def testShellFuncExecution(self):
ex = cmd_exec_test.InitExecutor()
func_node = ast.FuncDef()
c1 = ast.CompoundWord()
t1 = ast.token(Id.Lit_Chars, 'f1')
c1.parts.append(ast.LiteralPart(t1))
c2 = ast.CompoundWord()
t2 = ast.token(Id.Lit_Chars, 'f2')
c2.parts.append(ast.LiteralPart(t2))
a = ast.ArrayLiteralPart()
a.words = [c1, c2]
w = ast.CompoundWord()
w.parts.append(a)
# Set global COMPREPLY=(f1 f2)
pair = ast.assign_pair(ast.LhsName('COMPREPLY'), assign_op_e.Equal, w)
pair.spids.append(0) # dummy
pairs = [pair]
body_node = ast.Assignment(Id.Assign_None, [], pairs)
func_node.name = 'myfunc'
func_node.body = body_node
a = completion.ShellFuncAction(ex, func_node)
matches = list(a.Matches([], 0, 'f'))
self.assertEqual(['f1 ', 'f2 '], matches)
def testPipeline2(self):
Banner('ls | cut -d . -f 1 | head')
p = process.Pipeline()
p.Add(_ExtProc(['ls']))
p.Add(_ExtProc(['cut', '-d', '.', '-f', '1']))
p.Add(_ExtProc(['head']))
print(p.Run(_WAITER))
ex = InitExecutor()
# Simulating subshell for each command
w1 = ast.CompoundWord()
w1.parts.append(ast.LiteralPart(ast.token(Id.Lit_Chars, 'ls')))
node1 = ast.SimpleCommand()
node1.words = [w1]
w2 = ast.CompoundWord()
w2.parts.append(ast.LiteralPart(ast.token(Id.Lit_Chars, 'head')))
node2 = ast.SimpleCommand()
node2.words = [w2]
w3 = ast.CompoundWord()
w3.parts.append(ast.LiteralPart(ast.token(Id.Lit_Chars, 'sort')))
w4 = ast.CompoundWord()
w4.parts.append(ast.LiteralPart(ast.token(Id.Lit_Chars, '--reverse')))
node3 = ast.SimpleCommand()
node3.words = [w3, w4]
p = process.Pipeline()
p.Add(Process(process.SubProgramThunk(ex, node1)))
p.Add(Process(process.SubProgramThunk(ex, node2)))
p.Add(Process(process.SubProgramThunk(ex, node3)))
print(p.Run(_WAITER))
def _ReadExtGlobPart(self):
"""
Grammar:
Item = CompoundWord | EPSILON # important: @(foo|) is allowed
LEFT = '@(' | '*(' | '+(' | '?(' | '!('
RIGHT = ')'
ExtGlob = LEFT (Item '|')* Item RIGHT # ITEM may be empty
CompoundWord includes ExtGlobPart
"""
left_token = self.cur_token
arms = []
part = ast.ExtGlobPart(left_token, arms) # return value
part.spids.append(left_token.span_id)
self.lexer.PushHint(Id.Op_RParen, Id.Right_ExtGlob)
self._Next(lex_mode_e.EXTGLOB) # advance past LEFT
read_word = False # did we just a read a word? To handle @(||).
