Files
poky/bitbake/lib/bb/pysh/interp.py
Chris Larson 4addbd191d Move the pysh package into the bb package
The pysh we're using is modified, and we don't want to risk it conflicting
with one from elsewhere.

(Bitbake rev: 1cbf8a9403b4b60d59bfd90a51c3e4246ab834d6)

Signed-off-by: Chris Larson <chris_larson@mentor.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2011-01-04 14:46:39 +00:00

1368 lines
49 KiB
Python

# interp.py - shell interpreter for pysh.
#
# Copyright 2007 Patrick Mezard
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.
"""Implement the shell interpreter.
Most references are made to "The Open Group Base Specifications Issue 6".
<http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html>
"""
# TODO: document the fact input streams must implement fileno() so Popen will work correctly.
# it requires non-stdin stream to be implemented as files. Still to be tested...
# DOC: pathsep is used in PATH instead of ':'. Clearly, there are path syntax issues here.
# TODO: stop command execution upon error.
# TODO: sort out the filename/io_number mess. It should be possible to use filenames only.
# TODO: review subshell implementation
# TODO: test environment cloning for non-special builtins
# TODO: set -x should not rebuild commands from tokens, assignments/redirections are lost
# TODO: unit test for variable assignment
# TODO: test error management wrt error type/utility type
# TODO: test for binary output everywhere
# BUG: debug-parsing does not pass log file to PLY. Maybe a PLY upgrade is necessary.
import base64
import cPickle as pickle
import errno
import glob
import os
import re
import subprocess
import sys
import tempfile
try:
s = set()
del s
except NameError:
from Set import Set as set
import builtin
from sherrors import *
import pyshlex
import pyshyacc
def mappend(func, *args, **kargs):
"""Like map but assume func returns a list. Returned lists are merged into
a single one.
"""
return reduce(lambda a,b: a+b, map(func, *args, **kargs), [])
class FileWrapper:
"""File object wrapper to ease debugging.
Allow mode checking and implement file duplication through a simple
reference counting scheme. Not sure the latter is really useful since
only real file descriptors can be used.
"""
def __init__(self, mode, file, close=True):
if mode not in ('r', 'w', 'a'):
raise IOError('invalid mode: %s' % mode)
self._mode = mode
self._close = close
if isinstance(file, FileWrapper):
if file._refcount[0] <= 0:
raise IOError(0, 'Error')
self._refcount = file._refcount
self._refcount[0] += 1
self._file = file._file
else:
self._refcount = [1]
self._file = file
def dup(self):
return FileWrapper(self._mode, self, self._close)
def fileno(self):
"""fileno() should be only necessary for input streams."""
return self._file.fileno()
def read(self, size=-1):
if self._mode!='r':
raise IOError(0, 'Error')
return self._file.read(size)
def readlines(self, *args, **kwargs):
return self._file.readlines(*args, **kwargs)
def write(self, s):
if self._mode not in ('w', 'a'):
raise IOError(0, 'Error')
return self._file.write(s)
def flush(self):
self._file.flush()
def close(self):
if not self._refcount:
return
assert self._refcount[0] > 0
self._refcount[0] -= 1
if self._refcount[0] == 0:
self._mode = 'c'
if self._close:
self._file.close()
self._refcount = None
def mode(self):
return self._mode
def __getattr__(self, name):
if name == 'name':
self.name = getattr(self._file, name)
return self.name
else:
raise AttributeError(name)
def __del__(self):
self.close()
def win32_open_devnull(mode):
return open('NUL', mode)
class Redirections:
"""Stores open files and their mapping to pseudo-sh file descriptor.
"""
# BUG: redirections are not handled correctly: 1>&3 2>&3 3>&4 does
# not make 1 to redirect to 4
def __init__(self, stdin=None, stdout=None, stderr=None):
self._descriptors = {}
if stdin is not None:
self._add_descriptor(0, stdin)
if stdout is not None:
self._add_descriptor(1, stdout)
if stderr is not None:
self._add_descriptor(2, stderr)
def add_here_document(self, interp, name, content, io_number=None):
if io_number is None:
io_number = 0
if name==pyshlex.unquote_wordtree(name):
content = interp.expand_here_document(('TOKEN', content))
# Write document content in a temporary file
tmp = tempfile.TemporaryFile()
try:
tmp.write(content)
tmp.flush()
tmp.seek(0)
self._add_descriptor(io_number, FileWrapper('r', tmp))
except:
tmp.close()
raise
def add(self, interp, op, filename, io_number=None):
if op not in ('<', '>', '>|', '>>', '>&'):
# TODO: add descriptor duplication and here_documents
raise RedirectionError('Unsupported redirection operator "%s"' % op)
if io_number is not None:
io_number = int(io_number)
if (op == '>&' and filename.isdigit()) or filename=='-':
# No expansion for file descriptors, quote them if you want a filename
fullname = filename
else:
if filename.startswith('/'):
# TODO: win32 kludge
if filename=='/dev/null':
fullname = 'NUL'
else:
