Session and utilities
The file command
Guesses a file's real type by looking at its content, not its extension. Very useful when you do not know what it is.
Syntax
file archivo...Most useful options
-iShows the MIME type-bWithout the file name in frontCopy-ready examples
$ printf 'hola\n' > f.txt && file f.txtFile typeYou can try them in the browser terminal: it does not touch your computer.
Typical mistakes
- The extension does not matter: a .txt that is really an image is detected as an image.
FAQ
How does it know the type?
It reads the first bytes and compares them with known signatures (magic numbers).
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