while True:
self._Peek()
#log('t %r', self.cur_token)
if self.token_type == Id.Right_ExtGlob:
if not read_word:
arms.append(ast.CompoundWord())
part.spids.append(self.cur_token.span_id)
break
elif self.token_type == Id.Op_Pipe:
if not read_word:
arms.append(ast.CompoundWord())
read_word = False
self._Next(lex_mode_e.EXTGLOB)
# lex mode EXTGLOB should only produce these 4 kinds of tokens
elif self.token_kind in (Kind.Lit, Kind.Left, Kind.VSub,
Kind.ExtGlob):
w = self._ReadCompoundWord(lex_mode=lex_mode_e.EXTGLOB)
arms.append(w)
read_word = True
elif self.token_kind == Kind.Eof:
self.AddErrorContext(
'Unexpected EOF reading extended glob that began here',
token=left_token)
return None
else:
raise AssertionError('Unexpected token %r' % self.cur_token)
return part
def testVarOps(self):
ev = InitEvaluator() # initializes x=xxx and y=yyy
unset_sub = ast.BracedVarSub(ast.token(Id.VSub_Name, 'unset'))
part_vals = []
ev._EvalWordPart(unset_sub, part_vals)
print(part_vals)
set_sub = ast.BracedVarSub(ast.token(Id.VSub_Name, 'x'))
part_vals = []
ev._EvalWordPart(set_sub, part_vals)
print(part_vals)
# Now add some ops
part = ast.LiteralPart(ast.token(Id.Lit_Chars, 'default'))
arg_word = ast.CompoundWord([part])
test_op = ast.StringUnary(Id.VTest_ColonHyphen, arg_word)
unset_sub.suffix_op = test_op
set_sub.suffix_op = test_op
part_vals = []
ev._EvalWordPart(unset_sub, part_vals)
print(part_vals)
part_vals = []
ev._EvalWordPart(set_sub, part_vals)
print(part_vals)
def EvalPrompt(self, val):
"""Perform the two evaluations that bash does. Used by $PS1 and ${x@P}."""
if val.tag != value_e.Str:
return DEFAULT_PS1 # no evaluation necessary
try:
tokens = self.tokens_cache[val.s]
except KeyError:
tokens = match.PS1_LEXER.Tokens(val.s)
self.tokens_cache[val.s] = tokens
# First replacements. TODO: Should we cache this too?
ps1_str = self._ReplaceBackslashCodes(tokens)
# The prompt is often constant, so we can avoid parsing it.
# NOTE: This is copied from the PS4 logic in Tracer.
try:
ps1_word = self.parse_cache[ps1_str]
except KeyError:
w_parser = self.parse_ctx.MakeWordParserForPlugin(
ps1_str, self.arena)
try:
ps1_word = w_parser.ReadPS()
except Exception as e:
error_str = '<ERROR: cannot parse PS1>'
t = ast.token(Id.Lit_Chars, error_str, const.NO_INTEGER)
ps1_word = ast.CompoundWord([ast.LiteralPart(t)])
self.parse_cache[ps1_str] = ps1_word
# e.g. "${debian_chroot}\u" -> '\u'
val2 = self.ex.word_ev.EvalWordToString(ps1_word)
return val2.s
def EvalPrompt(self, val):
"""Perform the two evaluations that bash does. Used by $PS1 and ${x@P}."""
if val.tag != value_e.Str:
return DEFAULT_PS1 # no evaluation necessary
# Parse backslash escapes (cached)
try:
tokens = self.tokens_cache[val.s]
except KeyError:
tokens = list(match.PS1_LEXER.Tokens(val.s))
self.tokens_cache[val.s] = tokens
# Replace values.
ps1_str = self._ReplaceBackslashCodes(tokens)
# Parse it like a double-quoted word (cached).
# NOTE: This is copied from the PS4 logic in Tracer.
try:
ps1_word = self.parse_cache[ps1_str]
except KeyError:
w_parser = self.parse_ctx.MakeWordParserForPlugin(
ps1_str, self.arena)
try:
ps1_word = w_parser.ReadPS()
except Exception as e:
error_str = '<ERROR: cannot parse PS1>'
t = ast.token(Id.Lit_Chars, error_str, const.NO_INTEGER)
ps1_word = ast.CompoundWord([ast.LiteralPart(t)])
self.parse_cache[ps1_str] = ps1_word
# Evaluate, e.g. "${debian_chroot}\u" -> '\u'
val2 = self.ex.word_ev.EvalWordToString(ps1_word)
return val2.s
def ReadPS(self):
"""For $PS1, $PS4, etc.
This is just like reading a here doc line. "\n" is allowed, as well as the
typical substitutions ${x} $(echo hi) $((1 + 2)).
