Files
falyx/falyx/action/shell_action.py
2025-06-08 14:45:41 -04:00

106 lines
4.0 KiB
Python

# Falyx CLI Framework — (c) 2025 rtj.dev LLC — MIT Licensed
"""shell_action.py
Execute shell commands with input substitution."""
from __future__ import annotations
import shlex
import subprocess
import sys
from typing import Any, Callable
from rich.tree import Tree
from falyx.action.io_action import BaseIOAction
from falyx.exceptions import FalyxError
from falyx.themes import OneColors
class ShellAction(BaseIOAction):
"""
ShellAction wraps a shell command template for CLI pipelines.
This Action takes parsed input (from stdin, literal, or last_result),
substitutes it into the provided shell command template, and executes
the command asynchronously using subprocess.
Designed for quick integration with shell tools like `grep`, `ping`, `jq`, etc.
⚠️ Security Warning:
By default, ShellAction uses `shell=True`, which can be dangerous with
unsanitized input. To mitigate this, set `safe_mode=True` to use `shell=False`
with `shlex.split()`.
Features:
- Automatically handles input parsing (str/bytes)
- `safe_mode=True` disables shell interpretation and runs with `shell=False`
- Captures stdout and stderr from shell execution
- Raises on non-zero exit codes with stderr as the error
- Result is returned as trimmed stdout string
Args:
name (str): Name of the action.
command_template (str): Shell command to execute. Must include `{}` to include
input. If no placeholder is present, the input is not
included.
safe_mode (bool): If True, runs with `shell=False` using shlex parsing
(default: False).
"""
def __init__(
self, name: str, command_template: str, safe_mode: bool = False, **kwargs
):
super().__init__(name=name, **kwargs)
self.command_template = command_template
self.safe_mode = safe_mode
def from_input(self, raw: str | bytes) -> str:
if not isinstance(raw, (str, bytes)):
raise TypeError(
f"{self.name} expected str or bytes input, got {type(raw).__name__}"
)
return raw.strip() if isinstance(raw, str) else raw.decode("utf-8").strip()
def get_infer_target(self) -> tuple[Callable[..., Any] | None, dict[str, Any] | None]:
if sys.stdin.isatty():
return self._run, {"parsed_input": {"help": self.command_template}}
return None, None
async def _run(self, parsed_input: str) -> str:
# Replace placeholder in template, or use raw input as full command
command = self.command_template.format(parsed_input)
if self.safe_mode:
try:
args = shlex.split(command)
except ValueError as error:
raise FalyxError(f"Invalid command template: {error}")
result = subprocess.run(args, capture_output=True, text=True, check=True)
else:
result = subprocess.run(
command, shell=True, text=True, capture_output=True, check=True
)
if result.returncode != 0:
raise RuntimeError(result.stderr.strip())
return result.stdout.strip()
def to_output(self, result: str) -> str:
return result
async def preview(self, parent: Tree | None = None):
label = [f"[{OneColors.GREEN_b}]⚙ ShellAction[/] '{self.name}'"]
label.append(f"\n[dim]Template:[/] {self.command_template}")
label.append(
f"\n[dim]Safe mode:[/] {'Enabled' if self.safe_mode else 'Disabled'}"
)
if self.inject_last_result:
label.append(f" [dim](injects '{self.inject_into}')[/dim]")
tree = parent.add("".join(label)) if parent else Tree("".join(label))
if not parent:
self.console.print(tree)
def __str__(self):
return (
f"ShellAction(name={self.name!r}, command_template={self.command_template!r},"
f" safe_mode={self.safe_mode})"
)