Small and dependency free Go package to infer file and MIME type checking the magic numbers signature.
For SVG file type checking, see go-is-svg package. Python port: filetype.py.
go get github.com/h2non/filetype
See Godoc reference.
package main
import (
"fmt"
"io/ioutil"
"github.com/h2non/filetype"
)
func main() {
buf, _ := ioutil.ReadFile("sample.jpg")
kind, _ := filetype.Match(buf)
if kind == filetype.Unknown {
fmt.Println("Unknown file type")
return
}
fmt.Printf("File type: %s. MIME: %s\n", kind.Extension, kind.MIME.Value)
}
package main
import (
"fmt"
"io/ioutil"
"github.com/h2non/filetype"
)
func main() {
buf, _ := ioutil.ReadFile("sample.jpg")
if filetype.IsImage(buf) {
fmt.Println("File is an image")
} else {
fmt.Println("Not an image")
}
}
package main
import (
"fmt"
"github.com/h2non/filetype"
)
func main() {
// Check if file is supported by extension
if filetype.IsSupported("jpg") {
fmt.Println("Extension supported")
} else {
fmt.Println("Extension not supported")
}
// Check if file is supported by extension
if filetype.IsMIMESupported("image/jpeg") {
fmt.Println("MIME type supported")
} else {
fmt.Println("MIME type not supported")
}
}
package main
import (
"fmt"
"os"
"github.com/h2non/filetype"
)
func main() {
// Open a file descriptor
file, _ := os.Open("movie.mp4")
// We only have to pass the file header = first 261 bytes
head := make([]byte, 261)
file.Read(head)
if filetype.IsImage(head) {
fmt.Println("File is an image")
} else {
fmt.Println("Not an image")
}
}
package main
import (
"fmt"
"github.com/h2non/filetype"
)
var fooType = filetype.NewType("foo", "foo/foo")
func fooMatcher(buf []byte) bool {
return len(buf) > 1 && buf[0] == 0x01 && buf[1] == 0x02
}
func main() {
// Register the new matcher and its type
filetype.AddMatcher(fooType, fooMatcher)
// Check if the new type is supported by extension
if filetype.IsSupported("foo") {
fmt.Println("New supported type: foo")
}
// Check if the new type is supported by MIME
if filetype.IsMIMESupported("foo/foo") {
fmt.Println("New supported MIME type: foo/foo")
}
// Try to match the file
fooFile := []byte{0x01, 0x02}
kind, _ := filetype.Match(fooFile)
if kind == filetype.Unknown {
fmt.Println("Unknown file type")
} else {
fmt.Printf("File type matched: %s\n", kind.Extension)
}
}
image/jpeg
image/png
image/gif
image/webp
image/x-canon-cr2
image/tiff
image/bmp
image/heif
image/vnd.ms-photo
image/vnd.adobe.photoshop
image/vnd.microsoft.icon
image/vnd.dwg
image/avif
video/mp4
video/x-m4v
video/x-matroska
video/webm
video/quicktime
video/x-msvideo
video/x-ms-wmv
video/mpeg
video/x-flv
video/3gpp
audio/midi
audio/mpeg
audio/mp4
audio/ogg
audio/x-flac
audio/x-wav
audio/amr
audio/aac
audio/x-aiff
application/epub+zip
application/zip
application/x-tar
application/vnd.rar
application/gzip
application/x-bzip2
application/x-7z-compressed
application/x-xz
application/zstd
application/pdf
application/vnd.microsoft.portable-executable
application/x-shockwave-flash
application/rtf
application/x-iso9660-image
application/octet-stream
application/postscript
application/vnd.sqlite3
application/x-nintendo-nes-rom
application/x-google-chrome-extension
application/vnd.ms-cab-compressed
application/vnd.debian.binary-package
application/x-unix-archive
application/x-compress
application/x-lzip
application/x-rpm
application/x-executable
application/dicom
application/msword
application/vnd.openxmlformats-officedocument.wordprocessingml.document
application/vnd.ms-excel
application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
application/vnd.ms-powerpoint
application/vnd.openxmlformats-officedocument.presentationml.presentation
application/font-woff
application/font-woff
application/font-sfnt
application/font-sfnt
application/wasm
application/vnd.android.dex
application/vnd.android.dey
Measured using real files.
Environment: OSX x64 i7 2.7 Ghz
BenchmarkMatchTar-8 1000000 1083 ns/op
BenchmarkMatchZip-8 1000000 1162 ns/op
BenchmarkMatchJpeg-8 1000000 1280 ns/op
BenchmarkMatchGif-8 1000000 1315 ns/op
BenchmarkMatchPng-8 1000000 1121 ns/op
MIT - Tomas Aparicio