# TODO: handle absolute pathnames, they are unlikely to exist on the
# current platform (win32 for instance).
raise NotImplementedError()
else:
fullname = interp.expand_redirection(('TOKEN', filename))
if not fullname:
raise RedirectionError('%s: ambiguous redirect' % filename)
# Build absolute path based on PWD
fullname = os.path.join(interp.get_env()['PWD'], fullname)
if op=='<':
return self._add_input_redirection(interp, fullname, io_number)
elif op in ('>', '>|'):
clobber = ('>|'==op)
return self._add_output_redirection(interp, fullname, io_number, clobber)
elif op=='>>':
return self._add_output_appending(interp, fullname, io_number)
elif op=='>&':
return self._dup_output_descriptor(fullname, io_number)
def close(self):
if self._descriptors is not None:
for desc in self._descriptors.itervalues():
desc.flush()
desc.close()
self._descriptors = None
def stdin(self):
return self._descriptors[0]
def stdout(self):
return self._descriptors[1]
def stderr(self):
return self._descriptors[2]
def clone(self):
clone = Redirections()
for desc, fileobj in self._descriptors.iteritems():
clone._descriptors[desc] = fileobj.dup()
return clone
def _add_output_redirection(self, interp, filename, io_number, clobber):
if io_number is None:
# io_number default to standard output
io_number = 1
if not clobber and interp.get_env().has_opt('-C') and os.path.isfile(filename):
# File already exist in no-clobber mode, bail out
raise RedirectionError('File "%s" already exists' % filename)
# Open and register
self._add_file_descriptor(io_number, filename, 'w')
def _add_output_appending(self, interp, filename, io_number):
if io_number is None:
io_number = 1
self._add_file_descriptor(io_number, filename, 'a')
def _add_input_redirection(self, interp, filename, io_number):
if io_number is None:
io_number = 0
self._add_file_descriptor(io_number, filename, 'r')
def _add_file_descriptor(self, io_number, filename, mode):
try:
if filename.startswith('/'):
if filename=='/dev/null':
f = win32_open_devnull(mode+'b')
else:
# TODO: handle absolute pathnames, they are unlikely to exist on the
# current platform (win32 for instance).
raise NotImplementedError('cannot open absolute path %s' % repr(filename))
else:
f = file(filename, mode+'b')
except IOError, e:
raise RedirectionError(str(e))
wrapper = None
try:
wrapper = FileWrapper(mode, f)
f = None
self._add_descriptor(io_number, wrapper)
except:
if f: f.close()
if wrapper: wrapper.close()
raise
def _dup_output_descriptor(self, source_fd, dest_fd):
if source_fd is None:
source_fd = 1
self._dup_file_descriptor(source_fd, dest_fd, 'w')
def _dup_file_descriptor(self, source_fd, dest_fd, mode):
source_fd = int(source_fd)
if source_fd not in self._descriptors:
raise RedirectionError('"%s" is not a valid file descriptor' % str(source_fd))
source = self._descriptors[source_fd]
if source.mode()!=mode:
raise RedirectionError('Descriptor %s cannot be duplicated in mode "%s"' % (str(source), mode))
if dest_fd=='-':
# Close the source descriptor
del self._descriptors[source_fd]
source.close()
else:
dest_fd = int(dest_fd)
if dest_fd not in self._descriptors:
raise RedirectionError('Cannot replace file descriptor %s' % str(dest_fd))
dest = self._descriptors[dest_fd]
if dest.mode()!=mode:
raise RedirectionError('Descriptor %s cannot be cannot be redirected in mode "%s"' % (str(dest), mode))
self._descriptors[dest_fd] = source.dup()
dest.close()
def _add_descriptor(self, io_number, file):
io_number = int(io_number)
if io_number in self._descriptors:
# Close the current descriptor
d = self._descriptors[io_number]
del self._descriptors[io_number]
d.close()
self._descriptors[io_number] = file
def __str__(self):
names = [('%d=%r' % (k, getattr(v, 'name', None))) for k,v
in self._descriptors.iteritems()]
names = ','.join(names)
return 'Redirections(%s)' % names
def __del__(self):
self.close()
def cygwin_to_windows_path(path):
"""Turn /cygdrive/c/foo into c:/foo, or return path if it
is not a cygwin path.
"""
if not path.startswith('/cygdrive/'):
return path
path = path[len('/cygdrive/'):]
path = path[:1] + ':' + path[1:]
return path
def win32_to_unix_path(path):
if path is not None:
path = path.replace('\\', '/')
return path
_RE_SHEBANG = re.compile(r'^\#!\s?([^\s]+)(?:\s([^\s]+))?')
