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Bash chain

This notebook showcases using LLMs and a bash process to perform simple filesystem commands.

from langchain.chains import LLMBashChain
from langchain.llms import OpenAI

llm = OpenAI(temperature=0)

text = "Please write a bash script that prints 'Hello World' to the console."

bash_chain = LLMBashChain.from_llm(llm, verbose=True)

bash_chain.run(text)

API Reference:

    
    
    > Entering new LLMBashChain chain...
    Please write a bash script that prints 'Hello World' to the console.
    
    ```bash
    echo "Hello World"
    ```
    Code: ['echo "Hello World"']
    Answer: Hello World
    
    > Finished chain.





    'Hello World\n'

Customize Prompt​

You can also customize the prompt that is used. Here is an example prompting to avoid using the 'echo' utility

from langchain.prompts.prompt import PromptTemplate
from langchain.chains.llm_bash.prompt import BashOutputParser

_PROMPT_TEMPLATE = """If someone asks you to perform a task, your job is to come up with a series of bash commands that will perform the task. There is no need to put "#!/bin/bash" in your answer. Make sure to reason step by step, using this format:
Question: "copy the files in the directory named 'target' into a new directory at the same level as target called 'myNewDirectory'"
I need to take the following actions:
- List all files in the directory
- Create a new directory
- Copy the files from the first directory into the second directory
```bash
ls
mkdir myNewDirectory
cp -r target/* myNewDirectory

API Reference:

Do not use 'echo' when writing the script.

That is the format. Begin! Question: {question}"""

PROMPT = PromptTemplate( input_variables=["question"], template=_PROMPT_TEMPLATE, output_parser=BashOutputParser(), )



```python
bash_chain = LLMBashChain.from_llm(llm, prompt=PROMPT, verbose=True)

text = "Please write a bash script that prints 'Hello World' to the console."

bash_chain.run(text)
    
    
    > Entering new LLMBashChain chain...
    Please write a bash script that prints 'Hello World' to the console.
    
    ```bash
    printf "Hello World\n"
    ```
    Code: ['printf "Hello World\\n"']
    Answer: Hello World
    
    > Finished chain.





    'Hello World\n'

Persistent Terminal​

By default, the chain will run in a separate subprocess each time it is called. This behavior can be changed by instantiating with a persistent bash process.

from langchain.utilities.bash import BashProcess


persistent_process = BashProcess(persistent=True)
bash_chain = LLMBashChain.from_llm(llm, bash_process=persistent_process, verbose=True)

text = "List the current directory then move up a level."

bash_chain.run(text)

API Reference:

    
    
    > Entering new LLMBashChain chain...
    List the current directory then move up a level.
    
    ```bash
    ls
    cd ..
    ```
    Code: ['ls', 'cd ..']
    Answer: api.html            llm_summarization_checker.html
    constitutional_chain.html   moderation.html
    llm_bash.html           openai_openapi.yaml
    llm_checker.html        openapi.html
    llm_math.html           pal.html
    llm_requests.html       sqlite.html
    > Finished chain.





    'api.html\t\t\tllm_summarization_checker.html\r\nconstitutional_chain.html\tmoderation.html\r\nllm_bash.html\t\t\topenai_openapi.yaml\r\nllm_checker.html\t\topenapi.html\r\nllm_math.html\t\t\tpal.html\r\nllm_requests.html\t\tsqlite.html'
# Run the same command again and see that the state is maintained between calls
bash_chain.run(text)
    
    
    > Entering new LLMBashChain chain...
    List the current directory then move up a level.
    
    ```bash
    ls
    cd ..
    ```
    Code: ['ls', 'cd ..']
    Answer: examples        getting_started.html    index_examples
    generic         how_to_guides.rst
    > Finished chain.





    'examples\t\tgetting_started.html\tindex_examples\r\ngeneric\t\t\thow_to_guides.rst'