"""
w = ast.CompoundWord()
self._ReadLikeDQ(None, w.parts)
return w
def _MaybeReadHereDocs(self):
for h in self.pending_here_docs:
lines = []
#log('HERE %r' % h.here_end)
while True:
# If op is <<-, strip off all leading tabs (NOT spaces).
# (in C++, just bump the start?)
line_id, line = self.line_reader.GetLine()
#print("LINE %r %r" % (line, h.here_end))
if not line: # EOF
# An unterminated here doc is just a warning in bash. We make it
# fatal because we want to be strict, and because it causes problems
# reporting other errors.
# Attribute it to the << in <<EOF for now.
self.AddErrorContext('Unterminated here doc', span_id=h.spids[0])
return False
# NOTE: Could do this runtime to preserve LST.
if h.op_id == Id.Redir_DLessDash:
line = line.lstrip('\t')
if line.rstrip() == h.here_end:
break
lines.append((line_id, line))
parts = []
if h.do_expansion:
# NOTE: We read all lines at once, instead of doing it line-by-line,
# because of cases like this:
# cat <<EOF
# 1 $(echo 2
# echo 3) 4
# EOF
from osh import parse_lib # Avoid circular import
w_parser = parse_lib.MakeWordParserForHereDoc(lines, self.arena)
word = w_parser.ReadHereDocBody()
if not word:
self.AddErrorContext(
'Error reading here doc body: %s', w_parser.Error())
return False
h.body = word
h.was_filled = True
else:
# Each line is a single span. TODO: Add span_id to token.
tokens = [
ast.token(Id.Lit_Chars, line, const.NO_INTEGER)
for _, line in lines]
parts = [ast.LiteralPart(t) for t in tokens]
h.body = ast.CompoundWord(parts)
h.was_filled = True
# No .clear() until Python 3.3.
del self.pending_here_docs[:]
return True
def BraceExpandWords(words):
out = []
for w in words:
if w.tag == word_e.BracedWordTree:
parts_list = _BraceExpand(w.parts)
out.extend(ast.CompoundWord(p) for p in parts_list)
else:
out.append(w)
return out
def _EvalRedirect(self, n):
fd = REDIR_DEFAULT_FD[n.op.id] if n.fd == const.NO_INTEGER else n.fd
if n.tag == redir_e.Redir:
redir_type = REDIR_ARG_TYPES[n.op.id] # could be static in the LST?
if redir_type == redir_arg_type_e.Path:
# NOTE: no globbing. You can write to a file called '*.py'.
val = self.word_ev.EvalWordToString(n.arg_word)
if val.tag != value_e.Str: # TODO: This error never fires
util.error("Redirect filename must be a string, got %s", val)
return None
filename = val.s
if not filename:
# Whether this is fatal depends on errexit.
util.error("Redirect filename can't be empty")
return None
return runtime.PathRedirect(n.op.id, fd, filename)
elif redir_type == redir_arg_type_e.Desc: # e.g. 1>&2
val = self.word_ev.EvalWordToString(n.arg_word)
if val.tag != value_e.Str: # TODO: This error never fires
util.error("Redirect descriptor should be a string, got %s", val)
return None
t = val.s
if not t:
util.error("Redirect descriptor can't be empty")
return None
try:
target_fd = int(t)
except ValueError:
util.error(
"Redirect descriptor should look like an integer, got %s", val)
return None
return runtime.DescRedirect(n.op.id, fd, target_fd)
elif redir_type == redir_arg_type_e.Here: # here word
val = self.word_ev.EvalWordToString(n.arg_word)
assert val.tag == value_e.Str, val
# NOTE: bash and mksh both add \n
return runtime.HereRedirect(fd, val.s + '\n')
else:
raise AssertionError('Unknown redirect op')
elif n.tag == redir_e.HereDoc:
