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package selfexe
import (
"crypto/sha256"
"encoding/hex"
"fmt"
"io"
"os"
"sync"
)
const Path = "/proc/self/exe"
type Pin struct {
Sha256 string
Size int64
}
var (
mu sync.Mutex
cached *Pin
)
func Sum() (Pin, error) {
mu.Lock()
defer mu.Unlock()
if cached != nil {
return *cached, nil
}
f, err := os.Open(Path)
if err != nil {
return Pin{}, fmt.Errorf("selfexe: %w", err)
}
defer f.Close()
h := sha256.New()
n, err := io.Copy(h, f)
if err != nil {
return Pin{}, fmt.Errorf("selfexe: hashing %s: %w", Path, err)
}
cached = &Pin{Sha256: hex.EncodeToString(h.Sum(nil)), Size: n}
return *cached, nil
}
