scripts/oepydevshell-internal.py

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