def Read(argv, splitter, mem):
arg, i = READ_SPEC.Parse(argv)
names = argv[i:]
if arg.n is not None: # read a certain number of bytes
try:
name = names[0]
except IndexError:
name = 'REPLY' # default variable name
s = posix.read(sys.stdin.fileno(), arg.n)
#log('read -n: %s = %s', name, s)
state.SetLocalString(mem, name, s)
# NOTE: Even if we don't get n bytes back, there is no error?
return 0
if not names:
names.append('REPLY')
# leftover words assigned to the last name
max_results = len(names)
# We have to read more than one line if there is a line continuation (and
# it's not -r).
parts = []
join_next = False
while True:
line = ReadLineFromStdin()
#log('LINE %r', line)
if not line: # EOF
status = 1
break
if line.endswith('\n'): # strip trailing newline
line = line[:-1]
status = 0
else:
# odd bash behavior: fail even if we can set variables.
status = 1
spans = splitter.SplitForRead(line, not arg.r)
done, join_next = _AppendParts(line, spans, max_results, join_next,
parts)
#log('PARTS %s continued %s', parts, continued)
if done:
break
for i in xrange(max_results):
try:
s = parts[i]
except IndexError:
s = '' # if there are too many variables
#log('read: %s = %s', names[i], s)
state.SetLocalString(mem, names[i], s)
return status
def InitEvaluator():
word_ev = test_lib.InitWordEvaluator()
state.SetLocalString(word_ev.mem, 'x', '- -- ---')
state.SetLocalString(word_ev.mem, 'y', 'y yy')
state.SetLocalString(word_ev.mem, 'empty', '')
state.SetLocalString(word_ev.mem, 'binding', 'spam=eggs')
state.SetLocalString(word_ev.mem, 'binding_with_spaces',
'x=green eggs and ham')
word_ev.mem.SetArgv(['x', 'foo', 'spam=eggs'])
return word_ev
def Read(argv, mem):
# TODO:
# - Use IFS instead of Python's split().
arg, i = READ_SPEC.Parse(argv)
if not arg.r:
util.warn('*** read without -r not implemented ***')
names = argv[i:]
if arg.n is not None:
try:
name = names[0]
except IndexError:
name = 'REPLY' # default variable name
s = os.read(sys.stdin.fileno(), arg.n)
#log('read -n: %s = %s', name, s)
state.SetLocalString(mem, name, s)
# NOTE: Even if we don't get n bytes back, there is no error?
return 0
line = sys.stdin.readline()
if not line: # EOF
return 1
if line.endswith('\n'): # strip trailing newline
line = line[:-1]
status = 0
else:
# odd bash behavior: fail even if we can set variables.
status = 1
# leftover words assigned to the last name
n = len(names)
strs = line.split(None, n - 1)
# TODO: Use REPLY variable here too?
for i in xrange(n):
try:
s = strs[i]
except IndexError:
s = '' # if there are too many variables
#log('read: %s = %s', names[i], s)
state.SetLocalString(mem, names[i], s)
return status
def Read(argv, mem):
# TODO:
# - parse flags.
# - Use IFS instead of Python's split().
names = argv
line = sys.stdin.readline()
if not line: # EOF
return 1
if line.endswith('\n'): # strip trailing newline
line = line[:-1]
status = 0
else:
# odd bash behavior: fail even if we can set variables.
status = 1
# leftover words assigned to the last name
n = len(names)
strs = line.split(None, n - 1)
for i in xrange(n):
try:
s = strs[i]
except IndexError:
s = '' # if there are too many variables
state.SetLocalString(mem, names[i], s)
return status
def _Dispatch(self, node, fork_external):
# If we call RunCommandSub in a recursive call to the executor, this will
# be set true (if strict-errexit is false). But it only lasts for one
# command.
self.check_command_sub_status = False
#argv0 = None # for error message
check_errexit = False # for errexit
if node.tag == command_e.SimpleCommand:
check_errexit = True
# Find span_id for a basic implementation of $LINENO, e.g.
# PS4='+$SOURCE_NAME:$LINENO:'
# NOTE: osh2oil uses node.more_env, but we don't need that.
span_id = const.NO_INTEGER
if node.words:
first_word = node.words[0]
span_id = word.LeftMostSpanForWord(first_word)
self.mem.SetCurrentSpanId(span_id)
# PROBLEM: We want to log argv in 'xtrace' mode, but we may have already
# redirected here, which screws up logging. For example, 'echo hi
# >/dev/null 2>&1'. We want to evaluate argv and log it BEFORE applying
# redirects.
# Another problem:
# - tracing can be called concurrently from multiple processes, leading
# to overlap. Maybe have a mode that creates a file per process.
# xtrace-proc
# - line numbers for every command would be very nice. But then you have
# to print the filename too.
words = braces.BraceExpandWords(node.words)
argv = self.word_ev.EvalWordSequence(words)
# This comes before evaluating env, in case there are problems evaluating
# it. We could trace the env separately? Also trace unevaluated code
# with set-o verbose?
self.tracer.OnSimpleCommand(argv)
if node.more_env:
self.mem.PushTemp()
try:
for env_pair in node.more_env:
val = self.word_ev.EvalWordToString(env_pair.val)
# Set each var so the next one can reference it. Example:
# FOO=1 BAR=$FOO ls /
self.mem.SetVar(ast.LhsName(env_pair.name), val,
(var_flags_e.Exported,), scope_e.TempEnv)
# NOTE: This might never return! In the case of fork_external=False.
status = self._RunSimpleCommand(argv, fork_external, span_id)
finally:
if node.more_env:
self.mem.PopTemp()
elif node.tag == command_e.Sentence:
# Don't check_errexit since this isn't a real node!
if node.terminator.id == Id.Op_Semi:
status = self._Execute(node.child)
else:
status = self._RunJobInBackground(node.child)
elif node.tag == command_e.Pipeline:
check_errexit = True
if node.stderr_indices:
raise NotImplementedError('|&')
if node.negated:
self._PushErrExit()
try:
status2 = self._RunPipeline(node)
finally:
self._PopErrExit()