_SHEBANG_CMDS = {
'/usr/bin/env': 'env',
'/bin/sh': 'pysh',
'python': 'python',
}
def resolve_shebang(path, ignoreshell=False):
"""Return a list of arguments as shebang interpreter call or an empty list
if path does not refer to an executable script.
See <http://www.opengroup.org/austin/docs/austin_51r2.txt>.
ignoreshell - set to True to ignore sh shebangs. Return an empty list instead.
"""
try:
f = file(path)
try:
# At most 80 characters in the first line
header = f.read(80).splitlines()[0]
finally:
f.close()
m = _RE_SHEBANG.search(header)
if not m:
return []
cmd, arg = m.group(1,2)
if os.path.isfile(cmd):
# Keep this one, the hg script for instance contains a weird windows
# shebang referencing the current python install.
cmdfile = os.path.basename(cmd).lower()
if cmdfile == 'python.exe':
cmd = 'python'
pass
elif cmd not in _SHEBANG_CMDS:
raise CommandNotFound('Unknown interpreter "%s" referenced in '\
'shebang' % header)
cmd = _SHEBANG_CMDS.get(cmd)
if cmd is None or (ignoreshell and cmd == 'pysh'):
return []
if arg is None:
return [cmd, win32_to_unix_path(path)]
return [cmd, arg, win32_to_unix_path(path)]
except IOError, e:
if e.errno!=errno.ENOENT and \
(e.errno!=errno.EPERM and not os.path.isdir(path)): # Opening a directory raises EPERM
raise
return []
def win32_find_in_path(name, path):
if isinstance(path, str):
path = path.split(os.pathsep)
exts = os.environ.get('PATHEXT', '').lower().split(os.pathsep)
for p in path:
p_name = os.path.join(p, name)
prefix = resolve_shebang(p_name)
if prefix:
return prefix
for ext in exts:
p_name_ext = p_name + ext
if os.path.exists(p_name_ext):
return [win32_to_unix_path(p_name_ext)]
return []
class Traps(dict):
def __setitem__(self, key, value):
if key not in ('EXIT',):
raise NotImplementedError()
super(Traps, self).__setitem__(key, value)
# IFS white spaces character class
_IFS_WHITESPACES = (' ', '\t', '\n')
class Environment:
"""Environment holds environment variables, export table, function
definitions and whatever is defined in 2.12 "Shell Execution Environment",
redirection excepted.
"""
def __init__(self, pwd):
self._opt = set() #Shell options
self._functions = {}
self._env = {'?': '0', '#': '0'}
self._exported = set([
'HOME', 'IFS', 'PATH'
])
# Set environment vars with side-effects
self._ifs_ws = None # Set of IFS whitespace characters
self._ifs_re = None # Regular expression used to split between words using IFS classes
self['IFS'] = ''.join(_IFS_WHITESPACES) #Default environment values
self['PWD'] = pwd
self.traps = Traps()
def clone(self, subshell=False):
env = Environment(self['PWD'])
env._opt = set(self._opt)
for k,v in self.get_variables().iteritems():
if k in self._exported:
env.export(k,v)
elif subshell:
env[k] = v
if subshell:
env._functions = dict(self._functions)
return env
def __getitem__(self, key):
if key in ('@', '*', '-', '$'):
raise NotImplementedError('%s is not implemented' % repr(key))
return self._env[key]
def get(self, key, defval=None):
try:
return self[key]
except KeyError:
return defval
def __setitem__(self, key, value):
if key=='IFS':
# Update the whitespace/non-whitespace classes
self._update_ifs(value)
elif key=='PWD':
pwd = os.path.abspath(value)
if not os.path.isdir(pwd):
raise VarAssignmentError('Invalid directory %s' % value)
value = pwd
elif key in ('?', '!'):
value = str(int(value))
self._env[key] = value
def __delitem__(self, key):
if key in ('IFS', 'PWD', '?'):
raise VarAssignmentError('%s cannot be unset' % key)
del self._env[key]
def __contains__(self, item):
return item in self._env
def set_positional_args(self, args):
"""Set the content of 'args' as positional argument from 1 to len(args).
Return previous argument as a list of strings.
"""
# Save and remove previous arguments
prevargs = []
for i in xrange(int(self._env['#'])):
i = str(i+1)
prevargs.append(self._env[i])
del self._env[i]
self._env['#'] = '0'
#Set new ones
for i,arg in enumerate(args):
self._env[str(i+1)] = str(arg)
self._env['#'] = str(len(args))
return prevargs
def get_positional_args(self):
return [self._env[str(i+1)] for i in xrange(int(self._env['#']))]
def get_variables(self):
return dict(self._env)
def export(self, key, value=None):
if value is not None:
self[key] = value
self._exported.add(key)
def get_exported(self):
return [(k,self._env.get(k)) for k in self._exported]
def split_fields(self, word):
if not self._ifs_ws or not word:
return [word]
return re.split(self._ifs_re, word)
def _update_ifs(self, value):
"""Update the split_fields related variables when IFS character set is
changed.
