/usr/lib/python3.5/pty.py is in libpython3.5-stdlib 3.5.1-10.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 | """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 select import select
import os
import tty
__all__ = ["openpty","fork","spawn"]
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)."""
for x in 'pqrstuvwxyzPQRST':
for y in '0123456789abcdef':
pty_name = '/dev/pty' + x + y
try:
fd = os.open(pty_name, os.O_RDWR)
except OSError:
continue
return (fd, '/dev/tty' + x + y)
raise OSError('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."""
result = os.open(tty_name, os.O_RDWR)
try:
from fcntl import ioctl, I_PUSH
except ImportError:
return result
try:
ioctl(result, I_PUSH, "ptem")
ioctl(result, I_PUSH, "ldterm")
except OSError:
pass
return result
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()
except OSError:
# 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)
# Explicitly open the tty to make it become a controlling tty.
tmp_fd = os.open(os.ttyname(STDOUT_FILENO), os.O_RDWR)
os.close(tmp_fd)
else:
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)"""
fds = [master_fd, STDIN_FILENO]
while True:
rfds, wfds, xfds = select(fds, [], [])
if master_fd in rfds:
data = master_read(master_fd)
if not data: # Reached EOF.
fds.remove(master_fd)
else:
os.write(STDOUT_FILENO, data)
if STDIN_FILENO in rfds:
data = stdin_read(STDIN_FILENO)
if not data:
fds.remove(STDIN_FILENO)
else:
_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:
os.execlp(argv[0], *argv)
try:
mode = tty.tcgetattr(STDIN_FILENO)
tty.setraw(STDIN_FILENO)
restore = 1
except tty.error: # This is the same as termios.error
restore = 0
try:
_copy(master_fd, master_read, stdin_read)
except OSError:
if restore:
tty.tcsetattr(STDIN_FILENO, tty.TCSAFLUSH, mode)
os.close(master_fd)
return os.waitpid(pid, 0)[1]
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