# errexit is disabled for !.
check_errexit = False
status = 1 if status2 == 0 else 0
else:
status = self._RunPipeline(node)
elif node.tag == command_e.Subshell:
check_errexit = True
# This makes sure we don't waste a process if we'd launch one anyway.
p = self._MakeProcess(node.child)
status = p.Run(self.waiter)
elif node.tag == command_e.DBracket:
check_errexit = True
result = self.bool_ev.Eval(node.expr)
status = 0 if result else 1
elif node.tag == command_e.DParen:
check_errexit = True
i = self.arith_ev.Eval(node.child)
status = 0 if i != 0 else 1
elif node.tag == command_e.Assignment:
flags = word_compile.ParseAssignFlags(node.flags)
if node.keyword == Id.Assign_Local:
lookup_mode = scope_e.LocalOnly
# typeset and declare are synonyms? I see typeset -a a=() the most.
elif node.keyword in (Id.Assign_Declare, Id.Assign_Typeset):
# declare is like local, except it can also be used outside functions?
if var_flags_e.Global in flags:
lookup_mode = scope_e.GlobalOnly
else:
lookup_mode = scope_e.LocalOnly
elif node.keyword == Id.Assign_Readonly:
lookup_mode = scope_e.Dynamic
flags.append(var_flags_e.ReadOnly)
elif node.keyword == Id.Assign_None: # mutate existing local or global
lookup_mode = scope_e.Dynamic
else:
raise AssertionError(node.keyword)
for pair in node.pairs:
if pair.op == assign_op_e.PlusEqual:
assert pair.rhs, pair.rhs # I don't think a+= is valid?
val = self.word_ev.EvalRhsWord(pair.rhs)
old_val, lval = expr_eval.EvalLhsAndLookup(pair.lhs, self.arith_ev,
self.mem, self.exec_opts)
sig = (old_val.tag, val.tag)
if sig == (value_e.Undef, value_e.Str):
pass # val is RHS
elif sig == (value_e.Undef, value_e.StrArray):
pass # val is RHS
elif sig == (value_e.Str, value_e.Str):
val = runtime.Str(old_val.s + val.s)
elif sig == (value_e.Str, value_e.StrArray):
e_die("Can't append array to string")
elif sig == (value_e.StrArray, value_e.Str):
e_die("Can't append string to array")
elif sig == (value_e.StrArray, value_e.StrArray):
val = runtime.StrArray(old_val.strs + val.strs)
else: # plain assignment
spid = pair.spids[0] # Source location for tracing
lval = self._EvalLhs(pair.lhs, spid, lookup_mode)
# RHS can be a string or array.
if pair.rhs:
val = self.word_ev.EvalRhsWord(pair.rhs)
assert isinstance(val, runtime.value), val
else: # e.g. 'readonly x' or 'local x'
val = None
# NOTE: In bash and mksh, declare -a myarray makes an empty cell with
# Undef value, but the 'array' attribute.
#log('setting %s to %s with flags %s', lval, val, flags)
self.mem.SetVar(lval, val, flags, lookup_mode,
strict_array=self.exec_opts.strict_array)
# Assignment always appears to have a spid.
if node.spids:
current_spid = node.spids[0]
else:
current_spid = const.NO_INTEGER
self.mem.SetCurrentSpanId(current_spid)
self.tracer.OnAssignment(lval, pair.op, val, flags, lookup_mode)
# PATCH to be compatible with existing shells: If the assignment had a
# command sub like:
#
# s=$(echo one; false)
#
# then its status will be in mem.last_status, and we can check it here.
# If there was NOT a command sub in the assignment, then we don't want to
# check it.
if node.keyword == Id.Assign_None: # mutate existing local or global
# Only do this if there was a command sub? How? Look at node?
# Set a flag in mem? self.mem.last_status or
if self.check_command_sub_status:
self._CheckStatus(self.mem.last_status, node)
# A global assignment shouldn't clear $?.
status = self.mem.last_status
else:
status = 0
else:
# To be compatible with existing shells, local assignments DO clear
# $?. Even in strict mode, we don't need to bother setting
# check_errexit = True, because we would have already checked the
# command sub in RunCommandSub.
status = 0
# TODO: maybe we should have a "sane-status" that respects this:
# false; echo $?; local f=x; echo $?
elif node.tag == command_e.ControlFlow:
if node.arg_word: # Evaluate the argument
val = self.word_ev.EvalWordToString(node.arg_word)
assert val.tag == value_e.Str
arg = int(val.s) # They all take integers
else:
arg = 0 # return 0, exit 0, break 0 levels, etc.
# NOTE: We don't do anything about a top-level 'return' here. Unlike in
# bash, that is OK. If you can return from a sourced script, it makes
# sense to return from a main script.
ok = True
tok = node.token
if (tok.id in (Id.ControlFlow_Break, Id.ControlFlow_Continue) and
self.loop_level == 0):
ok = False
msg = 'Invalid control flow at top level'
if ok:
raise _ControlFlow(tok, arg)
if self.exec_opts.strict_control_flow:
e_die(msg, token=tok)
else:
# Only print warnings, never fatal.
# Bash oddly only exits 1 for 'return', but no other shell does.
ui.PrintFilenameAndLine(tok.span_id, self.arena)
util.warn(msg)
status = 0
# The only difference between these two is that CommandList has no
# redirects. We already took care of that above.
elif node.tag in (command_e.CommandList, command_e.BraceGroup):
status = self._ExecuteList(node.children)
check_errexit = False
elif node.tag == command_e.AndOr:
# NOTE: && and || have EQUAL precedence in command mode. See case #13
# in dbracket.test.sh.
left = node.children[0]