"""
# TODO: handle NULL IFS
# Separate characters in whitespace and non-whitespace
chars = set(value)
ws = [c for c in chars if c in _IFS_WHITESPACES]
nws = [c for c in chars if c not in _IFS_WHITESPACES]
# Keep whitespaces in a string for left and right stripping
self._ifs_ws = ''.join(ws)
# Build a regexp to split fields
trailing = '[' + ''.join([re.escape(c) for c in ws]) + ']'
if nws:
# First, the single non-whitespace occurence.
nws = '[' + ''.join([re.escape(c) for c in nws]) + ']'
nws = '(?:' + trailing + '*' + nws + trailing + '*' + '|' + trailing + '+)'
else:
# Then mix all parts with quantifiers
nws = trailing + '+'
self._ifs_re = re.compile(nws)
def has_opt(self, opt, val=None):
return (opt, val) in self._opt
def set_opt(self, opt, val=None):
self._opt.add((opt, val))
def find_in_path(self, name, pwd=False):
path = self._env.get('PATH', '').split(os.pathsep)
if pwd:
path[:0] = [self['PWD']]
if os.name == 'nt':
return win32_find_in_path(name, self._env.get('PATH', ''))
else:
raise NotImplementedError()
def define_function(self, name, body):
if not is_name(name):
raise ShellSyntaxError('%s is not a valid function name' % repr(name))
self._functions[name] = body
def remove_function(self, name):
del self._functions[name]
def is_function(self, name):
return name in self._functions
def get_function(self, name):
return self._functions.get(name)
name_charset = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_'
name_charset = dict(zip(name_charset,name_charset))
def match_name(s):
"""Return the length in characters of the longest prefix made of name
allowed characters in s.
"""
for i,c in enumerate(s):
if c not in name_charset:
return s[:i]
return s
def is_name(s):
return len([c for c in s if c not in name_charset])<=0
def is_special_param(c):
return len(c)==1 and c in ('@','*','#','?','-','$','!','0')
def utility_not_implemented(name, *args, **kwargs):
raise NotImplementedError('%s utility is not implemented' % name)
class Utility:
"""Define utilities properties:
func -- utility callable. See builtin module for utility samples.
is_special -- see XCU 2.8.
"""
def __init__(self, func, is_special=0):
self.func = func
self.is_special = bool(is_special)
def encodeargs(args):
def encodearg(s):
lines = base64.encodestring(s)
lines = [l.splitlines()[0] for l in lines]
return ''.join(lines)
s = pickle.dumps(args)
return encodearg(s)
def decodeargs(s):
s = base64.decodestring(s)
return pickle.loads(s)
class GlobError(Exception):
pass
class Options:
def __init__(self):
# True if Mercurial operates with binary streams
self.hgbinary = True
class Interpreter:
# Implementation is very basic: the execute() method just makes a DFS on the
# AST and execute nodes one by one. Nodes are tuple (name,obj) where name
# is a string identifier and obj the AST element returned by the parser.
#
# Handler are named after the node identifiers.
# TODO: check node names and remove the switch in execute with some
# dynamic getattr() call to find node handlers.
"""Shell interpreter.
The following debugging flags can be passed:
debug-parsing - enable PLY debugging.
debug-tree - print the generated AST.
debug-cmd - trace command execution before word expansion, plus exit status.
debug-utility - trace utility execution.
"""
# List supported commands.
COMMANDS = {
'cat': Utility(builtin.utility_cat,),
'cd': Utility(builtin.utility_cd,),
':': Utility(builtin.utility_colon,),
'echo': Utility(builtin.utility_echo),
'env': Utility(builtin.utility_env),
'exit': Utility(builtin.utility_exit),
'export': Utility(builtin.builtin_export, is_special=1),
'egrep': Utility(builtin.utility_egrep),
'fgrep': Utility(builtin.utility_fgrep),
'gunzip': Utility(builtin.utility_gunzip),
'kill': Utility(builtin.utility_kill),
'mkdir': Utility(builtin.utility_mkdir),
'netstat': Utility(builtin.utility_netstat),
'printf': Utility(builtin.utility_printf),
'pwd': Utility(builtin.utility_pwd),
'return': Utility(builtin.builtin_return, is_special=1),
'sed': Utility(builtin.utility_sed,),
'set': Utility(builtin.builtin_set,),
'shift': Utility(builtin.builtin_shift,),
'sleep': Utility(builtin.utility_sleep,),
'sort': Utility(builtin.utility_sort,),
'trap': Utility(builtin.builtin_trap, is_special=1),
'true': Utility(builtin.utility_true),
'unset': Utility(builtin.builtin_unset, is_special=1),
'wait': Utility(builtin.builtin_wait, is_special=1),
}
def __init__(self, pwd, debugflags = [], env=None, redirs=None, stdin=None,
stdout=None, stderr=None, opts=Options()):
self._env = env
if self._env is None:
self._env = Environment(pwd)
self._children = {}
self._redirs = redirs
self._close_redirs = False
if self._redirs is None:
if stdin is None:
stdin = sys.stdin
if stdout is None:
stdout = sys.stdout
if stderr is None:
stderr = sys.stderr
stdin = FileWrapper('r', stdin, False)
stdout = FileWrapper('w', stdout, False)
stderr = FileWrapper('w', stderr, False)
self._redirs = Redirections(stdin, stdout, stderr)
self._close_redirs = True
self._debugflags = list(debugflags)
self._logfile = sys.stderr
self._options = opts
def close(self):
"""Must be called when the interpreter is no longer used."""
