I think it's quite optimistic to classify any file that starts with <?xml as an SVG file, and any file that starts with #define\s as an XBM file. I've many files on my system that match one of the patterns, and are neither SVG or XBM files.

I would use the (external) commands file (standard Unix tool) and/or identify (from the ImageMagick suite) to determine file types.

In reply to Re: How do I find the type of an image? by JavaFan
in thread How do I find the type of an image? by ahmad

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