# Suppress failure for every child except the last one.
self._PushErrExit()
try:
status = self._Execute(left)
finally:
self._PopErrExit()
i = 1
n = len(node.children)
while i < n:
#log('i %d status %d', i, status)
child = node.children[i]
op_id = node.ops[i-1]
#log('child %s op_id %s', child, op_id)
if op_id == Id.Op_DPipe and status == 0:
i += 1
continue # short circuit
elif op_id == Id.Op_DAmp and status != 0:
i += 1
continue # short circuit
if i == n - 1: # errexit handled differently for last child
status = self._Execute(child)
check_errexit = True
else:
self._PushErrExit()
try:
status = self._Execute(child)
finally:
self._PopErrExit()
i += 1
elif node.tag == command_e.WhileUntil:
if node.keyword.id == Id.KW_While:
_DonePredicate = lambda status: status != 0
else:
_DonePredicate = lambda status: status == 0
status = 0
self.loop_level += 1
try:
while True:
self._PushErrExit()
try:
cond_status = self._ExecuteList(node.cond)
finally:
self._PopErrExit()
done = cond_status != 0
if _DonePredicate(cond_status):
break
try:
status = self._Execute(node.body) # last one wins
except _ControlFlow as e:
if e.IsBreak():
status = 0
break
elif e.IsContinue():
status = 0
continue
else: # return needs to pop up more
raise
finally:
self.loop_level -= 1
elif node.tag == command_e.ForEach:
iter_name = node.iter_name
if node.do_arg_iter:
iter_list = self.mem.GetArgv()
else:
words = braces.BraceExpandWords(node.iter_words)
iter_list = self.word_ev.EvalWordSequence(words)
# We need word splitting and so forth
# NOTE: This expands globs too. TODO: We should pass in a Globber()
# object.
status = 0 # in case we don't loop
self.loop_level += 1
try:
for x in iter_list:
#log('> ForEach setting %r', x)
state.SetLocalString(self.mem, iter_name, x)
#log('<')
try:
status = self._Execute(node.body) # last one wins
except _ControlFlow as e:
if e.IsBreak():
status = 0
break
elif e.IsContinue():
status = 0
else: # return needs to pop up more
raise
finally:
self.loop_level -= 1
elif node.tag == command_e.ForExpr:
status = 0
init, cond, body, update = node.init, node.cond, node.body, node.update
if init:
self.arith_ev.Eval(init)
self.loop_level += 1
try:
while True:
if cond:
b = self.arith_ev.Eval(cond)
if not b:
break
try:
status = self._Execute(body)
except _ControlFlow as e:
if e.IsBreak():
status = 0
break
elif e.IsContinue():
status = 0
else: # return needs to pop up more
raise
if update:
self.arith_ev.Eval(update)
finally:
self.loop_level -= 1
elif node.tag == command_e.DoGroup:
status = self._ExecuteList(node.children)
check_errexit = False # not real statements
elif node.tag == command_e.FuncDef:
# NOTE: Would it make sense to evaluate the redirects BEFORE entering?
# It will save time on function calls.
self.funcs[node.name] = node
status = 0
elif node.tag == command_e.If:
done = False
for arm in node.arms:
self._PushErrExit()
try:
status = self._ExecuteList(arm.cond)
finally:
self._PopErrExit()
if status == 0:
status = self._ExecuteList(arm.action)
done = True
break
# TODO: The compiler should flatten this
if not done and node.else_action is not None:
status = self._ExecuteList(node.else_action)
elif node.tag == command_e.NoOp:
status = 0 # make it true
elif node.tag == command_e.Case:
val = self.word_ev.EvalWordToString(node.to_match)
to_match = val.s
status = 0 # If there are no arms, it should be zero?
done = False
for arm in node.arms:
for pat_word in arm.pat_list:
# NOTE: Is it OK that we're evaluating these as we go?
# TODO: case "$@") shouldn't succeed? That's a type error?
# That requires strict-array?
pat_val = self.word_ev.EvalWordToString(pat_word, do_fnmatch=True)
#log('Matching word %r against pattern %r', to_match, pat_val.s)
if libc.fnmatch(pat_val.s, to_match):
status = self._ExecuteList(arm.action)
done = True # TODO: Parse ;;& and for fallthrough and such?
break # Only execute action ONCE
if done:
break
elif node.tag == command_e.TimeBlock:
# TODO:
# - When do we need RUSAGE_CHILDREN?
# - Respect TIMEFORMAT environment variable.
# "If this variable is not set, Bash acts as if it had the value"
# $'\nreal\t%3lR\nuser\t%3lU\nsys\t%3lS'
# "A trailing newline is added when the format string is displayed."
start_t = time.time() # calls gettimeofday() under the hood
start_u = resource.getrusage(resource.RUSAGE_SELF)
status = self._Execute(node.pipeline)
end_t = time.time()
end_u = resource.getrusage(resource.RUSAGE_SELF)
real = end_t - start_t
user = end_u.ru_utime - start_u.ru_utime
sys_ = end_u.ru_stime - start_u.ru_stime
libc.print_time(real, user, sys_)
else:
raise NotImplementedError(node.__class__.__name__)
return status, check_errexit
def InitEvaluator(): word_ev = test_lib.InitWordEvaluator() state.SetLocalString(word_ev.mem, 'x', 'xxx') state.SetLocalString(word_ev.mem, 'y', 'yyy') return word_ev
def Run(self, cmd_val):
# type: (cmd_value__Argv) -> int
arg, i = READ_SPEC.ParseCmdVal(cmd_val)
names = cmd_val.argv[i:]
if arg.n is not None: # read a certain number of bytes
stdin = sys.stdin.fileno()
try:
name = names[0]
except IndexError:
name = 'REPLY' # default variable name
s = ""
if sys.stdin.isatty(): # set stdin to read in unbuffered mode
orig_attrs = termios.tcgetattr(stdin)
attrs = termios.tcgetattr(stdin)
# disable canonical (buffered) mode
# see `man termios` for an extended discussion
attrs[3] &= ~termios.ICANON
try:
termios.tcsetattr(stdin, termios.TCSANOW, attrs)
# posix.read always returns a single character in unbuffered mode
while arg.n > 0:
s += posix.read(stdin, 1)
arg.n -= 1
finally:
termios.tcsetattr(stdin, termios.TCSANOW, orig_attrs)
else:
s_len = 0
while arg.n > 0:
buf = posix.read(stdin, arg.n)
# EOF
if buf == '':
break
arg.n -= len(buf)
s += buf
state.SetLocalString(self.mem, name, s)
# NOTE: Even if we don't get n bytes back, there is no error?
return 0
if not names:
names.append('REPLY')
# leftover words assigned to the last name
if arg.a:
max_results = 0 # no max
else:
max_results = len(names)