script = self._env.traps.get('EXIT')
if script:
try:
self.execute_script(script=script)
except:
pass
if self._redirs is not None and self._close_redirs:
self._redirs.close()
self._redirs = None
def log(self, s):
self._logfile.write(s)
self._logfile.flush()
def __getitem__(self, key):
return self._env[key]
def __setitem__(self, key, value):
self._env[key] = value
def options(self):
return self._options
def redirect(self, redirs, ios):
def add_redir(io):
if isinstance(io, pyshyacc.IORedirect):
redirs.add(self, io.op, io.filename, io.io_number)
else:
redirs.add_here_document(self, io.name, io.content, io.io_number)
map(add_redir, ios)
return redirs
def execute_script(self, script=None, ast=None, sourced=False,
scriptpath=None):
"""If script is not None, parse the input. Otherwise takes the supplied
AST. Then execute the AST.
Return the script exit status.
"""
try:
if scriptpath is not None:
self._env['0'] = os.path.abspath(scriptpath)
if script is not None:
debug_parsing = ('debug-parsing' in self._debugflags)
cmds, script = pyshyacc.parse(script, True, debug_parsing)
if 'debug-tree' in self._debugflags:
pyshyacc.print_commands(cmds, self._logfile)
self._logfile.flush()
else:
cmds, script = ast, ''
status = 0
for cmd in cmds:
try:
status = self.execute(cmd)
except ExitSignal, e:
if sourced:
raise
status = int(e.args[0])
return status
except ShellError:
self._env['?'] = 1
raise
if 'debug-utility' in self._debugflags or 'debug-cmd' in self._debugflags:
self.log('returncode ' + str(status)+ '\n')
return status
except CommandNotFound, e:
print >>self._redirs.stderr, str(e)
self._redirs.stderr.flush()
# Command not found by non-interactive shell
# return 127
raise
except RedirectionError, e:
# TODO: should be handled depending on the utility status
print >>self._redirs.stderr, str(e)
self._redirs.stderr.flush()
# Command not found by non-interactive shell
# return 127
raise
def dotcommand(self, env, args):
if len(args) < 1:
raise ShellError('. expects at least one argument')
path = args[0]
if '/' not in path:
found = env.find_in_path(args[0], True)
if found:
path = found[0]
script = file(path).read()
return self.execute_script(script=script, sourced=True)
def execute(self, token, redirs=None):
"""Execute and AST subtree with supplied redirections overriding default
interpreter ones.
Return the exit status.
"""
if not token:
return 0
if redirs is None:
redirs = self._redirs
if isinstance(token, list):
# Commands sequence
res = 0
for t in token:
res = self.execute(t, redirs)
return res
type, value = token
status = 0
if type=='simple_command':
redirs_copy = redirs.clone()
try:
# TODO: define and handle command return values
# TODO: implement set -e
status = self._execute_simple_command(value, redirs_copy)
finally:
redirs_copy.close()
elif type=='pipeline':
status = self._execute_pipeline(value, redirs)
elif type=='and_or':
status = self._execute_and_or(value, redirs)
elif type=='for_clause':
status = self._execute_for_clause(value, redirs)
elif type=='while_clause':
status = self._execute_while_clause(value, redirs)
elif type=='function_definition':
status = self._execute_function_definition(value, redirs)
elif type=='brace_group':
status = self._execute_brace_group(value, redirs)
elif type=='if_clause':
status = self._execute_if_clause(value, redirs)
elif type=='subshell':
status = self.subshell(ast=value.cmds, redirs=redirs)
elif type=='async':
status = self._asynclist(value)
elif type=='redirect_list':
redirs_copy = self.redirect(redirs.clone(), value.redirs)
try:
status = self.execute(value.cmd, redirs_copy)
finally:
redirs_copy.close()
else:
raise NotImplementedError('Unsupported token type ' + type)
if status < 0:
status = 255
return status
def _execute_if_clause(self, if_clause, redirs):
cond_status = self.execute(if_clause.cond, redirs)
if cond_status==0:
return self.execute(if_clause.if_cmds, redirs)
else:
return self.execute(if_clause.else_cmds, redirs)
def _execute_brace_group(self, group, redirs):
status = 0
for cmd in group.cmds:
status = self.execute(cmd, redirs)
return status
def _execute_function_definition(self, fundef, redirs):
self._env.define_function(fundef.name, fundef.body)
return 0
def _execute_while_clause(self, while_clause, redirs):
status = 0
while 1:
cond_status = 0
for cond in while_clause.condition:
cond_status = self.execute(cond, redirs)
