| """Pseudo terminal utilities.""" |
| |
| # Bugs: No signal handling. Doesn't set slave termios and window size. |
| #Only tested on Linux. |
| # See: W. Richard Stevens. 1992. Advanced Programming in the |
| #UNIX Environment. Chapter 19. |
| # Author: Steen Lumholt -- with additions by Guido. |
| |
| from selectimport select |
| import os, FCNTL |
| import tty |
| |
| STDIN_FILENO=0 |
| STDOUT_FILENO=1 |
| STDERR_FILENO=2 |
| |
| CHILD=0 |
| |
| def openpty(): |
| """openpty() -> (master_fd, slave_fd) |
| Open a pty master/slave pair, using os.openpty() if possible.""" |
| |
| try: |
| return os.openpty() |
| except(AttributeError,OSError): |
| pass |
| master_fd, slave_name= _open_terminal() |
| slave_fd= slave_open(slave_name) |
| return master_fd, slave_fd |
| |
| def master_open(): |
| """master_open() -> (master_fd, slave_name) |
| Open a pty master and return the fd, and the filename of the slave end. |
| Deprecated, use openpty() instead.""" |
| |
| try: |
| master_fd, slave_fd= os.openpty() |
| except(AttributeError,OSError): |
| pass |
| else: |
| slave_name= os.ttyname(slave_fd) |
| os.close(slave_fd) |
| return master_fd, slave_name |
| |
| return _open_terminal() |
| |
| def _open_terminal(): |
| """Open pty master and return (master_fd, tty_name). |
| SGI and generic BSD version, for when openpty() fails.""" |
| try: |
| import sgi |
| exceptImportError: |
| pass |
| else: |
| try: |
| tty_name, master_fd= sgi._getpty(FCNTL.O_RDWR,0666,0) |
| exceptIOError, msg: |
| raise os.error, msg |
| return master_fd, tty_name |
| for xin'pqrstuvwxyzPQRST': |
| for yin'0123456789abcdef': |
| pty_name='/dev/pty'+ x+ y |
| try: |
| fd= os.open(pty_name, FCNTL.O_RDWR) |
| except os.error: |
| continue |
| return(fd,'/dev/tty'+ x+ y) |
| raise os.error,'out of pty devices' |
| |
| def slave_open(tty_name): |
| """slave_open(tty_name) -> slave_fd |
| Open the pty slave and acquire the controlling terminal, returning |
| opened filedescriptor. |
| Deprecated, use openpty() instead.""" |
| |
| return os.open(tty_name, FCNTL.O_RDWR) |
| |
| def fork(): |
| """fork() -> (pid, master_fd) |
| Fork and make the child a session leader with a controlling terminal.""" |
| |
| try: |
| pid, fd= os.forkpty() |
| except(AttributeError,OSError): |
| pass |
| else: |
| if pid== CHILD: |
| try: |
| os.setsid() |
| exceptOSError: |
| # os.forkpty() already set us session leader |
| pass |
| return pid, fd |
| |
| master_fd, slave_fd= openpty() |
| pid= os.fork() |
| if pid== CHILD: |
| # Establish a new session. |
| os.setsid() |
| os.close(master_fd) |
| |
| # Slave becomes stdin/stdout/stderr of child. |
| os.dup2(slave_fd, STDIN_FILENO) |
| os.dup2(slave_fd, STDOUT_FILENO) |
| os.dup2(slave_fd, STDERR_FILENO) |
| if(slave_fd> STDERR_FILENO): |
| os.close(slave_fd) |
| |
| # Parent and child process. |
| return pid, master_fd |
| |
| def _writen(fd, data): |
| """Write all the data to a descriptor.""" |
| while data!='': |
| n= os.write(fd, data) |
| data= data[n:] |
| |
| def _read(fd): |
| """Default read function.""" |
| return os.read(fd,1024) |
| |
| def _copy(master_fd, master_read=_read, stdin_read=_read): |
| """Parent copy loop. |
| Copies |
| pty master -> standard output(master_read) |
| standard input -> pty master(stdin_read)""" |
| while1: |
| rfds, wfds, xfds= select( |
| [master_fd, STDIN_FILENO],[],[]) |
| if master_fdin rfds: |
| data= master_read(master_fd) |
| os.write(STDOUT_FILENO, data) |
| if STDIN_FILENOin rfds: |
| data= stdin_read(STDIN_FILENO) |
| _writen(master_fd, data) |
| |
| def spawn(argv, master_read=_read, stdin_read=_read): |
| """Create a spawned process.""" |
| if type(argv)== type(''): |
| argv=(argv,) |
| pid, master_fd= fork() |
| if pid== CHILD: |
| apply(os.execlp,(argv[0],)+ argv) |
| mode= tty.tcgetattr(STDIN_FILENO) |
| tty.setraw(STDIN_FILENO) |
| try: |
| _copy(master_fd, master_read, stdin_read) |
| except: |
| tty.tcsetattr(STDIN_FILENO, tty.TCSAFLUSH, mode) |
