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package magic
import "bytes"
var (
// Png matches a Portable Network Graphics file.
// https://www.w3.org/TR/PNG/
Png = prefix([]byte{0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A})
// Apng matches an Animated Portable Network Graphics file.
// https://wiki.mozilla.org/APNG_Specification
Apng = offset([]byte("acTL"), 37)
// Jpg matches a Joint Photographic Experts Group file.
Jpg = prefix([]byte{0xFF, 0xD8, 0xFF})
// Jp2 matches a JPEG 2000 Image file (ISO 15444-1).
Jp2 = jpeg2k([]byte{0x6a, 0x70, 0x32, 0x20})
// Jpx matches a JPEG 2000 Image file (ISO 15444-2).
Jpx = jpeg2k([]byte{0x6a, 0x70, 0x78, 0x20})
// Jpm matches a JPEG 2000 Image file (ISO 15444-6).
Jpm = jpeg2k([]byte{0x6a, 0x70, 0x6D, 0x20})
// Gif matches a Graphics Interchange Format file.
Gif = prefix([]byte("GIF87a"), []byte("GIF89a"))
// Bmp matches a bitmap image file.
Bmp = prefix([]byte{0x42, 0x4D})
// Ps matches a PostScript file.
Ps = prefix([]byte("%!PS-Adobe-"))
// Psd matches a Photoshop Document file.
Psd = prefix([]byte("8BPS"))
// Ico matches an ICO file.
Ico = prefix([]byte{0x00, 0x00, 0x01, 0x00}, []byte{0x00, 0x00, 0x02, 0x00})
// Icns matches an ICNS (Apple Icon Image format) file.
Icns = prefix([]byte("icns"))
// Tiff matches a Tagged Image File Format file.
Tiff = prefix([]byte{0x49, 0x49, 0x2A, 0x00}, []byte{0x4D, 0x4D, 0x00, 0x2A})
// Bpg matches a Better Portable Graphics file.
Bpg = prefix([]byte{0x42, 0x50, 0x47, 0xFB})
// Xcf matches GIMP image data.
Xcf = prefix([]byte("gimp xcf"))
// Pat matches GIMP pattern data.
Pat = offset([]byte("GPAT"), 20)
// Gbr matches GIMP brush data.
Gbr = offset([]byte("GIMP"), 20)
// Hdr matches Radiance HDR image.
// https://web.archive.org/web/20060913152809/http://local.wasp.uwa.edu.au/~pbourke/dataformats/pic/
Hdr = prefix([]byte("#?RADIANCE\n"))
// Xpm matches X PixMap image data.
Xpm = prefix([]byte{0x2F, 0x2A, 0x20, 0x58, 0x50, 0x4D, 0x20, 0x2A, 0x2F})
)
func jpeg2k(sig []byte) Detector {
return func(raw []byte, _ uint32) bool {
if len(raw) < 24 {
return false
}
if !bytes.Equal(raw[4:8], []byte{0x6A, 0x50, 0x20, 0x20}) &&
!bytes.Equal(raw[4:8], []byte{0x6A, 0x50, 0x32, 0x20}) {
return false
}
return bytes.Equal(raw[20:24], sig)
}
}
// Webp matches a WebP file.
func Webp(raw []byte, _ uint32) bool {
return len(raw) > 12 &&
bytes.Equal(raw[0:4], []byte("RIFF")) &&
bytes.Equal(raw[8:12], []byte{0x57, 0x45, 0x42, 0x50})
}
// Dwg matches a CAD drawing file.
func Dwg(raw []byte, _ uint32) bool {
if len(raw) < 6 || raw[0] != 0x41 || raw[1] != 0x43 {
return false
}
dwgVersions := [][]byte{
{0x31, 0x2E, 0x34, 0x30},
{0x31, 0x2E, 0x35, 0x30},
{0x32, 0x2E, 0x31, 0x30},
{0x31, 0x30, 0x30, 0x32},
{0x31, 0x30, 0x30, 0x33},
{0x31, 0x30, 0x30, 0x34},
{0x31, 0x30, 0x30, 0x36},
{0x31, 0x30, 0x30, 0x39},
{0x31, 0x30, 0x31, 0x32},
{0x31, 0x30, 0x31, 0x34},
{0x31, 0x30, 0x31, 0x35},
{0x31, 0x30, 0x31, 0x38},
{0x31, 0x30, 0x32, 0x31},
{0x31, 0x30, 0x32, 0x34},
{0x31, 0x30, 0x33, 0x32},
}
for _, d := range dwgVersions {
if bytes.Equal(raw[2:6], d) {
return true
}
}
return false
}
// Jxl matches JPEG XL image file.
func Jxl(raw []byte, _ uint32) bool {
return bytes.HasPrefix(raw, []byte{0xFF, 0x0A}) ||
bytes.HasPrefix(raw, []byte("\x00\x00\x00\x0cJXL\x20\x0d\x0a\x87\x0a"))
}
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