if cond_status:
break
for cmd in while_clause.cmds:
status = self.execute(cmd, redirs)
return status
def _execute_for_clause(self, for_clause, redirs):
if not is_name(for_clause.name):
raise ShellSyntaxError('%s is not a valid name' % repr(for_clause.name))
items = mappend(self.expand_token, for_clause.items)
status = 0
for item in items:
self._env[for_clause.name] = item
for cmd in for_clause.cmds:
status = self.execute(cmd, redirs)
return status
def _execute_and_or(self, or_and, redirs):
res = self.execute(or_and.left, redirs)
if (or_and.op=='&&' and res==0) or (or_and.op!='&&' and res!=0):
res = self.execute(or_and.right, redirs)
return res
def _execute_pipeline(self, pipeline, redirs):
if len(pipeline.commands)==1:
status = self.execute(pipeline.commands[0], redirs)
else:
# Execute all commands one after the other
status = 0
inpath, outpath = None, None
try:
# Commands inputs and outputs cannot really be plugged as done
# by a real shell. Run commands sequentially and chain their
# input/output throught temporary files.
tmpfd, inpath = tempfile.mkstemp()
os.close(tmpfd)
tmpfd, outpath = tempfile.mkstemp()
os.close(tmpfd)
inpath = win32_to_unix_path(inpath)
outpath = win32_to_unix_path(outpath)
for i, cmd in enumerate(pipeline.commands):
call_redirs = redirs.clone()
try:
if i!=0:
call_redirs.add(self, '<', inpath)
if i!=len(pipeline.commands)-1:
call_redirs.add(self, '>', outpath)
status = self.execute(cmd, call_redirs)
# Chain inputs/outputs
inpath, outpath = outpath, inpath
finally:
call_redirs.close()
finally:
if inpath: os.remove(inpath)
if outpath: os.remove(outpath)
if pipeline.reverse_status:
status = int(not status)
self._env['?'] = status
return status
def _execute_function(self, name, args, interp, env, stdin, stdout, stderr, *others):
assert interp is self
func = env.get_function(name)
#Set positional parameters
prevargs = None
try:
prevargs = env.set_positional_args(args)
try:
redirs = Redirections(stdin.dup(), stdout.dup(), stderr.dup())
try:
status = self.execute(func, redirs)
finally:
redirs.close()
except ReturnSignal, e:
status = int(e.args[0])
env['?'] = status
return status
finally:
#Reset positional parameters
if prevargs is not None:
env.set_positional_args(prevargs)
def _execute_simple_command(self, token, redirs):
"""Can raise ReturnSignal when return builtin is called, ExitSignal when
exit is called, and other shell exceptions upon builtin failures.
"""
debug_command = 'debug-cmd' in self._debugflags
if debug_command:
self.log('word' + repr(token.words) + '\n')
self.log('assigns' + repr(token.assigns) + '\n')
self.log('redirs' + repr(token.redirs) + '\n')
is_special = None
env = self._env
try:
# Word expansion
args = []
for word in token.words:
args += self.expand_token(word)
if is_special is None and args:
is_special = env.is_function(args[0]) or \
(args[0] in self.COMMANDS and self.COMMANDS[args[0]].is_special)
if debug_command:
self.log('_execute_simple_command' + str(args) + '\n')
if not args:
# Redirections happen is a subshell
redirs = redirs.clone()
elif not is_special:
env = self._env.clone()
# Redirections
self.redirect(redirs, token.redirs)
# Variables assignments
res = 0
for type,(k,v) in token.assigns:
status, expanded = self.expand_variable((k,v))
if status is not None:
res = status
if args:
env.export(k, expanded)
else:
env[k] = expanded
if args and args[0] in ('.', 'source'):
res = self.dotcommand(env, args[1:])
elif args:
if args[0] in self.COMMANDS:
command = self.COMMANDS[args[0]]
elif env.is_function(args[0]):
command = Utility(self._execute_function, is_special=True)
else:
if not '/' in args[0].replace('\\', '/'):
cmd = env.find_in_path(args[0])
if not cmd:
# TODO: test error code on unknown command => 127
raise CommandNotFound('Unknown command: "%s"' % args[0])
else:
# Handle commands like '/cygdrive/c/foo.bat'
cmd = cygwin_to_windows_path(args[0])
if not os.path.exists(cmd):
raise CommandNotFound('%s: No such file or directory' % args[0])
shebang = resolve_shebang(cmd)
if shebang:
cmd = shebang
else:
cmd = [cmd]
args[0:1] = cmd
command = Utility(builtin.run_command)
# Command execution
if 'debug-cmd' in self._debugflags:
self.log('redirections ' + str(redirs) + '\n')
res = command.func(args[0], args[1:], self, env,
redirs.stdin(), redirs.stdout(),
redirs.stderr(), self._debugflags)
if self._env.has_opt('-x'):
