Zapisanie tablicy bajtów do pliku binarnego

Mam tablicę bajtów w tej formie (jest to najprostszy obrazek jpg, w zasadzie same białe tło):

bytes = [255, 216, 255, 224, 0, 16, 74, 70, 73, 70, 0, 1, 1, 1, 0, 96, 0, 96, 0, 0, 255, 219, 0, 67, 0, 2, 1, 1, 2, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 5, 3, 3, 3, 3, 3, 6, 4, 4, 3, 5, 7, 6, 7, 7, 7, 6, 7, 7, 8, 9, 11, 9, 8, 8, 10, 8, 7, 7, 10, 13, 10, 10, 11, 12, 12, 12, 12, 7, 9, 14, 15, 13, 12, 14, 11, 12, 12, 12, 255, 219, 0, 67, 1, 2, 2, 2, 3, 3, 3, 6, 3, 3, 6, 12, 8, 7, 8, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 255, 192, 0, 17, 8, 0, 23, 0, 25, 3, 1, 34, 0, 2, 17, 1, 3, 17, 1, 255, 196, 0, 31, 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 255, 196, 0, 181, 16, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 125, 1, 2, 3, 0, 4, 17, 5, 18, 33, 49, 65, 6, 19, 81, 97, 7, 34, 113, 20, 50, 129, 145, 161, 8, 35, 66, 177, 193, 21, 82, 209, 240, 36, 51, 98, 114, 130, 9, 10, 22, 23, 24, 25, 26, 37, 38, 39, 40, 41, 42, 52, 53, 54, 55, 56, 57, 58, 67, 68, 69, 70, 71, 72, 73, 74, 83, 84, 85, 86, 87, 88, 89, 90, 99, 100, 101, 102, 103, 104, 105, 106, 115, 116, 117, 118, 119, 120, 121, 122, 131, 132, 133, 134, 135, 136, 137, 138, 146, 147, 148, 149, 150, 151, 152, 153, 154, 162, 163, 164, 165, 166, 167, 168, 169, 170, 178, 179, 180, 181, 182, 183, 184, 185, 186, 194, 195, 196, 197, 198, 199, 200, 201, 202, 210, 211, 212, 213, 214, 215, 216, 217, 218, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 255, 196, 0, 31, 1, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 255, 196, 0, 181, 17, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 119, 0, 1, 2, 3, 17, 4, 5, 33, 49, 6, 18, 65, 81, 7, 97, 113, 19, 34, 50, 129, 8, 20, 66, 145, 161, 177, 193, 9, 35, 51, 82, 240, 21, 98, 114, 209, 10, 22, 36, 52, 225, 37, 241, 23, 24, 25, 26, 38, 39, 40, 41, 42, 53, 54, 55, 56, 57, 58, 67, 68, 69, 70, 71, 72, 73, 74, 83, 84, 85, 86, 87, 88, 89, 90, 99, 100, 101, 102, 103, 104, 105, 106, 115, 116, 117, 118, 119, 120, 121, 122, 130, 131, 132, 133, 134, 135, 136, 137, 138, 146, 147, 148, 149, 150, 151, 152, 153, 154, 162, 163, 164, 165, 166, 167, 168, 169, 170, 178, 179, 180, 181, 182, 183, 184, 185, 186, 194, 195, 196, 197, 198, 199, 200, 201, 202, 210, 211, 212, 213, 214, 215, 216, 217, 218, 226, 227, 228, 229, 230, 231, 232, 233, 234, 242, 243, 244, 245, 246, 247, 248, 249, 250, 255, 218, 0, 12, 3, 1, 0, 2, 17, 3, 17, 0, 63, 0, 253, 252, 162, 138, 40, 0, 162, 138, 40, 0, 162, 138, 40, 0, 162, 138, 40, 3, 255, 217]

Próbuję zapisać to do pliku:
File.write(“temporary_image_file.jpg”, bytes)

Ale pliku nie da się otworzyć, dostaje informacje że plik nie jest plikiem jpg.
Ktoś pomoże?

File.write('image.jpg', bytes.pack('C*'))

Array#pack

Dziękuję działa poza railsami, ale kiedy uruchamiam kod w kontekście rails (z pliku seeds.rb) jest inny problem

seeds.rb

File.write('image.jpg', bytes.pack('C*'))
rails db:seed

Encoding::UndefinedConversionError: “\xFF” from ASCII-8BIT to UTF-8

Mam projekt w rails 6.1.4.1, standardowa konfiguracja.

Spróbuj:

File.write('image.jpg', bytes.pack('C*'), mode: 'wb')
1 Like

Dziękuję, zadziałało.