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diff --git a/contrib/file/magic.man b/contrib/file/magic.man deleted file mode 100644 index 55ad4a4f3059..000000000000 --- a/contrib/file/magic.man +++ /dev/null @@ -1,215 +0,0 @@ -.TH MAGIC __FSECTION__ "Public Domain" -.\" install as magic.4 on USG, magic.5 on V7 or Berkeley systems. -.SH NAME -magic \- file command's magic number file -.SH DESCRIPTION -This manual page documents the format of the magic file as -used by the -.BR file (__CSECTION__) -command, version __VERSION__. The -.B file -command identifies the type of a file using, -among other tests, -a test for whether the file begins with a certain -.IR "magic number" . -The file -.I __MAGIC__ -specifies what magic numbers are to be tested for, -what message to print if a particular magic number is found, -and additional information to extract from the file. -.PP -Each line of the file specifies a test to be performed. -A test compares the data starting at a particular offset -in the file with a 1-byte, 2-byte, or 4-byte numeric value or -a string. If the test succeeds, a message is printed. -The line consists of the following fields: -.IP offset \w'message'u+2n -A number specifying the offset, in bytes, into the file of the data -which is to be tested. -.IP type -The type of the data to be tested. The possible values are: -.RS -.IP byte \w'message'u+2n -A one-byte value. -.IP short -A two-byte value (on most systems) in this machine's native byte order. -.IP long -A four-byte value (on most systems) in this machine's native byte order. -.IP string -A string of bytes. The string type specification can be optionally followed -by /[Bbc]*. The ``B'' flag compacts whitespace in the target, which must -contain at least one whitespace character. If the magic has "n" consecutive -blanks, the target needs at least "n" consecutive blanks to match. The ``b'' -flag treats every blank in the target as an optional blank. Finally the ``c'' -flag, specifies case insensitive matching: lowercase characters in the magic -match both lower and upper case characters in the targer, whereas upper case -characters in the magic, only much uppercase characters in the target. -.IP date -A four-byte value interpreted as a unix date. -.IP beshort -A two-byte value (on most systems) in big-endian byte order. -.IP belong -A four-byte value (on most systems) in big-endian byte order. -.IP bedate -A four-byte value (on most systems) in big-endian byte order, -interpreted as a unix date. -.IP leshort -A two-byte value (on most systems) in little-endian byte order. -.IP lelong -A four-byte value (on most systems) in little-endian byte order. -.IP ledate -A four-byte value (on most systems) in little-endian byte order, -interpreted as a unix date. -.RE -.PP -The numeric types may optionally be followed by -.B & -and a numeric value, -to specify that the value is to be AND'ed with the -numeric value before any comparisons are done. Prepending a -.B u -to the type indicates that ordered comparisons should be unsigned. -.IP test -The value to be compared with the value from the file. If the type is -numeric, this value -is specified in C form; if it is a string, it is specified as a C string -with the usual escapes permitted (e.g. \en for new-line). -.IP -Numeric values -may be preceded by a character indicating the operation to be performed. -It may be -.BR = , -to specify that the value from the file must equal the specified value, -.BR < , -to specify that the value from the file must be less than the specified -value, -.BR > , -to specify that the value from the file must be greater than the specified -value, -.BR & , -to specify that the value from the file must have set all of the bits -that are set in the specified value, -.BR ^ , -to specify that the value from the file must have clear any of the bits -that are set in the specified value, or -.BR x , -to specify that any value will match. If the character is omitted, -it is assumed to be -.BR = . -.IP -Numeric values are specified in C form; e.g. -.B 13 -is decimal, -.B 013 -is octal, and -.B 0x13 -is hexadecimal. -.IP -For string values, the byte string from the -file must match the specified byte string. -The operators -.BR = , -.B < -and -.B > -(but not -.BR & ) -can be applied to strings. -The length used for matching is that of the string argument -in the magic file. This means that a line can match any string, and -then presumably print that string, by doing -.B >\e0 -(because all strings are greater than the null string). -.IP message -The message to be printed if the comparison succeeds. If the string -contains a -.BR printf (3S) -format specification, the value from the file (with any specified masking -performed) is printed using the message as the format string. -.PP -Some file formats contain additional information which is to be printed -along with the file type. A line which begins with the character -.B > -indicates additional tests and messages to be printed. The number of -.B > -on the line indicates the level of the test; a line with no -.B > -at the beginning is considered to be at level 0. -Each line at level -.IB n \(pl1 -is under the control of the line at level -.IB n -most closely preceding it in the magic file. -If the test on a line at level -.I n -succeeds, the tests specified in all the subsequent lines at level -.IB n \(pl1 -are performed, and the messages printed if the tests succeed. The next -line at level -.I n -terminates this. -If the first character following the last -.B > -is a -.B ( -then the string after the parenthesis is interpreted as an indirect offset. -That means that the number after the parenthesis is used as an offset in -the file. The value at that offset is read, and is used again as an offset -in the file. Indirect offsets are of the form: -.BI (( x [.[bslBSL]][+-][ y ]). -The value of -.I x -is used as an offset in the file. A byte, short or long is read at that offset -depending on the -.B [bslBSL] -type specifier. The capitalized types interpret the number as a big endian -value, whereas the small letter versions interpet the number as a little -endian value. To that number the value of -.I y -is added and the result is used as an offset in the file. The default type -if one is not specified is long. -.PP -Sometimes you do not know the exact offset as this depends on the length of -preceding fields. You can specify an offset relative to the end of the -last uplevel field (of course this may only be done for sublevel tests, i.e. -test beginning with -.B > -). Such a relative offset is specified using -.B & -as a prefix to the offset. -.SH BUGS -The formats -.IR long , -.IR belong , -.IR lelong , -.IR short , -.IR beshort , -.IR leshort , -.IR date , -.IR bedate , -and -.I ledate -are system-dependent; perhaps they should be specified as a number -of bytes (2B, 4B, etc), -since the files being recognized typically come from -a system on which the lengths are invariant. -.PP -There is (currently) no support for specified-endian data to be used in -indirect offsets. -.SH SEE ALSO -.BR file (__CSECTION__) -\- the command that reads this file. -.\" -.\" From: guy@sun.uucp (Guy Harris) -.\" Newsgroups: net.bugs.usg -.\" Subject: /etc/magic's format isn't well documented -.\" Message-ID: <2752@sun.uucp> -.\" Date: 3 Sep 85 08:19:07 GMT -.\" Organization: Sun Microsystems, Inc. -.\" Lines: 136 -.\" -.\" Here's a manual page for the format accepted by the "file" made by adding -.\" the changes I posted to the S5R2 version. -.\" -.\" Modified for Ian Darwin's version of the file command. -.\" @(#)$Id: magic.man,v 1.16 1999/11/28 20:02:29 christos Exp $ |