# We have to read more than one line if there is a line continuation (and
# it's not -r).
parts = []
join_next = False
while True:
line = ReadLineFromStdin()
#log('LINE %r', line)
if not line: # EOF
status = 1
break
if line.endswith('\n'): # strip trailing newline
line = line[:-1]
status = 0
else:
# odd bash behavior: fail even if we can set variables.
status = 1
spans = self.splitter.SplitForRead(line, not arg.r)
done, join_next = _AppendParts(line, spans, max_results, join_next,
parts)
#log('PARTS %s continued %s', parts, continued)
if done:
break
if arg.a:
state.SetArrayDynamic(self.mem, arg.a, parts)
else:
for i in xrange(max_results):
try:
s = parts[i]
except IndexError:
s = '' # if there are too many variables
#log('read: %s = %s', names[i], s)
state.SetStringDynamic(self.mem, names[i], s)
return status
def _EvalBracedVarSub(self, part, part_vals, quoted):
"""
Args:
part_vals: output param to append to.
"""
# We have four types of operator that interact.
#
# 1. Bracket: value -> (value, bool maybe_decay_array)
#
# 2. Then these four cases are mutually exclusive:
#
# a. Prefix length: value -> value
# b. Test: value -> part_value[]
# c. Other Suffix: value -> value
# d. no operator: you have a value
#
# That is, we don't have both prefix and suffix operators.
#
# 3. Process maybe_decay_array here before returning.
maybe_decay_array = False # for $*, ${a[*]}, etc.
var_name = None # For ${foo=default}
# 1. Evaluate from (var_name, var_num, token Id) -> value
if part.token.id == Id.VSub_Name:
var_name = part.token.val
val = self.mem.GetVar(var_name)
#log('EVAL NAME %s -> %s', var_name, val)
elif part.token.id == Id.VSub_Number:
var_num = int(part.token.val)
val = self._EvalVarNum(var_num)
else:
# $* decays
val, maybe_decay_array = self._EvalSpecialVar(
part.token.id, quoted)
# 2. Bracket: value -> (value v, bool maybe_decay_array)
# maybe_decay_array is for joining ${a[*]} and unquoted ${a[@]} AFTER
# suffix ops are applied. If we take the length with a prefix op, the
# distinction is ignored.
if part.bracket_op:
if part.bracket_op.tag == bracket_op_e.WholeArray:
op_id = part.bracket_op.op_id
if op_id == Id.Lit_At:
if not quoted:
maybe_decay_array = True # ${a[@]} decays but "${a[@]}" doesn't
if val.tag == value_e.Undef:
val = self._EmptyStrArrayOrError(part.token)
elif val.tag == value_e.Str:
e_die("Can't index string with @: %r", val, part=part)
elif val.tag == value_e.StrArray:
# TODO: Is this a no-op? Just leave 'val' alone.
val = runtime.StrArray(val.strs)
elif op_id == Id.Arith_Star:
maybe_decay_array = True # both ${a[*]} and "${a[*]}" decay
if val.tag == value_e.Undef:
val = self._EmptyStrArrayOrError(part.token)
elif val.tag == value_e.Str:
e_die("Can't index string with *: %r", val, part=part)
elif val.tag == value_e.StrArray:
# TODO: Is this a no-op? Just leave 'val' alone.
# ${a[*]} or "${a[*]}" : maybe_decay_array is always true
val = runtime.StrArray(val.strs)
else:
raise AssertionError(op_id) # unknown
elif part.bracket_op.tag == bracket_op_e.ArrayIndex:
anode = part.bracket_op.expr
if val.tag == value_e.Undef:
pass # it will be checked later
elif val.tag == value_e.Str:
# Bash treats any string as an array, so we can't add our own
# behavior here without making valid OSH invalid bash.
e_die("Can't index string %r with integer",
part.token.val,
token=part.token)
elif val.tag == value_e.StrArray:
index = self.arith_ev.Eval(anode)
try:
# could be None because representation is sparse
s = val.strs[index]
except IndexError:
s = None
if s is None:
val = runtime.Undef()
else:
val = runtime.Str(s)
elif val.tag == value_e.AssocArray:
key = self.arith_ev.Eval(anode, int_coerce=False)
try:
val = runtime.Str(val.d[key])
except KeyError:
val = runtime.Undef()
else:
raise AssertionError(val.__class__.__name__)
else:
raise AssertionError(part.bracket_op.tag)
if part.prefix_op:
val = self._EmptyStrOrError(val) # maybe error
val = self._ApplyPrefixOp(val, part.prefix_op)
# NOTE: When applying the length operator, we can't have a test or
# suffix afterward. And we don't want to decay the array
elif part.suffix_op:
op = part.suffix_op
if op.tag == suffix_op_e.StringNullary:
if op.op_id == Id.VOp0_P:
# TODO: Use dependency injection
#val = self.prompt._EvalPS1(val)
prompt = ui.PROMPT.EvalPrompt(val)
val = runtime.Str(prompt)
else:
raise NotImplementedError(op.op_id)
elif op.tag == suffix_op_e.StringUnary:
if LookupKind(part.suffix_op.op_id) == Kind.VTest:
# TODO: Change style to:
# if self._ApplyTestOp(...)
# return
# It should return whether anything was done. If not, we continue to
# the end, where we might throw an error.
assign_part_vals, effect = self._ApplyTestOp(
val, part.suffix_op, quoted, part_vals)
# NOTE: Splicing part_values is necessary because of code like
# ${undef:-'a b' c 'd # e'}. Each part_value can have a different
# do_glob/do_elide setting.
if effect == effect_e.SpliceParts:
return # EARLY RETURN, part_vals mutated
elif effect == effect_e.SpliceAndAssign:
if var_name is None:
# TODO: error context
e_die("Can't assign to special variable")
else:
