scripts/oepydevshell-internal.py

   1 #!/usr/bin/env python3
   2 #
   3 # Copyright OpenEmbedded Contributors
   4 #
   5 # SPDX-License-Identifier: GPL-2.0-only
   6 #
   7
   8 import os
   9 import sys
  10 import time
  11 import select
  12 import fcntl
  13 import termios
  14 import readline
  15 import signal
  16
  17 def nonblockingfd(fd):
  18     fcntl.fcntl(fd, fcntl.F_SETFL, fcntl.fcntl(fd, fcntl.F_GETFL) | os.O_NONBLOCK)
  19
  20 def echonocbreak(fd):
  21     old = termios.tcgetattr(fd)
  22     old[3] = old[3] | termios.ECHO | termios.ICANON
  23     termios.tcsetattr(fd, termios.TCSADRAIN, old)
  24
  25 def cbreaknoecho(fd):
  26     old = termios.tcgetattr(fd)
  27     old[3] = old[3] &~ termios.ECHO &~ termios.ICANON
  28     termios.tcsetattr(fd, termios.TCSADRAIN, old)
  29
  30 if len(sys.argv) != 3 or sys.argv[1] in ('-h', '--help'):
  31     print('oepydevshell-internal.py: error: the following arguments are required: pty, pid\n'
  32           'Usage: oepydevshell-internal.py pty pid\n\n'
  33           'OpenEmbedded oepydevshell-internal.py - internal script called from meta/classes/devshell.bbclass\n\n'
  34           'arguments:\n'
  35           '  pty                   pty device name\n'
  36           '  pid                   parent process id\n\n'
  37           'options:\n'
  38           '  -h, --help            show this help message and exit\n')
  39     sys.exit(2)
  40
  41 pty = open(sys.argv[1], "w+b", 0)
  42 parent = int(sys.argv[2])
  43
  44 nonblockingfd(pty)
  45 nonblockingfd(sys.stdin)
  46
  47
  48 histfile = os.path.expanduser("~/.oepydevshell-history")
  49 readline.parse_and_bind("tab: complete")
  50 try:
  51     readline.read_history_file(histfile)
  52 except IOError:
  53     pass
  54
  55 try:
  56
  57     i = ""
  58     o = ""
  59     # Need cbreak/noecho whilst in select so we trigger on any keypress
  60     cbreaknoecho(sys.stdin.fileno())
  61     # Send our PID to the other end so they can kill us.
  62     pty.write(str(os.getpid()).encode('utf-8') + b"\n")
  63     while True:
  64         try:
  65             writers = []
  66             if i:
  67                 writers.append(sys.stdout)
  68             (ready, _, _) = select.select([pty, sys.stdin], writers , [], 0)
  69             try:
  70                 if pty in ready:
  71                     readdata = pty.read()
  72                     if readdata:
  73                         i = i + readdata.decode('utf-8')
  74                 if i:
  75                     # Write a page at a time to avoid overflowing output
  76                     # d.keys() is a good way to do that
  77                     sys.stdout.write(i[:4096])
  78                     sys.stdout.flush()
  79                     i = i[4096:]
  80                 if sys.stdin in ready:
  81                     echonocbreak(sys.stdin.fileno())
  82                     o = input().encode('utf-8')
  83                     cbreaknoecho(sys.stdin.fileno())
  84                     pty.write(o + b"\n")
  85             except (IOError, OSError) as e:
  86                 if e.errno == 11:
  87                     continue
  88                 if e.errno == 5:
  89                     sys.exit(0)
  90                 raise
  91             except EOFError:
  92                 sys.exit(0)
  93         except KeyboardInterrupt:
  94             os.kill(parent, signal.SIGINT)
  95
  96 except SystemExit:
  97     pass
  98 except Exception as e:
  99     import traceback
 100     print("Exception in oepydehshell-internal: " + str(e))
 101     traceback.print_exc()
 102     time.sleep(5)
 103 finally:
 104     readline.write_history_file(histfile)