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.
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.
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"