Identifying IGWD frame files with the Unix `file` command

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Identifying IGWD frame files with the Unix `file` command

The Unix `file` command can identify files by their "magic numbers", a pattern of characters or digits in the first few bytes of the file. The presscription below allows you to identify IGWD frame files, along with the format and library version.
Last updated: 11 January 2008
Put the following in a file named ".magic" in your home directory and you will be able to use the Unix file command to identify IGWD frame files, and to show the format and library versions used to create the file.
# Magic # LIGO/Virgo etc. # Interferometric Gravitational Wave Detectors frame files # (see LIGO document T970130-F-E for full specification) 0 string IGWD\0 IGWD frame file, >5 byte x Fmt %d, >6 byte x Lib %d, >40 string x %s
This can also be added to a system "magic" file, such as /usr/share/file/magic, so that it can be used by all users on a system. See the man page for file(1) for details.
See LIGO document T970130-F-E for the full specification of the IGWD frame file format.

-- Eric Myers

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