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Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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+.\" $File: magic.man,v 1.101 2022/10/09 18:51:04 christos Exp $
+.Dd October 9, 2022
+.Dt MAGIC __FSECTION__
+.Os
+.\" install as magic.4 on USG, magic.5 on V7, Berkeley and Linux systems.
+.Sh NAME
+.Nm magic
+.Nd file command's magic pattern file
+.Sh DESCRIPTION
+This manual page documents the format of magic files as
+used by the
+.Xr file __CSECTION__
+command, version __VERSION__.
+The
+.Xr file __CSECTION__
+command identifies the type of a file using,
+among other tests,
+a test for whether the file contains certain
+.Dq "magic patterns" .
+The database of these
+.Dq "magic patterns"
+is usually located in a binary file in
+.Pa __MAGIC__.mgc
+or a directory of source text magic pattern fragment files in
+.Pa __MAGIC__ .
+The database 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.
+.Pp
+The format of the source fragment files that are used to build this database
+is as follows:
+Each line of a fragment file specifies a test to be performed.
+A test compares the data starting at a particular offset
+in the file with a byte value, a string or a numeric value.
+If the test succeeds, a message is printed.
+The line consists of the following fields:
+.Bl -tag -width ".Dv message"
+.It Dv offset
+A number specifying the offset (in bytes) into the file of the data
+which is to be tested.
+This offset can be a negative number if it is:
+.Bl -bullet  -compact
+.It
+The first direct offset of the magic entry (at continuation level 0),
+in which case it is interpreted an offset from end end of the file
+going backwards.
+This works only when a file descriptor to the file is available and it
+is a regular file.
+.It
+A continuation offset relative to the end of the last up-level field
+.Dv ( \*[Am] ) .
+.El
+.It Dv type
+The type of the data to be tested.
+The possible values are:
+.Bl -tag -width ".Dv lestring16"
+.It Dv byte
+A one-byte value.
+.It Dv short
+A two-byte value in this machine's native byte order.
+.It Dv long
+A four-byte value in this machine's native byte order.
+.It Dv quad
+An eight-byte value in this machine's native byte order.
+.It Dv float
+A 32-bit single precision IEEE floating point number in this machine's native byte order.
+.It Dv double
+A 64-bit double precision IEEE floating point number in this machine's native byte order.
+.It Dv string
+A string of bytes.
+The string type specification can be optionally followed by a /<width> 
+option and optionally followed by a set of flags /[bCcftTtWw]*.
+The width limits the number of characters to be copied.
+Zero means all characters.
+The following flags are supported:
+.Bl -tag -width B -compact -offset XXXX
+.It b
+Force binary file test.
+.It C
+Use upper case insensitive matching: upper case
+characters in the magic match both lower and upper case characters in the
+target, whereas lower case characters in the magic only match upper case
+characters in the target.
+.It c
+Use lower case insensitive matching: lower case
+characters in the magic match both lower and upper case characters in the
+target, whereas upper case characters in the magic only match upper case
+characters in the target.
+To do a complete case insensitive match, specify both
+.Dq c
+and
+.Dq C .
+.It f
+Require that the matched string is a full word, not a partial word match.
+.It T
+Trim the string, i.e. leading and trailing whitespace
+.It t
+Force text file test.
+.It W
+Compact whitespace in the target, which must
+contain at least one whitespace character.
+If the magic has
+.Dv n
+consecutive blanks, the target needs at least
+.Dv n
+consecutive blanks to match.
+.It w
+Treat every blank in the magic as an optional blank.
+is deleted before the string is printed.
+.El
+.It Dv pstring
+A Pascal-style string where the first byte/short/int is interpreted as the
+unsigned length.
+The length defaults to byte and can be specified as a modifier.
+The following modifiers are supported:
+.Bl -tag -width B -compact -offset XXXX
+.It B
+A byte length (default).
+.It H
+A 2 byte big endian length.
+.It h
+A 2 byte little endian length.
+.It L
+A 4 byte big endian length.
+.It l
+A 4 byte little endian length.
+.It J
+The length includes itself in its count.
+.El
+The string is not NUL terminated.
+.Dq J
+is used rather than the more
+valuable
+.Dq I
+because this type of length is a feature of the JPEG
+format.
+.It Dv date
+A four-byte value interpreted as a UNIX date.
