Shell (bash)

Giving agents access to the shell is powerful (though risky outside a sandboxed environment).

The LLM can use it to execute any shell commands. A common use case for this is letting the LLM interact with your local file system.

Note: Shell tool does not work with Windows OS.

from langchain_community.tools import ShellTool

shell_tool = ShellTool()

print(shell_tool.run({"commands": ["echo 'Hello World!'", "time"]}))

Hello World!

real    0m0.000s
user    0m0.000s
sys 0m0.000s
``````output
/Users/wfh/code/lc/lckg/langchain/tools/shell/tool.py:34: UserWarning: The shell tool has no safeguards by default. Use at your own risk.
  warnings.warn(

Use with Agents

As with all tools, these can be given to an agent to accomplish more complex tasks. Let's have the agent fetch some links from a web page.

from langchain.agents import AgentType, initialize_agent
from langchain_openai import ChatOpenAI

llm = ChatOpenAI(temperature=0)

shell_tool.description = shell_tool.description + f"args {shell_tool.args}".replace(
    "{", "{{"
).replace("}", "}}")
self_ask_with_search = initialize_agent(
    [shell_tool], llm, agent=AgentType.CHAT_ZERO_SHOT_REACT_DESCRIPTION, verbose=True
)
self_ask_with_search.run(
    "Download the langchain.com webpage and grep for all urls. Return only a sorted list of them. Be sure to use double quotes."
)

> Entering new AgentExecutor chain...
Question: What is the task?
Thought: We need to download the langchain.com webpage and extract all the URLs from it. Then we need to sort the URLs and return them.
Action:

{ "action": "shell", "action_input": { "commands": [ "curl -s https://langchain.com | grep -o 'http[s]://[^\" ]' | sort" ] } }


``````output
/Users/wfh/code/lc/lckg/langchain/tools/shell/tool.py:34: UserWarning: The shell tool has no safeguards by default. Use at your own risk.
  warnings.warn(
``````output

Observation: https://blog.langchain.dev/
https://discord.gg/6adMQxSpJS
https://docs.langchain.com/docs/
https://github.com/hwchase17/chat-langchain
https://github.com/hwchase17/langchain
https://github.com/hwchase17/langchainjs
https://github.com/sullivan-sean/chat-langchainjs
https://js.langchain.com/docs/
https://python.langchain.com/en/latest/
https://twitter.com/langchainai

Thought:The URLs have been successfully extracted and sorted. We can return the list of URLs as the final answer.
Final Answer: ["https://blog.langchain.dev/", "https://discord.gg/6adMQxSpJS", "https://docs.langchain.com/docs/", "https://github.com/hwchase17/chat-langchain", "https://github.com/hwchase17/langchain", "https://github.com/hwchase17/langchainjs", "https://github.com/sullivan-sean/chat-langchainjs", "https://js.langchain.com/docs/", "https://python.langchain.com/en/latest/", "https://twitter.com/langchainai"]

> Finished chain.

'["https://blog.langchain.dev/", "https://discord.gg/6adMQxSpJS", "https://docs.langchain.com/docs/", "https://github.com/hwchase17/chat-langchain", "https://github.com/hwchase17/langchain", "https://github.com/hwchase17/langchainjs", "https://github.com/sullivan-sean/chat-langchainjs", "https://js.langchain.com/docs/", "https://python.langchain.com/en/latest/", "https://twitter.com/langchainai"]'