# HACK: Wrap it in a word to evaluate.
w = ast.CompoundWord(n.stdin_parts)
val = self.word_ev.EvalWordToString(w)
assert val.tag == value_e.Str, val
return runtime.HereRedirect(fd, val.s)
else:
raise AssertionError('Unknown redirect type')
def testBraceExpand(self):
w = _assertReadWord(self, 'hi')
results = braces._BraceExpand(w.parts)
self.assertEqual(1, len(results))
for parts in results:
_PrettyPrint(ast.CompoundWord(parts))
print('')
w = _assertReadWord(self, 'B-{a,b}-E')
tree = braces._BraceDetect(w)
self.assertEqual(3, len(tree.parts))
pprint(tree)
results = braces._BraceExpand(tree.parts)
self.assertEqual(2, len(results))
for parts in results:
_PrettyPrint(ast.CompoundWord(parts))
print('')
w = _assertReadWord(self, 'B-{a,={b,c,d}=,e}-E')
tree = braces._BraceDetect(w)
self.assertEqual(3, len(tree.parts))
pprint(tree)
results = braces._BraceExpand(tree.parts)
self.assertEqual(5, len(results))
for parts in results:
_PrettyPrint(ast.CompoundWord(parts))
print('')
w = _assertReadWord(self, 'B-{a,b}-{c,d}-E')
tree = braces._BraceDetect(w)
self.assertEqual(5, len(tree.parts))
pprint(tree)
results = braces._BraceExpand(tree.parts)
self.assertEqual(4, len(results))
for parts in results:
_PrettyPrint(ast.CompoundWord(parts))
print('')
def _ReadArithWord(self):
"""Helper function for ReadArithWord."""
#assert self.token_type != Id.Undefined_Tok
self._Peek()
#print('_ReadArithWord', self.cur_token)
if self.token_kind == Kind.Unknown:
self.AddErrorContext("Unknown token in arith context: %s",
self.cur_token,
token=self.cur_token)
return None, False
elif self.token_kind == Kind.Eof:
# Just return EOF token
w = ast.TokenWord(self.cur_token)
return w, False
#self.AddErrorContext("Unexpected EOF in arith context: %s",
# self.cur_token, token=self.cur_token)
#return None, False
elif self.token_kind == Kind.Ignored:
# Space should be ignored. TODO: change this to SPACE_SPACE and
# SPACE_NEWLINE? or SPACE_TOK.
self._Next(lex_mode_e.ARITH)
return None, True # Tell wrapper to try again
elif self.token_kind in (Kind.Arith, Kind.Right):
# Id.Right_ArithSub IS just a normal token, handled by ArithParser
self._Next(lex_mode_e.ARITH)
w = ast.TokenWord(self.cur_token)
return w, False
elif self.token_kind in (Kind.Lit, Kind.Left):
w = self._ReadCompoundWord(lex_mode=lex_mode_e.ARITH)
if not w:
return None, True
return w, False
elif self.token_kind == Kind.VSub:
part = ast.SimpleVarSub(self.cur_token)
self._Next(lex_mode_e.ARITH)
w = ast.CompoundWord([part])
return w, False
else:
self._BadToken("Unexpected token parsing arith sub: %s",
self.cur_token)
return None, False
raise AssertionError("Shouldn't get here")
def TildeDetect(word):
"""Detect tilde expansion in a word.
It might begin with LiteralPart that needs to be turned into a TildeSubPart.
(It depends on whether the second token begins with slash).
If so, it return a new word. Otherwise return None.
NOTE:
- The regex for Lit_TildeLike could be expanded. Right now it's
conservative, like Lit_Chars without the /.
- It's possible to write this in a mutating style, since only the first token
is changed. But note that we CANNOT know this during lexing.
"""
# NOTE: BracedWordTree, EmptyWord, etc. can't be tilde expanded
if word.tag != word_e.CompoundWord:
return None
assert word.parts, word
part0 = word.parts[0]
if _LiteralPartId(part0) != Id.Lit_TildeLike:
return None
if len(word.parts) == 1: # can't be zero
tilde_part = ast.TildeSubPart(part0.token)
return ast.CompoundWord([tilde_part])
part1 = word.parts[1]
# NOTE: We could inspect the raw tokens.
if _LiteralPartId(part1) == Id.Lit_Chars and part1.token.val.startswith(
'/'):
tilde_part = ast.TildeSubPart(part0.token)
return ast.CompoundWord([tilde_part] + word.parts[1:])