# NOTE: This decays arrays too! 'set -o strict_array' could
# avoid it.
rhs_str = _DecayPartValuesToString(
assign_part_vals, self.splitter.GetJoinChar())
state.SetLocalString(self.mem, var_name, rhs_str)
return # EARLY RETURN, part_vals mutated
elif effect == effect_e.Error:
raise NotImplementedError
else:
# The old one
#val = self._EmptyStringPartOrError(part_val, quoted)
pass # do nothing, may still be undefined
else:
val = self._EmptyStrOrError(val) # maybe error
# Other suffix: value -> value
val = self._ApplyUnarySuffixOp(val, part.suffix_op)
elif op.tag == suffix_op_e.PatSub: # PatSub, vectorized
val = self._EmptyStrOrError(val) # ${undef//x/y}
pat_val = self.EvalWordToString(op.pat, do_fnmatch=True)
assert pat_val.tag == value_e.Str, pat_val
if op.replace:
replace_val = self.EvalWordToString(op.replace,
do_fnmatch=True)
assert replace_val.tag == value_e.Str, replace_val
replace_str = replace_val.s
else:
replace_str = ''
# Either GlobReplacer or ConstStringReplacer
replacer = libstr.MakeReplacer(pat_val.s, replace_str,
op.spids[0])
if val.tag == value_e.Str:
s = replacer.Replace(val.s, op)
val = runtime.Str(s)
elif val.tag == value_e.StrArray:
strs = []
for s in val.strs:
if s is not None:
strs.append(replacer.Replace(s, op))
val = runtime.StrArray(strs)
else:
raise AssertionError(val.__class__.__name__)
elif op.tag == suffix_op_e.Slice:
val = self._EmptyStrOrError(val) # ${undef:3:1}
if op.begin:
begin = self.arith_ev.Eval(op.begin)
else:
begin = 0
if op.length:
length = self.arith_ev.Eval(op.length)
else:
length = None
if val.tag == value_e.Str: # Slice UTF-8 characters in a string.
s = val.s
try:
if begin < 0:
# It could be negative if we compute unicode length, but that's
# confusing.
# TODO: Instead of attributing it to the word part, it would be
# better if we attributed it to arith_expr begin.
raise util.InvalidSlice(
"The start index of a string slice can't be negative: %d",
begin,
part=part)
byte_begin = libstr.AdvanceUtf8Chars(s, begin, 0)
if length is None:
byte_end = len(s)
else:
if length < 0:
# TODO: Instead of attributing it to the word part, it would be
# better if we attributed it to arith_expr begin.
raise util.InvalidSlice(
"The length of a string slice can't be negative: %d",
length,
part=part)
byte_end = libstr.AdvanceUtf8Chars(
s, length, byte_begin)
except (util.InvalidSlice, util.InvalidUtf8) as e:
if self.exec_opts.strict_word_eval:
raise
else:
# TODO:
# - We don't see the error location here, but we see it when set
# -o strict-word-eval.
# - Doesn't make the command exit with 1. It just sets the word
# to empty string.
util.warn(e.UserErrorString())
substr = '' # error condition
else:
substr = s[byte_begin:byte_end]
val = runtime.Str(substr)
elif val.tag == value_e.StrArray: # Slice array entries.
# NOTE: unset elements don't count towards the length.
strs = []
for s in val.strs[begin:]:
if s is not None:
strs.append(s)
if len(
strs
) == length: # never true for unspecified length
break
val = runtime.StrArray(strs)
else:
raise AssertionError(
val.__class__.__name__) # Not possible
# After applying suffixes, process maybe_decay_array here.
if maybe_decay_array and val.tag == value_e.StrArray:
val = self._DecayArray(val)
# For the case where there are no prefix or suffix ops.
val = self._EmptyStrOrError(val)
# For example, ${a} evaluates to value_t.Str(), but we want a
# part_value.StringPartValue.
part_val = _ValueToPartValue(val, quoted)
part_vals.append(part_val)
def _EvalBracedVarSub(self, part, part_vals, quoted):
"""
Args:
part_vals: output param to append to.
"""
# We have four types of operator that interact.
#
# 1. Bracket: value -> (value, bool decay_array)
#
# 2. Then these four cases are mutually exclusive:
#
# a. Prefix length: value -> value
# b. Test: value -> part_value[]
# c. Other Suffix: value -> value
# d. no operator: you have a value
#
# That is, we don't have both prefix and suffix operators.
#
# 3. Process decay_array here before returning.
decay_array = False # for $*, ${a[*]}, etc.
var_name = None # For ${foo=default}
# 1. Evaluate from (var_name, var_num, token Id) -> value
if part.token.id == Id.VSub_Name:
var_name = part.token.val
val = self.mem.GetVar(var_name)
#log('EVAL NAME %s -> %s', var_name, val)
elif part.token.id == Id.VSub_Number:
var_num = int(part.token.val)
val = self._EvalVarNum(var_num)
else:
# $* decays
val, decay_array = self._EvalSpecialVar(part.token.id, quoted)
# 2. Bracket: value -> (value v, bool decay_array)
# decay_array is for joining ${a[*]} and unquoted ${a[@]} AFTER suffix ops
# are applied. If we take the length with a prefix op, the distinction is
# ignored.
if part.bracket_op:
if part.bracket_op.tag == bracket_op_e.WholeArray:
op_id = part.bracket_op.op_id
if op_id == Id.Lit_At:
if not quoted:
decay_array = True # ${a[@]} decays but "${a[@]}" doesn't
if val.tag == value_e.Undef:
val = self._EmptyStrArrayOrError(part.token)
elif val.tag == value_e.Str:
e_die("Can't index string with @: %r", val, part=part)
elif val.tag == value_e.StrArray:
val = runtime.StrArray(val.strs)
elif op_id == Id.Arith_Star:
decay_array = True # both ${a[*]} and "${a[*]}" decay
if val.tag == value_e.Undef:
val = self._EmptyStrArrayOrError(part.token)
elif val.tag == value_e.Str:
e_die("Can't index string with *: %r", val, part=part)
elif val.tag == value_e.StrArray:
# Always decay_array with ${a[*]} or "${a[*]}"
val = runtime.StrArray(val.strs)
else:
raise AssertionError(op_id) # unknown
elif part.bracket_op.tag == bracket_op_e.ArrayIndex:
anode = part.bracket_op.expr
index = self.arith_ev.Eval(anode)
if val.tag == value_e.Undef:
pass # it will be checked later
elif val.tag == value_e.Str:
# TODO: Implement this as an extension. Requires unicode support.
# Bash treats it as an array.
e_die("Can't index string %r with integer", part.token.val)
elif val.tag == value_e.StrArray:
try:
s = val.strs[index]
except IndexError:
val = runtime.Undef()
else:
val = runtime.Str(s)
else:
raise AssertionError(part.bracket_op.tag)
if part.prefix_op:
val = self._EmptyStrOrError(val) # maybe error
val = self._ApplyPrefixOp(val, part.prefix_op)
# At least for length, we can't have a test or suffix afterward.
elif part.suffix_op:
op = part.suffix_op
if op.tag == suffix_op_e.StringUnary:
if LookupKind(part.suffix_op.op_id) == Kind.VTest:
# TODO: Change style to:
# if self._ApplyTestOp(...)
# return
# It should return whether anything was done. If not, we continue to
# the end, where we might throw an error.
assign_part_vals, effect = self._ApplyTestOp(val, part.suffix_op,
quoted, part_vals)
# NOTE: Splicing part_values is necessary because of code like
# ${undef:-'a b' c 'd # e'}. Each part_value can have a different
# do_glob/do_elide setting.
if effect == Effect.SpliceParts:
return # EARLY RETURN, part_vals mutated
elif effect == Effect.SpliceAndAssign:
if var_name is None:
# TODO: error context
e_die("Can't assign to special variable")
else:
# NOTE: This decays arrays too! 'set -o strict_array' could
# avoid it.
rhs_str = _DecayPartValuesToString(assign_part_vals,
self.splitter.GetJoinChar())
state.SetLocalString(self.mem, var_name, rhs_str)
return # EARLY RETURN, part_vals mutated
elif effect == Effect.Error:
raise NotImplementedError
else:
# The old one
#val = self._EmptyStringPartOrError(part_val, quoted)
pass # do nothing, may still be undefined
else:
val = self._EmptyStrOrError(val) # maybe error
# Other suffix: value -> value
val = self._ApplyUnarySuffixOp(val, part.suffix_op)
elif op.tag == suffix_op_e.PatSub: # PatSub, vectorized
val = self._EmptyStrOrError(val)
pat_val = self.EvalWordToString(op.pat, do_fnmatch=True)
assert pat_val.tag == value_e.Str, pat_val
if op.replace:
replace_val = self.EvalWordToString(op.replace, do_fnmatch=True)
assert replace_val.tag == value_e.Str, replace_val
replace_str = replace_val.s
else:
replace_str = ''
pat = pat_val.s
if val.tag == value_e.Str:
s = libstr.PatSub(val.s, op, pat, replace_str)
val = runtime.Str(s)
elif val.tag == value_e.StrArray:
strs = []
for s in val.strs:
strs.append(libstr.PatSub(s, op, pat, replace_str))
val = runtime.StrArray(strs)
else:
raise AssertionError(val.__class__.__name__)
elif op.tag == suffix_op_e.Slice:
# NOTE: The beginning can be negative, but Python handles this. Might
# want to make it explicit.
# TODO: Check out of bounds errors? begin > end?
if op.begin:
begin = self.arith_ev.Eval(op.begin)
else:
begin = 0
if op.length:
length = self.arith_ev.Eval(op.length)
end = begin + length
else:
end = None # Python supports None as the end
if val.tag == value_e.Str: # Slice characters in a string.
# TODO: Need to support unicode? Write spec # tests.
val = runtime.Str(val.s[begin : end])
elif val.tag == value_e.StrArray: # Slice array entries.
val = runtime.StrArray(val.strs[begin : end])
else:
raise AssertionError(val.__class__.__name__)
# After applying suffixes, process decay_array here.
if decay_array:
val = self._DecayArray(val)
# No prefix or suffix ops
val = self._EmptyStrOrError(val)
# For example, ${a} evaluates to value_t.Str(), but we want a
# part_value.StringPartValue.
part_val = _ValueToPartValue(val, quoted)
part_vals.append(part_val)
def _Dispatch(self, node, fork_external):
argv0 = None # for error message
check_errexit = True # for errexit
if node.tag == command_e.SimpleCommand:
# PROBLEM: We want to log argv in 'xtrace' mode, but we may have already
# redirected here, which screws up loggnig. For example, 'echo hi
# >/dev/null 2>&1'. We want to evaluate argv and log it BEFORE applying
# redirects.
# Another problem:
# - tracing can be called concurrently from multiple processes, leading
# to overlap. Maybe have a mode that creates a file per process.
# xtrace-proc
# - line numbers for every command would be very nice. But then you have
# to print the filename too.
words = braces.BraceExpandWords(node.words)
argv = self.ev.EvalWordSequence(words)
if argv:
argv0 = argv[0]
environ = self.mem.GetExported()
self._EvalEnv(node.more_env, environ)
if self.exec_opts.xtrace:
log('+ %s', argv)
#print('+ %s' % argv, file=sys.stderr)
#print('+ %s' % argv, file=self.XFILE)
#os.write(2, '+ %s\n' % argv)
status = self._RunSimpleCommand(argv, environ, fork_external)
if self.exec_opts.xtrace:
#log('+ %s -> %d', argv, status)
pass
elif node.tag == command_e.Sentence:
if node.terminator.id == Id.Op_Semi:
# Don't check_errexit since this isn't a real node!
check_errexit = False
status = self._Execute(node.child)
else:
status = self._RunJobInBackground(node.child)
elif node.tag == command_e.Pipeline:
if node.stderr_indices:
raise NotImplementedError('|&')
if node.negated:
self._PushErrExit()
try:
status2 = self._RunPipeline(node)
finally:
self._PopErrExit()
# errexit is disabled for !.
check_errexit = False
status = 1 if status2 == 0 else 0
else:
status = self._RunPipeline(node)
elif node.tag == command_e.Subshell:
# This makes sure we don't waste a process if we'd launch one anyway.
p = self._MakeProcess(node.child)
status = p.Run(self.waiter)
elif node.tag == command_e.DBracket:
result = self.bool_ev.Eval(node.expr)
status = 0 if result else 1
elif node.tag == command_e.DParen:
i = self.arith_ev.Eval(node.child)
status = 0 if i != 0 else 1
elif node.tag == command_e.Assignment:
pairs = []
if node.keyword == Id.Assign_Local:
lookup_mode = scope.LocalOnly
flags = ()
elif node.keyword == Id.Assign_Declare:
