// Copyright 2016 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. // Package plugin implements loading and symbol resolution of Go plugins. // // 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. // // Currently plugins are only supported on Linux, FreeBSD, and macOS. // Please report any issues. package plugin // Plugin is a loaded Go plugin. type Plugin struct { pluginpath string err string // set if plugin failed to load loaded chan struct{} // closed when loaded syms map[string]interface{} } // 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 Open(path string) (*Plugin, error) { return open(path) } // 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. func (p *Plugin) Lookup(symName string) (Symbol, error) { return lookup(p, symName) } // A Symbol is a pointer to a variable or function. // // For example, a plugin defined as // // package main // // 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" type Symbol interface{}