# It could be something like '~foo:bar', which doesn't have a slash.
return None
def testMultiLine(self):
w_parser = InitWordParser("""\
ls foo
# Multiple newlines and comments should be ignored
ls bar
""")
print('--MULTI')
w = w_parser.ReadWord(lex_mode_e.OUTER)
parts = [ast.LiteralPart(ast.token(Id.Lit_Chars, 'ls'))]
test_lib.AssertAsdlEqual(self, ast.CompoundWord(parts), w)
w = w_parser.ReadWord(lex_mode_e.OUTER)
parts = [ast.LiteralPart(ast.token(Id.Lit_Chars, 'foo'))]
test_lib.AssertAsdlEqual(self, ast.CompoundWord(parts), w)
w = w_parser.ReadWord(lex_mode_e.OUTER)
t = ast.token(Id.Op_Newline, '\n')
test_lib.AssertAsdlEqual(self, ast.TokenWord(t), w)
w = w_parser.ReadWord(lex_mode_e.OUTER)
parts = [ast.LiteralPart(ast.token(Id.Lit_Chars, 'ls'))]
test_lib.AssertAsdlEqual(self, ast.CompoundWord(parts), w)
w = w_parser.ReadWord(lex_mode_e.OUTER)
parts = [ast.LiteralPart(ast.token(Id.Lit_Chars, 'bar'))]
test_lib.AssertAsdlEqual(self, ast.CompoundWord(parts), w)
w = w_parser.ReadWord(lex_mode_e.OUTER)
t = ast.token(Id.Op_Newline, '\n')
test_lib.AssertAsdlEqual(self, ast.TokenWord(t), w)
w = w_parser.ReadWord(lex_mode_e.OUTER)
t = ast.token(Id.Eof_Real, '')
test_lib.AssertAsdlEqual(self, ast.TokenWord(t), w)
def ReadHereDocBody(self):
"""
Sort of like Read(), except we're in a double quoted context, but not using
double quotes.
Returns:
CompoundWord. NOTE: We could also just use a DoubleQuotedPart for both
cases?
"""
w = ast.CompoundWord()
dq = self._ReadDoubleQuotedPart(here_doc=True)
if not dq:
self.AddErrorContext('Error parsing here doc body')
return False
w.parts.append(dq)
return w
def LooksLikeAssignment(w):
"""Tests whether a word looks like FOO=bar.
Returns:
(string, CompoundWord) if it looks like FOO=bar
False if it doesn't
s=1
s+=1
s[x]=1
s[x]+=1
a=()
a+=()
a[x]=()
a[x]+=() # Not valid because arrays can't be nested.
NOTE: a[ and s[ might be parsed separately?
"""
assert w.tag == word_e.CompoundWord
if len(w.parts) == 0:
return False
part0 = w.parts[0]
if _LiteralPartId(part0) != Id.Lit_VarLike:
return False
s = part0.token.val
assert s.endswith('=')
if s[-2] == '+':
op = assign_op_e.PlusEqual
name = s[:-2]
else:
op = assign_op_e.Equal
name = s[:-1]
rhs = ast.CompoundWord()
if len(w.parts) == 1:
# This fake SingleQuotedPart is necesssary so that EmptyUnquoted elision
# isn't applied. EMPTY= is like EMPTY=''.
# TODO: This part doesn't have spids, so it might break some invariants.
rhs.parts.append(ast.EmptyPart())
else:
for p in w.parts[1:]:
rhs.parts.append(p)
return name, op, rhs
def _EvalPS4(self):
"""For set -x."""
val = self.mem.GetVar('PS4')
assert val.tag == value_e.Str
s = val.s
if s:
first_char, ps4 = s[0], s[1:]
else:
first_char, ps4 = '+', ' ' # default
try:
ps4_word = self.parse_cache[ps4]
except KeyError:
# We have to parse this at runtime. PS4 should usually remain constant.
w_parser = parse_lib.MakeWordParserForPlugin(ps4, self.arena)
# NOTE: Reading PS4 is just like reading a here doc line. "\n" is
# allowed too. The OUTER mode would stop at spaces, and ReadWord
# doesn't allow lex_mode_e.DQ.
ps4_word = w_parser.ReadHereDocBody()
if not ps4_word:
error_str = '<ERROR: cannot parse PS4>'
t = ast.token(Id.Lit_Chars, error_str, const.NO_INTEGER)
ps4_word = ast.CompoundWord([ast.LiteralPart(t)])
self.parse_cache[ps4] = ps4_word
#print(ps4_word)
