < 0)            SYS_ERROR ("can't open slave pty: ioctl(I_PUSH, ttcompat)");      }   #endif      return fds;   }    pid_t   pty_fork (int& o_ptyFd, int cols, int rows)   {      pid_t pid;      char pts_name [20];      int fdm = ptym_open (pts_name, sizeof (pts_name));       pid = fork ();       if (pid < 0)      {         return pid;      }      else if (pid == 0) // child process      {         if (setsid () < 0)            SYS_ERROR ("setsid");          // System V acquires controlling terminal on open ().         int fds = ptys_open (pts_name);          close (fdm); // all done with master in child       #if defined(BSD)         // TIOCSCTTY is the BSD way to acquire a controlling terminal.         if (ioctl (fds, TIOCSCTTY, nullptr) < 0)            SYS_ERROR ("TIOCSCTTY");      #endif          // Set the pty slave's window size.         pty_resize (fds, cols, rows);          // Slave becomes stdin/stdout/stderr of child.         redirectFds (fds);       #if defined(LINUX) || defined(MACOS)         // Setup terminal attributes         struct termios term;         if (tcgetattr (STDIN_FILENO, &term) < 0)            SYS_ERROR ("tcgetattr");         term.c_iflag |= IUTF8;         if (tcsetattr (STDIN_FILENO, TCSANOW, &term) < 0)            SYS_ERROR ("tcsetattr");      #endif      }      else // parent process      {         o_ptyFd = fdm;      }      return pid;   }    void pty_resize (int ptyFd, int cols, int rows)   {      struct winsize wsize {};      wsize.ws_col = cols;      wsize.ws_row = rows;      if (ioctl (ptyFd, TIOCSWINSZ, &wsize) < 0)         SYS_ERROR("TIOCSWINSZ on pty");   } } // namespace zutty