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-
- Find file types by using a modified "magic" file
-
- Based on file v3.22 by Ian F. Darwin (see libfile/LEGAL.NOTICE and
- libfile/README.dist - File v3.22 can be found at many archive sites)
-
- For each entry in the magic file, the "message" for the initial offset MUST
- be 4 characters for the CREATOR and 4 characters for the TYPE - white space is
- optional between them. Any other characters on this line are ignored.
- Continuation lines (starting with a '>') are also ignored i.e. only the initial
- offset lines are used.
-
- e.g magic entry for a GIF file:
-
- # off type test message
- #
- # GIF image
- 0 string GIF8 8BIM GIFf
- >4 string 7a \b, version 8%s,
- >4 string 9a \b, version 8%s,
- >6 leshort >0 %hd x
- >8 leshort >0 %hd,
- #>10 byte &0x80 color mapped,
- #>10 byte&0x07 =0x00 2 colors
- #>10 byte&0x07 =0x01 4 colors
- #>10 byte&0x07 =0x02 8 colors
- #>10 byte&0x07 =0x03 16 colors
- #>10 byte&0x07 =0x04 32 colors
- #>10 byte&0x07 =0x05 64 colors
- #>10 byte&0x07 =0x06 128 colors
- #>10 byte&0x07 =0x07 256 colors
-
- Just the "8BIM" "GIFf" will be used whatever the type of GIF file it is.
- The continuation lines are used by the "file" command, but ignored by
- mkhybrid. They could be left out completely.
-
- The complete format of the magic file is given in the magic man page (magic.5).
-
- See the file "magic" for other examples
-
- Use with the -magic magic_file option, where magic_file is a file
- described above.
-
- The magic file can be used with the mapping file (option -map) - the order
- these options appear on the command line is important. mkhybrid will try to
- detect if the file is one of the Unix/Mac files (e.g. a CAP or Netatalk
- file) first. If that fails, it will then use the magic and/or mapping
- file e.g:
-
- mkhybrid -o output.raw -map mapping -magic magic src_dir
-
- The above will check filename extensions first, if that fails to set the
- CREATOR/TYPE, the magic file will be used. To check the magic file
- before the filename extensions, use:
-
- mkhybrid -o output.raw -magic magic -map mapping src_dir
-
-
- Using just a magic file - filename extensions will not be checked e.g:
-
- mkhybrid -o output.raw -magic magic src_dir
-
- For the magic method to work, each file must be opened and read twice
- (once to find it's CREATOR/TYPE, and a second time to actually copy the
- file to the CD image). Therefore the -magic option may significantly
- increase processing time.
-
- If a file's CREATOR/TYPE is not set via the magic and mapping matches,
- then the file is given the default CREATOR/TYPE.
-