found all execs in all GOPATH/bin dirs

main.go

@@ -0,0 +1,98 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func main() {
+	log.SetFlags(log.Ldate | log.Ltime | log.Lshortfile)
+	binDirs := []string{}
+	for _, env := range os.Environ() {
+		if strings.HasPrefix(env, "GOPATH=") {
+			i := strings.Index(env, "=")
+			paths := filepath.SplitList(env[i+1:])
+			for _, path := range paths {
+				binDirs = append(binDirs, filepath.Join(path, "bin"))
+			}
+		}
+	}
+
+	files := map[string]os.FileInfo{}
+
+	for _, binDir := range binDirs {
+		fi, err := os.Stat(binDir)
+		if err != nil {
+			log.Printf("%+v", err)
+			continue
+		}
+		if !fi.IsDir() {
+			log.Printf("%s is not a directory!", binDir)
+			continue
+		}
+		dirInfo, err := ioutil.ReadDir(binDir)
+		if err != nil {
+			log.Printf("%+v", err)
+			continue
+		}
+		for _, di := range dirInfo {
+			files[filepath.Join(binDir, di.Name())] = di
+		}
+	}
+
+	execs := []string{}
+	buf := &bytes.Buffer{}
+	for name, _ := range files {
+		buf.Reset()
+		if !exists(name) {
+			log.Fatal("this should never happen: file we just found isn't there now")
+		}
+		if fi, err := os.Stat(name); fi.IsDir() {
+			if err != nil {
+				log.Fatal(err)
+			}
+			continue
+		}
+		fi, err := os.Open(name)
+		if err != nil {
+			log.Fatal(err)
+		}
+		lr := &io.LimitedReader{
+			R: fi,
+			N: 2,
+		}
+		_, err = io.Copy(buf, lr)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		execPatterns := [][]byte{
+			{0x7f, 0x45},
+			{0xcf, 0xfa},
+		}
+		for _, b := range execPatterns {
+			if bytes.Equal(buf.Bytes(), b) {
+				execs = append(execs, name)
+			}
+		}
+	}
+
+	for _, exec := range execs {
+		fmt.Println(exec)
+	}
+}
+
+func exists(path string) bool {
+	if _, err := os.Stat(path); err != nil {
+		return false
+	} else if os.IsNotExist(err) {
+		return false
+	}
+	return true
+}