# TODO: Repeat first character according process stack depth. Where is
# that stored? In the executor itself? It should be stored along with
# the PID. Need some kind of ShellProcessState or something.
#
# We should come up with a better mechanism. Something like $PROC_INDENT
# and $OIL_XTRACE_PREFIX.
# TODO: Handle runtime errors! For example, you could PS4='$(( 1 / 0 ))'
# <ERROR: cannot evaluate PS4>
prefix = self.word_ev.EvalWordToString(ps4_word)
return first_char, prefix.s
def _EvalPS4(self):
"""For set -x."""
val = self.mem.GetVar('PS4')
assert val.tag == value_e.Str
s = val.s
if s:
first_char, ps4 = s[0], s[1:]
else:
first_char, ps4 = '+', ' ' # default
# NOTE: This cache is slightly broken because aliases are mutable! I think
# thati s more or less harmless though.
try:
ps4_word = self.parse_cache[ps4]
except KeyError:
# We have to parse this at runtime. PS4 should usually remain constant.
w_parser = self.parse_ctx.MakeWordParserForPlugin(ps4, self.arena)
try:
ps4_word = w_parser.ReadPS()
except util.ParseError as e:
error_str = '<ERROR: cannot parse PS4>'
t = ast.token(Id.Lit_Chars, error_str, const.NO_INTEGER)
ps4_word = ast.CompoundWord([ast.LiteralPart(t)])
self.parse_cache[ps4] = ps4_word
#print(ps4_word)
# TODO: Repeat first character according process stack depth. Where is
# that stored? In the executor itself? It should be stored along with
# the PID. Need some kind of ShellProcessState or something.
#
# We should come up with a better mechanism. Something like $PROC_INDENT
# and $OIL_XTRACE_PREFIX.
# TODO: Handle runtime errors! For example, you could PS4='$(( 1 / 0 ))'
# <ERROR: cannot evaluate PS4>
prefix = self.word_ev.EvalWordToString(ps4_word)
return first_char, prefix.s
def _ReadArithWord(self):
"""Helper function for ReadArithWord."""
self._Peek()
if self.token_kind == Kind.Unknown:
p_die('Unexpected token in arithmetic context',
token=self.cur_token)
elif self.token_kind == Kind.Eof:
# Just return EOF token
w = ast.TokenWord(self.cur_token)
return w, False
elif self.token_kind == Kind.Ignored:
# Space should be ignored. TODO: change this to SPACE_SPACE and
# SPACE_NEWLINE? or SPACE_TOK.
self._Next(lex_mode_e.ARITH)
return None, True # Tell wrapper to try again
elif self.token_kind in (Kind.Arith, Kind.Right):
# Id.Right_ArithSub IS just a normal token, handled by ArithParser
self._Next(lex_mode_e.ARITH)
w = ast.TokenWord(self.cur_token)
return w, False
elif self.token_kind in (Kind.Lit, Kind.Left):
w = self._ReadCompoundWord(lex_mode=lex_mode_e.ARITH)
return w, False
elif self.token_kind == Kind.VSub:
part = ast.SimpleVarSub(self.cur_token)
self._Next(lex_mode_e.ARITH)
w = ast.CompoundWord([part])
return w, False
else:
assert False, ("Unexpected token parsing arith sub: %s" %
self.cur_token)
raise AssertionError("Shouldn't get here")
def _ReadCompoundWord(self,
eof_type=Id.Undefined_Tok,
lex_mode=lex_mode_e.OUTER,
empty_ok=True):
"""
Precondition: Looking at the first token of the first word part
Postcondition: Looking at the token after, e.g. space or operator
NOTE: eof_type is necessary because / is a literal, i.e. Lit_Slash, but it
could be an operator delimiting a compound word. Can we change lexer modes
and remove this special case?
