Implementation:Ollama Ollama XTools Bash

Knowledge Sources	Ollama
Domains	Agent Loop, Tool Execution
Last Updated	2025-02-15 00:00 GMT

Overview

Implements the bash shell command execution tool for the Ollama agent loop, running commands with timeout and output size limits.

Description

BashTool implements the Tool interface. Execute runs a bash command with a 60-second timeout using exec.CommandContext, capturing both stdout and stderr separately. Output is truncated to 50KB to prevent overwhelming the LLM context. Returns exit codes and timeout information as part of the output string rather than as errors, so the LLM can reason about failures. Provides a schema definition with a single required command parameter.

Usage

Registered as the "bash" tool in the agent tool registry. The primary mechanism by which the LLM agent can interact with the user's system.

Code Reference

Source Location

• Repository: Ollama
• File: x/tools/bash.go
• Lines: 1-114

Signature

const bashTimeout = 60 * time.Second
const maxOutputSize = 50000

type BashTool struct{}

func (b *BashTool) Name() string
func (b *BashTool) Description() string
func (b *BashTool) Schema() api.ToolFunction
func (b *BashTool) Execute(args map[string]any) (string, error)

Import

import "github.com/ollama/ollama/x/tools"

I/O Contract

Inputs

Name	Type	Required	Description
command	string	Yes	The bash command to execute

Outputs

Name	Type	Description
output	string	Combined stdout/stderr with exit code info
error	error	Non-nil only for execution setup failures

Usage Examples

tool := &tools.BashTool{}

output, err := tool.Execute(map[string]any{
    "command": "ls -la /tmp",
})
// output: "total 48\ndrwxrwxrwt 12 root root ..."

// Timeout handling
output, err = tool.Execute(map[string]any{
    "command": "sleep 120",
})
// output: "... Error: command timed out after 60 seconds"

Related Pages

• Principle:Ollama_Ollama_AgentArchitecture