+.It Dv qdate
+An eight-byte value interpreted as a UNIX date.
+.It Dv ldate
+A four-byte value interpreted as a UNIX-style date, but interpreted as
+local time rather than UTC.
+.It Dv qldate
+An eight-byte value interpreted as a UNIX-style date, but interpreted as
+local time rather than UTC.
+.It Dv qwdate
+An eight-byte value interpreted as a Windows-style date.
+.It Dv beid3
+A 32-bit ID3 length in big-endian byte order.
+.It Dv beshort
+A two-byte value in big-endian byte order.
+.It Dv belong
+A four-byte value in big-endian byte order.
+.It Dv bequad
+An eight-byte value in big-endian byte order.
+.It Dv befloat
+A 32-bit single precision IEEE floating point number in big-endian byte order.
+.It Dv bedouble
+A 64-bit double precision IEEE floating point number in big-endian byte order.
+.It Dv bedate
+A four-byte value in big-endian byte order,
+interpreted as a Unix date.
+.It Dv beqdate
+An eight-byte value in big-endian byte order,
+interpreted as a Unix date.
+.It Dv beldate
+A four-byte value in big-endian byte order,
+interpreted as a UNIX-style date, but interpreted as local time rather
+than UTC.
+.It Dv beqldate
+An eight-byte value in big-endian byte order,
+interpreted as a UNIX-style date, but interpreted as local time rather
+than UTC.
+.It Dv beqwdate
+An eight-byte value in big-endian byte order,
+interpreted as a Windows-style date.
+.It Dv bestring16
+A two-byte unicode (UCS16) string in big-endian byte order.
+.It Dv leid3
+A 32-bit ID3 length in little-endian byte order.
+.It Dv leshort
+A two-byte value in little-endian byte order.
+.It Dv lelong
+A four-byte value in little-endian byte order.
+.It Dv lequad
+An eight-byte value in little-endian byte order.
+.It Dv lefloat
+A 32-bit single precision IEEE floating point number in little-endian byte order.
+.It Dv ledouble
+A 64-bit double precision IEEE floating point number in little-endian byte order.
+.It Dv ledate
+A four-byte value in little-endian byte order,
+interpreted as a UNIX date.
+.It Dv leqdate
+An eight-byte value in little-endian byte order,
+interpreted as a UNIX date.
+.It Dv leldate
+A four-byte value in little-endian byte order,
+interpreted as a UNIX-style date, but interpreted as local time rather
+than UTC.
+.It Dv leqldate
+An eight-byte value in little-endian byte order,
+interpreted as a UNIX-style date, but interpreted as local time rather
+than UTC.
+.It Dv leqwdate
+An eight-byte value in little-endian byte order,
+interpreted as a Windows-style date.
+.It Dv lestring16
+A two-byte unicode (UCS16) string in little-endian byte order.
+.It Dv melong
+A four-byte value in middle-endian (PDP-11) byte order.
+.It Dv medate
+A four-byte value in middle-endian (PDP-11) byte order,
+interpreted as a UNIX date.
+.It Dv meldate
+A four-byte value in middle-endian (PDP-11) byte order,
+interpreted as a UNIX-style date, but interpreted as local time rather
+than UTC.
+.It Dv indirect
+Starting at the given offset, consult the magic database again.
+The offset of the
+.Dv indirect
+magic is by default absolute in the file, but one can specify
+.Dv /r
+to indicate that the offset is relative from the beginning of the entry.
+.It Dv name
+Define a
+.Dq named
+magic instance that can be called from another
+.Dv use
+magic entry, like a subroutine call.
+Named instance direct magic offsets are relative to the offset of the
+previous matched entry, but indirect offsets are relative to the beginning
+of the file as usual.
+Named magic entries always match.
+.It Dv use
+Recursively call the named magic starting from the current offset.
+If the name of the referenced begins with a
+.Dv ^
+then the endianness of the magic is switched; if the magic mentioned
+.Dv leshort
+for example,
+it is treated as
+.Dv beshort
+and vice versa.
+This is useful to avoid duplicating the rules for different endianness.
+.It Dv regex
+A regular expression match in extended POSIX regular expression syntax
+(like egrep).
+Regular expressions can take exponential time to process, and their
+performance is hard to predict, so their use is discouraged.
