fork() -> (pid, master_fd) Fork and make the child a session leader with a controlling terminal.
()
| 82 | return result |
| 83 | |
| 84 | def fork(): |
| 85 | """fork() -> (pid, master_fd) |
| 86 | Fork and make the child a session leader with a controlling terminal.""" |
| 87 | |
| 88 | try: |
| 89 | pid, fd = os.forkpty() |
| 90 | except (AttributeError, OSError): |
| 91 | pass |
| 92 | else: |
| 93 | if pid == CHILD: |
| 94 | try: |
| 95 | os.setsid() |
| 96 | except OSError: |
| 97 | # os.forkpty() already set us session leader |
| 98 | pass |
| 99 | return pid, fd |
| 100 | |
| 101 | master_fd, slave_fd = openpty() |
| 102 | pid = os.fork() |
| 103 | if pid == CHILD: |
| 104 | # Establish a new session. |
| 105 | os.setsid() |
| 106 | os.close(master_fd) |
| 107 | |
| 108 | # Slave becomes stdin/stdout/stderr of child. |
| 109 | os.dup2(slave_fd, STDIN_FILENO) |
| 110 | os.dup2(slave_fd, STDOUT_FILENO) |
| 111 | os.dup2(slave_fd, STDERR_FILENO) |
| 112 | if slave_fd > STDERR_FILENO: |
| 113 | os.close(slave_fd) |
| 114 | |
| 115 | # Explicitly open the tty to make it become a controlling tty. |
| 116 | tmp_fd = os.open(os.ttyname(STDOUT_FILENO), os.O_RDWR) |
| 117 | os.close(tmp_fd) |
| 118 | else: |
| 119 | os.close(slave_fd) |
| 120 | |
| 121 | # Parent and child process. |
| 122 | return pid, master_fd |
| 123 | |
| 124 | def _read(fd): |
| 125 | """Default read function.""" |