langchain/utilities/bash.py/BashProcess/_run
class BashProcess:    def _run(self, command: str) -> str:
        """Run commands and return final output."""
        try:
            output = subprocess.run(
                command,
                shell=True,
                check=True,
                stdout=subprocess.PIPE,
                stderr=subprocess.STDOUT,
            ).stdout.decode()
        except subprocess.CalledProcessError as error:
            if self.return_err_output:
                return error.stdout.decode()
            return str(error)
        if self.strip_newlines:
            output = output.strip()
        return output