BashChain

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)

> 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
```

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())

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)

> Entering new LLMBashChain chain...
List the current directory then move up a level.

```bash
ls
cd ..
```
Code: ['ls', 'cd ..']
Answer: api.ipynb			llm_summarization_checker.ipynb
constitutional_chain.ipynb	moderation.ipynb
llm_bash.ipynb			openai_openapi.yaml
llm_checker.ipynb		openapi.ipynb
llm_math.ipynb			pal.ipynb
llm_requests.ipynb		sqlite.ipynb
> Finished chain.

'api.ipynb\t\t\tllm_summarization_checker.ipynb\r\nconstitutional_chain.ipynb\tmoderation.ipynb\r\nllm_bash.ipynb\t\t\topenai_openapi.yaml\r\nllm_checker.ipynb\t\topenapi.ipynb\r\nllm_math.ipynb\t\t\tpal.ipynb\r\nllm_requests.ipynb\t\tsqlite.ipynb'

# 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.ipynb	index_examples
generic			how_to_guides.rst
> Finished chain.

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