# declare is like local, except it can also be used outside functions?
lookup_mode = scope.LocalOnly
# TODO: Respect flags. -r and -x matter, but -a and -A might be
# implicit in the RHS?
flags = ()
elif node.keyword == Id.Assign_Readonly:
lookup_mode = scope.Dynamic
flags = (var_flags.ReadOnly,)
elif node.keyword == Id.Assign_None: # mutate existing local or global
lookup_mode = scope.Dynamic
flags = ()
else:
# TODO: typeset, declare, etc. Those are dynamic though.
raise NotImplementedError(node.keyword)
for pair in node.pairs:
if pair.rhs:
# RHS can be a string or array.
val = self.ev.EvalWordToAny(pair.rhs)
assert isinstance(val, runtime.value), val
else:
# 'local x' is equivalent to local x=""
val = runtime.Str('')
if pair.op == assign_op.PlusEqual:
old_val, lval = expr_eval.EvalLhs(pair.lhs, self.arith_ev, self.mem,
self.exec_opts)
sig = (old_val.tag, val.tag)
if sig == (value_e.Str, value_e.Str):
val = runtime.Str(old_val.s + val.s)
elif sig == (value_e.Str, value_e.StrArray):
e_die("Can't append array to string")
elif sig == (value_e.StrArray, value_e.Str):
e_die("Can't append string to array")
elif sig == (value_e.StrArray, value_e.StrArray):
val = runtime.StrArray(old_val.strs + val.strs)
else:
lval = self._EvalLhs(pair.lhs)
#log('ASSIGNING %s -> %s', lval, val)
self.mem.SetVar(lval, val, flags, lookup_mode)
# TODO: This should be eval of RHS, unlike bash!
status = 0
elif node.tag == command_e.ControlFlow:
if node.arg_word: # Evaluate the argument
val = self.ev.EvalWordToString(node.arg_word)
assert val.tag == value_e.Str
arg = int(val.s) # They all take integers
else:
arg = 0 # return 0, break 0 levels, etc.
# NOTE: always raises so we don't set status.
raise _ControlFlow(node.token, arg)
# The only difference between these two is that CommandList has no
# redirects. We already took care of that above.
elif node.tag in (command_e.CommandList, command_e.BraceGroup):
status = self._ExecuteList(node.children)
elif node.tag == command_e.AndOr:
#print(node.children)
left, right = node.children
# This is everything except the last one.
self._PushErrExit()
try:
status = self._Execute(left)
finally:
self._PopErrExit()
if node.op_id == Id.Op_DPipe:
if status != 0:
status = self._Execute(right)
elif node.op_id == Id.Op_DAmp:
if status == 0:
status = self._Execute(right)
else:
raise AssertionError
elif node.tag in (command_e.While, command_e.Until):
# TODO: Compile this out?
if node.tag == command_e.While:
_DonePredicate = lambda status: status != 0
else:
_DonePredicate = lambda status: status == 0
status = 0
while True:
self._PushErrExit()
try:
cond_status = self._ExecuteList(node.cond)
finally:
self._PopErrExit()
done = cond_status != 0
if _DonePredicate(cond_status):
break
try:
status = self._Execute(node.body) # last one wins
except _ControlFlow as e:
if e.IsBreak():
status = 0
break
elif e.IsContinue():
status = 0
continue
else: # return needs to pop up more
raise
elif node.tag == command_e.ForEach:
iter_name = node.iter_name
if node.do_arg_iter:
iter_list = self.mem.GetArgv()
else:
words = braces.BraceExpandWords(node.iter_words)
iter_list = self.ev.EvalWordSequence(words)
# We need word splitting and so forth
# NOTE: This expands globs too. TODO: We should pass in a Globber()
# object.
status = 0 # in case we don't loop
for x in iter_list:
#log('> ForEach setting %r', x)
state.SetLocalString(self.mem, iter_name, x)
#log('<')
try:
status = self._Execute(node.body) # last one wins
except _ControlFlow as e:
if e.IsBreak():
status = 0
break
elif e.IsContinue():
status = 0
continue
else: # return needs to pop up more
raise
elif node.tag == command_e.ForExpr:
raise NotImplementedError(node.tag)
elif node.tag == command_e.DoGroup:
status = self._ExecuteList(node.children)
elif node.tag == command_e.FuncDef:
# NOTE: Would it make sense to evaluate the redirects BEFORE entering?
# It will save time on function calls.
self.funcs[node.name] = node
status = 0
elif node.tag == command_e.If:
done = False
for arm in node.arms:
self._PushErrExit()
try:
status = self._ExecuteList(arm.cond)
finally:
self._PopErrExit()
if status == 0:
status = self._ExecuteList(arm.action)
done = True
break
# TODO: The compiler should flatten this
if not done and node.else_action is not None:
status = self._ExecuteList(node.else_action)
elif node.tag == command_e.NoOp:
status = 0 # make it true
elif node.tag == command_e.Case:
val = self.ev.EvalWordToString(node.to_match)
to_match = val.s
status = 0 # If there are no arms, it should be zero?
done = False
for arm in node.arms:
for pat_word in arm.pat_list:
# NOTE: Is it OK that we're evaluating these as we go?
pat_val = self.ev.EvalWordToString(pat_word, do_fnmatch=True)
#log('Matching word %r against pattern %r', to_match, pat_val.s)
if libc.fnmatch(pat_val.s, to_match):
status = self._ExecuteList(arm.action)
done = True # TODO: Parse ;;& and for fallthrough and such?