+When used in production environments, their performance
+should be carefully checked.
+The size of the string to search should also be limited by specifying
+.Dv /<length> ,
+to avoid performance issues scanning long files.
+The type specification can also be optionally followed by
+.Dv /[c][s][l] .
+The
+.Dq c
+flag makes the match case insensitive, while the
+.Dq s
+flag update the offset to the start offset of the match, rather than the end.
+The
+.Dq l
+modifier, changes the limit of length to mean number of lines instead of a
+byte count.
+Lines are delimited by the platforms native line delimiter.
+When a line count is specified, an implicit byte count also computed assuming
+each line is 80 characters long.
+If neither a byte or line count is specified, the search is limited automatically
+to 8KiB.
+.Dv ^
+and
+.Dv $
+match the beginning and end of individual lines, respectively,
+not beginning and end of file.
+.It Dv search
+A literal string search starting at the given offset.
+The same modifier flags can be used as for string patterns.
+The search expression must contain the range in the form
+.Dv /number,
+that is the number of positions at which the match will be
+attempted, starting from the start offset.
+This is suitable for
+searching larger binary expressions with variable offsets, using
+.Dv \e
+escapes for special characters.
+The order of modifier and number is not relevant.
+.It Dv default
+This is intended to be used with the test
+.Em x
+(which is always true) and it has no type.
+It matches when no other test at that continuation level has matched before.
+Clearing that matched tests for a continuation level, can be done using the
+.Dv clear
+test.
+.It Dv clear
+This test is always true and clears the match flag for that continuation level.
+It is intended to be used with the
+.Dv default
+test.
+.It Dv der
+Parse the file as a DER Certificate file.
+The test field is used as a der type that needs to be matched.
+The DER types are:
+.Dv eoc ,
+.Dv bool ,
+.Dv int ,
+.Dv bit_str ,
+.Dv octet_str ,
+.Dv null ,
+.Dv obj_id ,
+.Dv obj_desc ,
+.Dv ext ,
+.Dv real ,
+.Dv enum ,
+.Dv embed ,
+.Dv utf8_str ,
+.Dv rel_oid ,
+.Dv time ,
+.Dv res2 ,
+.Dv seq ,
+.Dv set ,
+.Dv num_str ,
+.Dv prt_str ,
+.Dv t61_str ,
+.Dv vid_str ,
+.Dv ia5_str ,
+.Dv utc_time ,
+.Dv gen_time ,
+.Dv gr_str ,
+.Dv vis_str ,
+.Dv gen_str ,
+.Dv univ_str ,
+.Dv char_str ,
+.Dv bmp_str ,
+.Dv date ,
+.Dv tod ,
+.Dv datetime ,
+.Dv duration ,
+.Dv oid-iri ,
+.Dv rel-oid-iri .
+These types can be followed by an optional numeric size, which indicates
+the field width in bytes.
+.It Dv guid
+A Globally Unique Identifier, parsed and printed as
+XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX.
+It's format is a string.
+.It Dv offset
+This is a quad value indicating the current offset of the file.
+It can be used to determine the size of the file or the magic buffer.
+For example the magic entries:
+.Bd -literal -offset indent
+-0	offset	x	this file is %lld bytes
+-0	offset	<=100	must be more than 100 \e
+    bytes and is only %lld
+.Ed
+.It Dv octal
+A string representing an octal number.
+.El
+.El
+.Pp
+For compatibility with the Single
+.Ux
+Standard, the type specifiers
+.Dv dC
+and
+.Dv d1
+are equivalent to
+.Dv byte ,
+the type specifiers
+.Dv uC
+and
+.Dv u1
+are equivalent to
+.Dv ubyte ,
+the type specifiers
+.Dv dS
+and
+.Dv d2
+are equivalent to
+.Dv short ,
+the type specifiers
+.Dv uS
+and
+.Dv u2
+are equivalent to
+.Dv ushort ,
+the type specifiers
+.Dv dI ,
+.Dv dL ,
+and
+.Dv d4
+are equivalent to
+.Dv long ,
+the type specifiers
+.Dv uI ,
+.Dv uL ,
+and
+.Dv u4
+are equivalent to
+.Dv ulong ,
+the type specifier
+.Dv d8
+is equivalent to
+.Dv quad ,
+the type specifier
+.Dv u8
+is equivalent to
+.Dv uquad ,
+and the type specifier
+.Dv s
+is equivalent to
+.Dv string .