# Trace command execution in shell environment
# BUG: would be hard to reproduce a real shell behaviour since
# the AST is not annotated with source lines/tokens.
self._redirs.stdout().write(' '.join(args))
except ReturnSignal:
raise
except ShellError, e:
if is_special or isinstance(e, (ExitSignal,
ShellSyntaxError, ExpansionError)):
raise e
self._redirs.stderr().write(str(e)+'\n')
return 1
return res
def expand_token(self, word):
"""Expand a word as specified in [2.6 Word Expansions]. Return the list
of expanded words.
"""
status, wtrees = self._expand_word(word)
return map(pyshlex.wordtree_as_string, wtrees)
def expand_variable(self, word):
"""Return a status code (or None if no command expansion occurred)
and a single word.
"""
status, wtrees = self._expand_word(word, pathname=False, split=False)
words = map(pyshlex.wordtree_as_string, wtrees)
assert len(words)==1
return status, words[0]
def expand_here_document(self, word):
"""Return the expanded document as a single word. The here document is
assumed to be unquoted.
"""
status, wtrees = self._expand_word(word, pathname=False,
split=False, here_document=True)
words = map(pyshlex.wordtree_as_string, wtrees)
assert len(words)==1
return words[0]
def expand_redirection(self, word):
"""Return a single word."""
return self.expand_variable(word)[1]
def get_env(self):
return self._env
def _expand_word(self, token, pathname=True, split=True, here_document=False):
wtree = pyshlex.make_wordtree(token[1], here_document=here_document)
# TODO: implement tilde expansion
def expand(wtree):
"""Return a pseudo wordtree: the tree or its subelements can be empty
lists when no value result from the expansion.
"""
status = None
for part in wtree:
if not isinstance(part, list):
continue
if part[0]in ("'", '\\'):
continue
elif part[0] in ('`', '$('):
status, result = self._expand_command(part)
part[:] = result
elif part[0] in ('$', '${'):
part[:] = self._expand_parameter(part, wtree[0]=='"', split)
elif part[0] in ('', '"'):
status, result = expand(part)
part[:] = result
else:
raise NotImplementedError('%s expansion is not implemented'
% part[0])
# [] is returned when an expansion result in no-field,
# like an empty $@
wtree = [p for p in wtree if p != []]
if len(wtree) < 3:
return status, []
return status, wtree
status, wtree = expand(wtree)
if len(wtree) == 0:
return status, wtree
wtree = pyshlex.normalize_wordtree(wtree)
if split:
wtrees = self._split_fields(wtree)
else:
wtrees = [wtree]
if pathname:
wtrees = mappend(self._expand_pathname, wtrees)
wtrees = map(self._remove_quotes, wtrees)
return status, wtrees
def _expand_command(self, wtree):
# BUG: there is something to do with backslashes and quoted
# characters here
command = pyshlex.wordtree_as_string(wtree[1:-1])
status, output = self.subshell_output(command)
return status, ['', output, '']
def _expand_parameter(self, wtree, quoted=False, split=False):
"""Return a valid wtree or an empty list when no parameter results."""
# Get the parameter name
# TODO: implement weird expansion rules with ':'
name = pyshlex.wordtree_as_string(wtree[1:-1])
if not is_name(name) and not is_special_param(name):
raise ExpansionError('Bad substitution "%s"' % name)
# TODO: implement special parameters
if name in ('@', '*'):
args = self._env.get_positional_args()
if len(args) == 0:
return []
if len(args)<2:
return ['', ''.join(args), '']
sep = self._env.get('IFS', '')[:1]
if split and quoted and name=='@':
# Introduce a new token to tell the caller that these parameters
# cause a split as specified in 2.5.2
return ['@'] + args + ['']
else:
return ['', sep.join(args), '']
return ['', self._env.get(name, ''), '']
def _split_fields(self, wtree):
def is_empty(split):
return split==['', '', '']
def split_positional(quoted):
