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.
type Plugin struct { // contains filtered or unexported fields}Plugin is a loaded Go plugin.
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 (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 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"