"""
#print('_ReadCompoundWord', lex_mode)
word = ast.CompoundWord()
num_parts = 0
done = False
while not done:
allow_done = empty_ok or num_parts != 0
self._Peek()
#print('CW',self.cur_token)
if allow_done and self.token_type == eof_type:
done = True # e.g. for ${foo//pat/replace}
# Keywords like "for" are treated like literals
elif self.token_kind in (Kind.Lit, Kind.KW, Kind.Assign,
Kind.ControlFlow, Kind.BoolUnary,
Kind.BoolBinary):
if self.token_type == Id.Lit_EscapedChar:
part = ast.EscapedLiteralPart(self.cur_token)
else:
part = ast.LiteralPart(self.cur_token)
#part.xspans.append(self.cur_token.span_id)
word.parts.append(part)
if self.token_type == Id.Lit_VarLike:
#print('@', self.cursor)
#print('@', self.cur_token)
t = self.lexer.LookAhead(lex_mode_e.OUTER)
if t.id == Id.Op_LParen:
self.lexer.PushHint(Id.Op_RParen,
Id.Right_ArrayLiteral)
part2 = self._ReadArrayLiteralPart()
if not part2:
self.AddErrorContext(
'_ReadArrayLiteralPart failed')
return False
word.parts.append(part2)
elif self.token_kind == Kind.VSub:
part = ast.SimpleVarSub(self.cur_token)
word.parts.append(part)
elif self.token_kind == Kind.ExtGlob:
part = self._ReadExtGlobPart()
if not part:
return None
word.parts.append(part)
elif self.token_kind == Kind.Left:
#print('_ReadLeftParts')
part = self._ReadLeftParts()
if not part:
return None
word.parts.append(part)
# NOT done yet, will advance below
elif self.token_kind == Kind.Right:
# Still part of the word; will be done on the next iter.
if self.token_type == Id.Right_DoubleQuote:
pass
elif self.token_type == Id.Right_CommandSub:
pass
elif self.token_type == Id.Right_Subshell:
# LEXER HACK for (case x in x) ;; esac )
assert self.next_lex_mode is None # Rewind before it's used
if self.lexer.MaybeUnreadOne():
self.lexer.PushHint(Id.Op_RParen, Id.Right_Subshell)
self._Next(lex_mode)
done = True
else:
done = True
elif self.token_kind == Kind.Ignored:
done = True
else:
# LEXER HACK for unbalanced case clause. 'case foo in esac' is valid,
# so to test for ESAC, we can read ) before getting a chance to
# PushHint(Id.Op_RParen, Id.Right_CasePat). So here we unread one
# token and do it again.
# We get Id.Op_RParen at top level: case x in x) ;; esac
# We get Id.Eof_RParen inside ComSub: $(case x in x) ;; esac )
if self.token_type in (Id.Op_RParen, Id.Eof_RParen):
assert self.next_lex_mode is None # Rewind before it's used
if self.lexer.MaybeUnreadOne():
if self.token_type == Id.Eof_RParen:
# Redo translation
self.lexer.PushHint(Id.Op_RParen, Id.Eof_RParen)
self._Next(lex_mode)
done = True # anything we don't recognize means we're done
if not done:
self._Next(lex_mode)
num_parts += 1
return word
def _BraceDetect(w):
"""
Args:
CompoundWord
Returns:
CompoundWord or None?
Another option:
Grammar:
# an alternative is a literal, possibly empty, or another brace_expr
part = <any part except LiteralPart>
alt = part* | brace_expr
# a brace_expr is group of at least 2 braced and comma-separated
# alternatives, with optional prefix and suffix.
brace_expr = part* '{' alt ',' alt (',' alt)* '}' part*
Problem this grammar: it's not LL(1)
Is it indirect left-recursive?
What's the best way to handle it? LR(1) parser?
Iterative algorithm:
Parse it with a stack?
It's a stack that asserts there is at least one , in between {}
Yeah just go through and when you see {, push another list.
When you get , append to list
When you get } and at least one ',', appendt o list
When you get } without, then pop
If there is no matching }, then abort with error
if not balanced, return error too?
