The plugin package
- Go course
- Advanced
- Lesson 19/68
- 4 min
Learn the basics and limits of the plugin package.
The plugin package
The plugin package lets you load separately compiled Go code (a .so file) at run time and use its functions and variables. It is a way to add features without rebuilding the main program.
p, err := plugin.Open("selam.so")
sym, err := p.Lookup("Selam")It only works on Linux, FreeBSD and macOS; Windows is not supported.
Limitations
A plugin and the main program must be built with the same Go version and the same dependency versions, or loading fails. A loaded plugin can never be unloaded. That is why many projects prefer systems that talk to separate processes (e.g. HashiCorp go-plugin, gRPC) instead.
Practice Load a plugin
Call plugin.Open("selam.so"). If there is an error print fmt.Println("yüklenemedi") and return; otherwise print fmt.Println("yüklendi"). (The file doesn't exist here, so the output is yüklenemedi.)
Starter code
package main
import (
"fmt"
"plugin"
)
func main() {
// buraya yaz
}Sample solution
package main
import (
"fmt"
"plugin"
)
func main() {
_, err := plugin.Open("selam.so")
if err != nil {
fmt.Println("yüklenemedi")
return
}
fmt.Println("yüklendi")
}Expected output
yüklenemedi
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 On which system does the plugin package <strong>not</strong> work?
- macOS
- FreeBSD
- Windows Correct answer
- Linux
Explanation: Go plugin support is only for Linux, FreeBSD and macOS; on Windows plugin.Open returns an error.
2 Open a plugin
p, err := plugin.____("eklenti.so")p, err := plugin.Open("eklenti.so")Explanation: plugin.Open loads the .so file and returns a *plugin.Plugin.
3 plugin concepts
| Term | Meaning |
|---|---|
.so file |
Compiled plugin |
plugin.Open |
Loading |
Lookup |
Symbol lookup |
Same Go version |
Compatibility requirement |