How does Ubuntu know what file type a file without extension is?

Question

As the question goes, how does Ubuntu know what file type a file without extension is?

When I save a file as "Untitled Document" without any extension, how does it know? Same thing for video and music formats...

Each type of file have it is on bit arrangement so the type of file can be determined by this pattern
else

some metadata also helpful to detect file type

still ubuntu cant understand filetype of most of the files without extension — Tachyons, Feb 28 '12 at 19:10

score 36 · Accepted Answer · answered Feb 28 '12 at 19:19

36

Via "magic"

The file(1) command identifies the type of a file using, among other tests, a test for whether the file contains certain ''magic patterns''. The file /usr/share/misc/magic specifies what patterns are to be tested for, what message or MIME type to print if a particular pattern is found, and additional information to extract from the file.

http://linux.die.net/man/5/magic

http://linux.die.net/man/1/file

answered Feb 28 '12 at 19:19

Panther

102,067

4

Well you weren't kidding about the magic now were you Houdini. Thanks Amazing Zazen! – Luis Alvarado Feb 28 '12 at 19:21

How does Ubuntu know what file type a file without extension is?

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