Go: plugin Index | Files

package plugin

import "plugin"

Package plugin implements loading and symbol resolution of Go plugins.

Currently plugins only work on Linux.

A plugin is a Go main package with exported functions and variables that has been built with:

go build -buildmode=plugin

When a plugin is first opened, the init functions of all packages not already part of the program are called. The main function is not run. A plugin is only initialized once, and cannot be closed.

Index

Package Files

plugin.go plugin_dlopen.go

type Plugin Uses

type Plugin struct {
    // contains filtered or unexported fields
}

Plugin is a loaded Go plugin.

func Open Uses

func Open(path string) (*Plugin, error)

Open opens a Go plugin. If a path has already been opened, then the existing *Plugin is returned. It is safe for concurrent use by multiple goroutines.

func (*Plugin) Lookup Uses

func (p *Plugin) Lookup(symName string) (Symbol, error)

Lookup searches for a symbol named symName in plugin p. A symbol is any exported variable or function. It reports an error if the symbol is not found. It is safe for concurrent use by multiple goroutines.

type Symbol Uses

type Symbol interface{}

A Symbol is a pointer to a variable or function.

For example, a plugin defined as

package main

// // No C code needed.
import "C"

import "fmt"

var V int

func F() { fmt.Printf("Hello, number %d\n", V) }

may be loaded with the Open function and then the exported package symbols V and F can be accessed

p, err := plugin.Open("plugin_name.so")
if err != nil {
	panic(err)
}
v, err := p.Lookup("V")
if err != nil {
	panic(err)
}
f, err := p.Lookup("F")
if err != nil {
	panic(err)
}
*v.(*int) = 7
f.(func())() // prints "Hello, number 7"

Package plugin imports 4 packages (graph) and is imported by 23 packages. Updated 2017-05-28. Refresh now. Tools for package owners.