def invoke(myprog: drgn.Program, first_input: Iterable[drgn.Object],
line: str) -> Iterable[drgn.Object]:
"""
This function intends to integrate directly with the SDB REPL, such
that the REPL will pass in the user-specified line, and this
function is responsible for converting that string into the
appropriate pipeline of Command objects, and executing it.
"""
target.set_prog(myprog)
#
# Build the pipeline by constructing each of the commands we want to
# use and building a list of them. If a shell pipeline is constructed
# at the end save it shell_cmd.
#
shell_cmd = None
pipeline = []
for cmd, cmd_type in parser.tokenize(line):
if cmd_type == parser.ExpressionType.CMD:
name, *args = cmd
if name not in get_registered_commands():
raise CommandNotFoundError(name)
try:
pipeline.append(get_registered_commands()[name](args, name))
except SystemExit as cmd_exit:
#
# The passed in arguments to each command will be parsed in
# the command object's constructor. We use "argparse" to do
# the argument parsing, and when that detects an error, it
# will throw this exception. Rather than exiting the entire
# SDB session, we only abort this specific pipeline by raising
# a CommandArgumentsError.
#
raise CommandArgumentsError(name) from cmd_exit
else:
assert cmd_type == parser.ExpressionType.SHELL_CMD
shell_cmd = cmd
#
# If we have a !, redirect stdout to a shell process. This avoids
# having to have a custom printing function that we pass around and
# use everywhere. We'll fix stdout to point back to the normal stdout
# at the end.
#
if shell_cmd is not None:
shell_proc = subprocess.Popen(shell_cmd,
shell=True,
stdin=subprocess.PIPE,
encoding="utf-8")
old_stdout = sys.stdout
#
# The type ignore below is due to the following false positive:
# https://github.com/python/typeshed/issues/1229
#
sys.stdout = shell_proc.stdin # type: ignore[assignment]
try:
if pipeline:
pipeline[0].isfirst = True
pipeline[-1].islast = True
yield from execute_pipeline(first_input, pipeline)
if shell_cmd is not None:
shell_proc.stdin.flush()
shell_proc.stdin.close()
finally:
if shell_cmd is not None:
sys.stdout = old_stdout
shell_proc.wait()
def invoke(myprog: drgn.Program, first_input: Iterable[drgn.Object],
line: str) -> Iterable[drgn.Object]:
"""
This function intends to integrate directly with the SDB REPL, such
that the REPL will pass in the user-specified line, and this
function is responsible for converting that string into the
appropriate pipeline of Command objects, and executing it.
"""
# pylint: disable=too-many-locals
# pylint: disable=too-many-branches
# pylint: disable=too-many-statements
target.set_prog(myprog)
shell_cmd = None
# Parse the argument string. Each pipeline stage is delimited by
# a pipe character "|". If there is a "!" character detected, then
# pipe all the remaining outout into a subshell.
lexer = shlex.shlex(line, posix=False, punctuation_chars="|!")
lexer.wordchars += "();<>&[]"
all_tokens = list(lexer)
pipe_stages = []
tokens: List[str] = []
for num, token in enumerate(all_tokens):
if token == "|":
pipe_stages.append(" ".join(tokens))
tokens = []
elif token == "!":
pipe_stages.append(" ".join(tokens))
if any(t == "!" for t in all_tokens[num + 1:]):
print("Multiple ! not supported")
return
shell_cmd = " ".join(all_tokens[num + 1:])
break
else:
tokens.append(token)
else:
# We didn't find a !, so all remaining tokens are part of
# the last pipe
pipe_stages.append(" ".join(tokens))
# Build the pipeline by constructing each of the commands we want to
# use and building a list of them.
pipeline = []
for stage in pipe_stages:
(name, _, args) = stage.strip().partition(" ")
if name not in get_registered_commands():
raise CommandNotFoundError(name)
try:
pipeline.append(get_registered_commands()[name](args, name))
except SystemExit:
# The passed in arguments to each command will be parsed in
# the command object's constructor. We use "argparse" to do
# the argument parsing, and when that detects an error, it
# will throw this exception. Rather than exiting the entire
# SDB session, we only abort this specific pipeline by raising
# a CommandArgumentsError.
raise CommandArgumentsError(name)
pipeline[-1].islast = True
# If we have a !, redirect stdout to a shell process. This avoids
# having to have a custom printing function that we pass around and
# use everywhere. We'll fix stdout to point back to the normal stdout
# at the end.
if shell_cmd is not None:
shell_proc = subprocess.Popen(shell_cmd,
shell=True,
stdin=subprocess.PIPE,
encoding="utf-8")
old_stdout = sys.stdout
#
# The type ignore below is due to the following false positive:
# https://github.com/python/typeshed/issues/1229
#
sys.stdout = shell_proc.stdin # type: ignore[assignment]
try:
yield from execute_pipeline(first_input, pipeline)
if shell_cmd is not None:
shell_proc.stdin.flush()
shell_proc.stdin.close()
finally:
if shell_cmd is not None:
sys.stdout = old_stdout
shell_proc.wait()