def Eval(self, node):
# type: (command_t) -> None
UP_node = node
with tagswitch(node) as case:
if case(command_e.Simple):
node = cast(command__Simple, UP_node)
# Need splitter for this.
if 0:
cmd_val = self.word_ev.EvalWordSequence2(node.words,
allow_assign=True)
for arg in cmd_val.argv:
log('arg %s', arg)
for w in node.words:
val = self.word_ev.EvalWordToString(w)
# TODO: how to print repr() in C++?
log('arg %d', val.tag_())
elif case(command_e.DParen):
node = cast(command__DParen, UP_node)
a = self.arith_ev.Eval(node.child)
# TODO: how to print repr() in C++?
log('arith val %d', a.tag_())
else:
log('Unhandled node %s', NewStr(command_str(node.tag_())))
def RunCommandSub(self, node):
# type: (command_t) -> str
# Hack for weird $(<file) construct
if node.tag_() == command_e.Simple:
simple = cast(command__Simple, node)
# Detect '< file'
if (len(simple.words) == 0 and len(simple.redirects) == 1
and simple.redirects[0].op.id == Id.Redir_Less):
# change it to __cat < file
# note: cmd_eval.py _Dispatch works around lack of spid
tok = Token(Id.Lit_Chars, runtime.NO_SPID, '__cat')
cat_word = compound_word([tok])
# MUTATE the command.Simple node. This will only be done the first
# time in the parent process.
simple.words.append(cat_word)
p = self._MakeProcess(node,
inherit_errexit=self.exec_opts.inherit_errexit())
r, w = posix.pipe()
p.AddStateChange(process.StdoutToPipe(r, w))
_ = p.Start()
#log('Command sub started %d', pid)
chunks = [] # type: List[str]
posix.close(w) # not going to write
while True:
byte_str = posix.read(r, 4096)
if len(byte_str) == 0:
break
chunks.append(byte_str)
posix.close(r)
status = p.Wait(self.waiter)
# OSH has the concept of aborting in the middle of a WORD. We're not
# waiting until the command is over!
if self.exec_opts.more_errexit():
if self.exec_opts.errexit() and status != 0:
raise error.ErrExit('Command sub exited with status %d (%r)',
status, NewStr(command_str(node.tag_())))
else:
# Set a flag so we check errexit at the same time as bash. Example:
#
# a=$(false)
# echo foo # no matter what comes here, the flag is reset
#
# Set ONLY until this command node has finished executing.
# HACK: move this
self.cmd_ev.check_command_sub_status = True
self.mem.SetLastStatus(status)
# Runtime errors test case: # $("echo foo > $@")
# Why rstrip()?
# https://unix.stackexchange.com/questions/17747/why-does-shell-command-substitution-gobble-up-a-trailing-newline-char
return ''.join(chunks).rstrip('\n')
def CommandType(cmd):
# type: (command_t) -> str
"""For displaying commands in the UI."""
# Displays 'value.MaybeStrArray' for now, maybe change it.
return NewStr(command_str(cmd.tag_()))