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package magic
import (
"fmt"
"io/ioutil"
"os"
"path/filepath"
"strings"
"sync"
)
var magicFiles map[string]bool
var mutex sync.Mutex
func init() {
magicFiles = make(map[string]bool)
}
func compileToMgc(file string) {
cookie := Open(MAGIC_NONE)
defer Close(cookie)
Compile(cookie, file)
}
func compileMagicFiles(dir string, files []string) {
// for some reason libmagic puts compiled files in the current working dir
// instead of the dir of the source file, so switch to the source dir,
// compile, then switch back
pwd, err := os.Getwd()
if err != nil {
return
}
err = os.Chdir(dir)
if err != nil {
return
}
defer os.Chdir(pwd)
for _, f := range files {
compileToMgc(f)
}
}
/* Add a directory for libmagic to search for .mgc databases. */
func AddMagicDir(dir string) error {
var err error
dir, err = filepath.Abs(dir)
if err != nil {
return err
}
fi, err := os.Stat(dir)
if err != nil {
return err
}
if fi.IsDir() == false {
return fmt.Errorf("Not a directory: %s", dir)
}
// get list of .magic files that need to be compiled to .mgc
var srcFiles []string
files, err := ioutil.ReadDir(dir)
if err != nil {
return err
}
for _, fi = range files {
if filepath.Ext(fi.Name()) == ".magic" {
mgcSrc := filepath.Join(dir, fi.Name())
_, err := os.Stat(mgcSrc + ".mgc")
if err != nil {
srcFiles = append(srcFiles, mgcSrc)
}
}
}
// compile .magic files
if len(srcFiles) > 0 {
compileMagicFiles(dir, srcFiles)
}
files, err = ioutil.ReadDir(dir)
if err != nil {
return err
}
mutex.Lock()
for _, fi = range files {
if filepath.Ext(fi.Name()) == ".mgc" {
mgcFile := filepath.Join(dir, fi.Name())
magicFiles[mgcFile] = true
}
}
mutex.Unlock()
return nil
}
/* Get mimetype from a file. */
func MimeFromFile(path string) string {
cookie := Open(MAGIC_ERROR | MAGIC_MIME_TYPE)
defer Close(cookie)
mutex.Lock()
var mf []string
for f := range magicFiles {
mf = append(mf, f)
}
mutex.Unlock()
ret := Load(cookie, strings.Join(mf, ":"))
if ret != 0 {
return "application/octet-stream"
}
r := File(cookie, path)
return r
}
/* Get mimetype from a buffer. */
func MimeFromBytes(b []byte) string {
cookie := Open(MAGIC_ERROR | MAGIC_MIME_TYPE)
defer Close(cookie)
mutex.Lock()
var mf []string
for f := range magicFiles {
mf = append(mf, f)
}
mutex.Unlock()
ret := Load(cookie, strings.Join(mf, ":"))
if ret != 0 {
return "application/octet-stream"
}
r := Buffer(cookie, b)
return r
}
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