"""
# Errors:
# }a{ - stack depth dips below 0
# {a,b}{ - Stack depth doesn't end at 0
# {a} - no comma, and also not an numeric range
cur_parts = []
stack = []
found = False
for i, part in enumerate(w.parts):
append = True
if part.tag == word_part_e.LiteralPart:
id_ = part.token.id
if id_ == Id.Lit_LBrace:
# Save prefix parts. Start new parts list.
new_frame = _StackFrame(cur_parts)
stack.append(new_frame)
cur_parts = []
append = False
found = True # assume found, but can early exit with None later
elif id_ == Id.Lit_Comma:
# Append a new alternative.
#print('*** Appending after COMMA', cur_parts)
# NOTE: Should we allow this:
# ,{a,b}
# or force this:
# \,{a,b}
# ? We're forcing braces right now but not commas.
if stack:
stack[-1].saw_comma = True
stack[-1].alt_part.words.append(
ast.CompoundWord(cur_parts))
cur_parts = [] # clear
append = False
elif id_ == Id.Lit_RBrace:
# TODO:
# - Detect lack of , -- abort the whole thing
# - Detect {1..10} and {1..10..2}
# - bash and zsh only -- this is NOT implemented by mksh
# - Use a regex on the middle part:
# - digit+ '..' digit+ ( '..' digit+ )?
# - Char ranges are bash only!
#
# ast.BracedIntRangePart()
# ast.CharRangePart()
if not stack: # e.g. echo } -- unbalancd {
return None
if not stack[-1].saw_comma: # {foo} is not a real alternative
return None
stack[-1].alt_part.words.append(ast.CompoundWord(cur_parts))
frame = stack.pop()
cur_parts = frame.cur_parts
cur_parts.append(frame.alt_part)
append = False
if append:
cur_parts.append(part)
if len(stack) != 0:
return None
if found:
return ast.BracedWordTree(cur_parts)
else:
return None
def TildeDetect(word):
"""Detect tilde expansion.
If it needs to include a TildeSubPart, return a new word. Otherwise return
None.
NOTE: This algorithm would be a simpler if
1. We could assume some regex for user names.
2. We didn't need to do brace expansion first, like {~foo,~bar}
OR
- If Lit_Slash were special (it is in the VAROP states, but not OUTER
state). We could introduce another lexer mode after you hit Lit_Tilde?
So we have to scan all LiteralPart instances until they contain a '/'.
http://unix.stackexchange.com/questions/157426/what-is-the-regex-to-validate-linux-users
"It is usually recommended to only use usernames that begin with a lower
case letter or an underscore, followed by lower case letters, digits,
underscores, or dashes. They can end with a dollar sign. In regular
expression terms: [a-z_][a-z0-9_-]*[$]?
On Debian, the only constraints are that usernames must neither start with
a dash ('-') nor contain a colon (':') or a whitespace (space: ' ', end
of line: '\n', tabulation: '\t', etc.). Note that using a slash ('/') may
break the default algorithm for the definition of the user's home
directory.
"""
if not word.parts:
return None
part0 = word.parts[0]
if _LiteralPartId(part0) != Id.Lit_Tilde:
return None
prefix = ''
found_slash = False
# search for the next /
for i in range(1, len(word.parts)):
# Not a literal part, and we did NOT find a slash. So there is no
# TildeSub applied. This would be something like ~X$var, ~$var,
# ~$(echo), etc.. The slash is necessary.
if word.parts[i].tag != word_part_e.LiteralPart:
return None
val = word.parts[i].token.val
p = val.find('/')
if p == -1: # no slash yet
prefix += val
elif p >= 0:
# e.g. for ~foo!bar/baz, extract "bar"
# NOTE: requires downcast to LiteralPart
pre, post = val[:p], val[p:]
prefix += pre
tilde_part = ast.TildeSubPart(prefix)
# NOTE: no span_id here. It would be nicer to use a different algorithm
# that didn't require this.
t = ast.token(Id.Lit_Chars, post, const.NO_INTEGER)
remainder_part = ast.LiteralPart(t)
found_slash = True
break
w = ast.CompoundWord()
if found_slash:
w.parts.append(tilde_part)
w.parts.append(remainder_part)
j = i + 1
while j < len(word.parts):
w.parts.append(word.parts[j])
j += 1
else:
# The whole thing is a tilde sub, e.g. ~foo or ~foo!bar
w.parts.append(ast.TildeSubPart(prefix))
return w