if done:
break
elif node.tag == command_e.TimeBlock:
# TODO:
# - When do we need RUSAGE_CHILDREN?
# - Respect TIMEFORMAT environment variable.
# "If this variable is not set, Bash acts as if it had the value"
# $'\nreal\t%3lR\nuser\t%3lU\nsys\t%3lS'
# "A trailing newline is added when the format string is displayed."
start_t = time.time() # calls gettimeofday() under the hood
start_u = resource.getrusage(resource.RUSAGE_SELF)
status = self._Execute(node.pipeline)
end_t = time.time()
end_u = resource.getrusage(resource.RUSAGE_SELF)
real = end_t - start_t
user = end_u.ru_utime - start_u.ru_utime
sys_ = end_u.ru_stime - start_u.ru_stime
print('real\t%.3f' % real, file=sys.stderr)
print('user\t%.3f' % user, file=sys.stderr)
print('sys\t%.3f' % sys_, file=sys.stderr)
else:
raise AssertionError(node.tag)
return status, check_errexit
def _EvalBracedVarSub(self, part, quoted):
"""
Returns:
part_value[]
"""
# We have four types of operator that interact.
#
# 1. Bracket: value -> (value, bool decay_array)
#
# 2. Then these four cases are mutually exclusive:
#
# a. Prefix length: value -> value
# b. Test: value -> part_value[]
# c. Other Suffix: value -> value
# d. no operator: you have a value
#
# That is, we don't have both prefix and suffix operators.
#
# 3. Process decay_array here before returning.
decay_array = False # for $*, ${a[*]}, etc.
var_name = None # For ${foo=default}
# 1. Evaluate from (var_name, var_num, token Id) -> value
if part.token.id == Id.VSub_Name:
var_name = part.token.val
val = self.mem.GetVar(var_name)
#log('EVAL NAME %s -> %s', var_name, val)
elif part.token.id == Id.VSub_Number:
var_num = int(part.token.val)
val = self._EvalVarNum(var_num)
else:
# $* decays
val, decay_array = self._EvalSpecialVar(part.token.id, quoted)
# 2. Bracket: value -> (value v, bool decay_array)
# decay_array is for joining ${a[*]} and unquoted ${a[@]} AFTER suffix ops
# are applied. If we take the length with a prefix op, the distinction is
# ignored.
if part.bracket_op:
if part.bracket_op.tag == bracket_op_e.WholeArray:
op_id = part.bracket_op.op_id
if op_id == Id.Lit_At:
if not quoted:
decay_array = True # ${a[@]} decays but "${a[@]}" doesn't
if val.tag == value_e.Undef:
val = self._EmptyStrArrayOrError(part.token)
elif val.tag == value_e.Str:
raise RuntimeError("Can't index string with @")
elif val.tag == value_e.StrArray:
val = runtime.StrArray(val.strs)
elif op_id == Id.Arith_Star:
decay_array = True # both ${a[*]} and "${a[*]}" decay
if val.tag == value_e.Undef:
val = self._EmptyStrArrayOrError(part.token)
elif val.tag == value_e.Str:
raise RuntimeError("Can't index string with *")
elif val.tag == value_e.StrArray:
# Always decay_array with ${a[*]} or "${a[*]}"
val = runtime.StrArray(val.strs)
else:
raise AssertionError(op_id) # unknown
elif part.bracket_op.tag == bracket_op_e.ArrayIndex:
anode = part.bracket_op.expr
index = self.arith_ev.Eval(anode)
if val.tag == value_e.Undef:
pass # it will be checked later
elif val.tag == value_e.Str:
# TODO: Implement this as an extension. Requires unicode support.
# Bash treats it as an array.
e_die("Can't index string %r with integer", part.token.val)
elif val.tag == value_e.StrArray:
try:
s = val.strs[index]
except IndexError:
val = runtime.Undef()
else:
val = runtime.Str(s)
else:
raise AssertionError(part.bracket_op.tag)
if part.prefix_op:
val = self._EmptyStrOrError(val) # maybe error
val = self._ApplyPrefixOp(val, part.prefix_op)
# At least for length, we can't have a test or suffix afterward.
elif part.suffix_op:
out_part_vals = []
op = part.suffix_op
if op.tag == suffix_op_e.StringUnary:
if LookupKind(part.suffix_op.op_id) == Kind.VTest:
# VTest: value -> part_value[]
new_part_vals, effect = self._ApplyTestOp(
val, part.suffix_op, quoted)
# NOTE: Splicing part_values is necessary because of code like
# ${undef:-'a b' c 'd # e'}. Each part_value can have a different
# do_glob/do_elide setting.
if effect == Effect.SpliceParts:
return new_part_vals # EARLY RETURN
elif effect == Effect.SpliceAndAssign:
if var_name is None:
# TODO: error context
e_die("Can't assign to special variable")
else:
# NOTE: This decays arrays too! 'set -o strict_array' could
# avoid it.
rhs_str = _DecayPartValuesToString(
new_part_vals, _GetJoinChar(self.mem))
state.SetLocalString(self.mem, var_name, rhs_str)
return new_part_vals
elif effect == Effect.Error:
raise NotImplementedError
else:
# The old one
#val = self._EmptyStringPartOrError(part_val, quoted)
#out_part_vals.append(part_val)
pass # do nothing, may still be undefined
else:
val = self._EmptyStrOrError(val) # maybe error
# Other suffix: value -> value
val = self._ApplyUnarySuffixOp(val, part.suffix_op)
elif op.tag == suffix_op_e.PatSub: # PatSub, vectorized
pat_val = self.word_ev.EvalWordToString(op.pat,
do_fnmatch=True)
assert pat_val.tag == value_e.Str, pat_val
if op.replace:
replace_val = self.word_ev.EvalWordToString(
op.replace, do_fnmatch=True)
assert replace_val.tag == value_e.Str, replace_val
replace_str = replace_val.s
else:
replace_str = ''
pat = pat_val.s
if val.tag == value_e.Str:
s = self._PatSub(val.s, op, pat, replace_str)
val = runtime.Str(s)
elif val.tag == value_e.StrArray:
strs = []
for s in val.strs:
strs.append(self._PatSub(s, op, pat, replace_str))
val = runtime.StrArray(strs)
else:
raise AssertionError(val.tag)
elif op.tag == suffix_op_e.Slice:
# Either string slicing or array slicing. However string slicing has
# a unicode problem?
# Or maybe have a different operator for byte slice and char slice.
raise NotImplementedError(op)
# After applying suffixes, process decay_array here.
if decay_array:
val = self._DecayArray(val)
# No prefix or suffix ops
val = self._EmptyStrOrError(val)
return [_ValueToPartValue(val, quoted)]
