s2f3 s2f3
s2f3
/ golang-image-func
Last active
September 27, 2019 02:44
https://github.com/golang/go/issues/5050
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| func getFormat(file *os.File) (string) { | |
| bytes := make([]byte, 4) | |
| n, _ := file.ReadAt(bytes, 0) | |
| if n < 4 { return "" } | |
| if bytes[0] == 0x89 && bytes[1] == 0x50 && bytes[2] == 0x4E && bytes[3] == 0x47 { return "png" } | |
| if bytes[0] == 0xFF && bytes[1] == 0xD8 { return "jpg" } | |
| if bytes[0] == 0x47 && bytes[1] == 0x49 && bytes[2] == 0x46 && bytes[3] == 0x38 { return "gif" } | |
| if bytes[0] == 0x42 && bytes[1] == 0x4D { return "bmp" } | |
| return "" | |
| } |