Glossary · Phase 7 · Software engineering
File signature
The fixed bytes at the start of a file format, such as 89 50 4E 47 for PNG, that show what a file really is whatever its name.
Try it now
Ignore the file name: only the first bytes count.
Learn it properly
Binary files · Bytes as numbers, endianness, struct records, file signatures and checking uploads. About 40 minutes.
Other terms from the same lesson
- endianness: Which end of a multi-byte number is stored first: the big part (big-endian) or the small part (little-endian).
- hexadecimal: Counting in sixteens, with digits 0 to 9 and a to f; two hex digits show one byte, from 00 to ff.
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