# Return a list of wtree split according positional parameters rules.
# All remaining '@' groups are removed.
assert quoted[0]=='"'
splits = [[]]
for part in quoted:
if not isinstance(part, list) or part[0]!='@':
splits[-1].append(part)
else:
# Empty or single argument list were dealt with already
assert len(part)>3
# First argument must join with the beginning part of the original word
splits[-1].append(part[1])
# Create double-quotes expressions for every argument after the first
for arg in part[2:-1]:
splits[-1].append('"')
splits.append(['"', arg])
return splits
# At this point, all expansions but pathnames have occured. Only quoted
# and positional sequences remain. Thus, all candidates for field splitting
# are in the tree root, or are positional splits ('@') and lie in root
# children.
if not wtree or wtree[0] not in ('', '"'):
# The whole token is quoted or empty, nothing to split
return [wtree]
if wtree[0]=='"':
wtree = ['', wtree, '']
result = [['', '']]
for part in wtree[1:-1]:
if isinstance(part, list):
if part[0]=='"':
splits = split_positional(part)
if len(splits)<=1:
result[-1] += [part, '']
else:
# Terminate the current split
result[-1] += [splits[0], '']
result += splits[1:-1]
# Create a new split
result += [['', splits[-1], '']]
else:
result[-1] += [part, '']
else:
splits = self._env.split_fields(part)
if len(splits)<=1:
# No split
result[-1][-1] += part
else:
# Terminate the current resulting part and create a new one
result[-1][-1] += splits[0]
result[-1].append('')
result += [['', r, ''] for r in splits[1:-1]]
result += [['', splits[-1]]]
result[-1].append('')
# Leading and trailing empty groups come from leading/trailing blanks
if result and is_empty(result[-1]):
result[-1:] = []
if result and is_empty(result[0]):
result[:1] = []
return result
def _expand_pathname(self, wtree):
"""See [2.6.6 Pathname Expansion]."""
if self._env.has_opt('-f'):
return [wtree]
# All expansions have been performed, only quoted sequences should remain
# in the tree. Generate the pattern by folding the tree, escaping special
# characters when appear quoted
special_chars = '*?[]'
def make_pattern(wtree):
subpattern = []
for part in wtree[1:-1]:
if isinstance(part, list):
part = make_pattern(part)
elif wtree[0]!='':
for c in part:
# Meta-characters cannot be quoted
if c in special_chars:
raise GlobError()
subpattern.append(part)
return ''.join(subpattern)
def pwd_glob(pattern):
cwd = os.getcwd()
os.chdir(self._env['PWD'])
try:
return glob.glob(pattern)
finally:
os.chdir(cwd)
#TODO: check working directory issues here wrt relative patterns
try:
pattern = make_pattern(wtree)
paths = pwd_glob(pattern)
except GlobError:
# BUG: Meta-characters were found in quoted sequences. The should
# have been used literally but this is unsupported in current glob module.
# Instead we consider the whole tree must be used literally and
# therefore there is no point in globbing. This is wrong when meta
# characters are mixed with quoted meta in the same pattern like:
# < foo*"py*" >
paths = []
if not paths:
return [wtree]
return [['', path, ''] for path in paths]
def _remove_quotes(self, wtree):
"""See [2.6.7 Quote Removal]."""
def unquote(wtree):
unquoted = []
for part in wtree[1:-1]:
if isinstance(part, list):
part = unquote(part)
unquoted.append(part)
return ''.join(unquoted)
return ['', unquote(wtree), '']
def subshell(self, script=None, ast=None, redirs=None):
"""Execute the script or AST in a subshell, with inherited redirections
if redirs is not None.
"""
if redirs:
sub_redirs = redirs
else:
sub_redirs = redirs.clone()
subshell = None
try:
subshell = Interpreter(None, self._debugflags, self._env.clone(True),
sub_redirs, opts=self._options)
return subshell.execute_script(script, ast)
finally:
if not redirs: sub_redirs.close()
if subshell: subshell.close()
def subshell_output(self, script):
"""Execute the script in a subshell and return the captured output."""
# Create temporary file to capture subshell output
tmpfd, tmppath = tempfile.mkstemp()
try:
tmpfile = os.fdopen(tmpfd, 'wb')
stdout = FileWrapper('w', tmpfile)
redirs = Redirections(self._redirs.stdin().dup(),
stdout,
self._redirs.stderr().dup())
try:
status = self.subshell(script=script, redirs=redirs)
finally:
redirs.close()
redirs = None
# Extract subshell standard output
tmpfile = open(tmppath, 'rb')
try:
output = tmpfile.read()
return status, output.rstrip('\n')
finally:
tmpfile.close()
finally:
os.remove(tmppath)
def _asynclist(self, cmd):
args = (self._env.get_variables(), cmd)
arg = encodeargs(args)
assert len(args) < 30*1024
cmd = ['pysh.bat', '--ast', '-c', arg]
p = subprocess.Popen(cmd, cwd=self._env['PWD'])
self._children[p.pid] = p
self._env['!'] = p.pid
return 0
def wait(self, pids=None):
if not pids:
pids = self._children.keys()
status = 127
for pid in pids:
if pid not in self._children:
continue
p = self._children.pop(pid)
status = p.wait()
return status