elf-thumbnailer.py

#!/usr/bin/env python3

from argparse import ArgumentParser
from lief import ELF

def generate_thumbnail(size, infile, outfile):
    prog = ELF.parse(infile)
    if prog is None:
        raise ValueError("failed to parse input file: " + infile)

    section = prog.get_section(".icon")
    if section is None:
        raise ValueError("cannot find section `.icon' in file: " + infile)

    data = section.content
    if data[0:1] == b'<': # naive but sufficient guess
        from cairosvg import svg2png
        svg2png(bytestring=data, output_width=size, output_height=size, write_to=outfile)
    else:
        from PIL import Image
        from io import BytesIO
        with Image.open(BytesIO(data)) as img:
            img = img.resize((size, size))
            img.save(outfile, "PNG")

def main():
    parser = ArgumentParser(description=__doc__)
    parser.add_argument("size", help="size of desired thumbnail")
    parser.add_argument("infile", help="input file name (ELF)")
    parser.add_argument("outfile", help="output file name (PNG)")
    args = parser.parse_args()

    try:
        generate_thumbnail(args.size, args.infile, args.outfile)
    except Exception as error:
        print("error:", error)
        exit(1)

if __name__ == "__main__":
    main()