+In addition, the type specifier
+.Dv dQ
+is equivalent to
+.Dv quad
+and the type specifier
+.Dv uQ
+is equivalent to
+.Dv uquad .
+.Pp
+Each top-level magic pattern (see below for an explanation of levels)
+is classified as text or binary according to the types used.
+Types
+.Dq regex
+and
+.Dq search
+are classified as text tests, unless non-printable characters are used
+in the pattern.
+All other tests are classified as binary.
+A top-level
+pattern is considered to be a test text when all its patterns are text
+patterns; otherwise, it is considered to be a binary pattern.
+When
+matching a file, binary patterns are tried first; if no match is
+found, and the file looks like text, then its encoding is determined
+and the text patterns are tried.
+.Pp
+The numeric types may optionally be followed by
+.Dv \*[Am]
+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
+.Dv u
+to the type indicates that ordered comparisons should be unsigned.
+.It Dv 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).
+.Pp
+Numeric values
+may be preceded by a character indicating the operation to be performed.
+It may be
+.Dv = ,
+to specify that the value from the file must equal the specified value,
+.Dv \*[Lt] ,
+to specify that the value from the file must be less than the specified
+value,
+.Dv \*[Gt] ,
+to specify that the value from the file must be greater than the specified
+value,
+.Dv \*[Am] ,
+to specify that the value from the file must have set all of the bits
+that are set in the specified value,
+.Dv ^ ,
+to specify that the value from the file must have clear any of the bits
+that are set in the specified value, or
+.Dv ~ ,
+the value specified after is negated before tested.
+.Dv x ,
+to specify that any value will match.
+If the character is omitted, it is assumed to be
+.Dv = .
+Operators
+.Dv \*[Am] ,
+.Dv ^ ,
+and
+.Dv ~
+don't work with floats and doubles.
+The operator
+.Dv !\&
+specifies that the line matches if the test does
+.Em not
+succeed.
+.Pp
+Numeric values are specified in C form; e.g.
+.Dv 13
+is decimal,
+.Dv 013
+is octal, and
+.Dv 0x13
+is hexadecimal.
+.Pp
+Numeric operations are not performed on date types, instead the numeric
+value is interpreted as an offset.
+.Pp
+For string values, the string from the
+file must match the specified string.
+The operators
+.Dv = ,
+.Dv \*[Lt]
+and
+.Dv \*[Gt]
+(but not
+.Dv \*[Am] )
+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 non-empty string (usually used to
+then print the string), with
+.Em \*[Gt]\e0
+(because all non-empty strings are greater than the empty string).
+.Pp
+Dates are treated as numerical values in the respective internal
+representation.
+.Pp
+The special test
+.Em x
+always evaluates to true.
+.It Dv message
+The message to be printed if the comparison succeeds.
+If the string contains a
+.Xr printf 3
+format specification, the value from the file (with any specified masking
+performed) is printed using the message as the format string.
+If the string begins with
+.Dq \eb ,
+the message printed is the remainder of the string with no whitespace
+added before it: multiple matches are normally separated by a single
+space.
+.El
+.Pp
+An APPLE 4+4 character APPLE creator and type can be specified as:
+.Bd -literal -offset indent
+!:apple	CREATYPE
+.Ed
+.Pp
+A MIME type is given on a separate line, which must be the next
+non-blank or comment line after the magic line that identifies the
+file type, and has the following format:
+.Bd -literal -offset indent
+!:mime	MIMETYPE
+.Ed
+.Pp
+i.e. the literal string
+.Dq !:mime
+followed by the MIME type.
+.Pp
+An optional strength can be supplied on a separate line which refers to
+the current magic description using the following format:
+.Bd -literal -offset indent
+!:strength OP VALUE
+.Ed
+.Pp
+The operand
+.Dv OP
+can be:
+.Dv + ,
+.Dv - ,
+.Dv * ,
+or
+.Dv /
+and
+.Dv VALUE
+is a constant between 0 and 255.
+This constant is applied using the specified operand
+to the currently computed default magic strength.
+.Pp
+Some file formats contain additional information which is to be printed
+along with the file type or need additional tests to determine the true
+file type.
+These additional tests are introduced by one or more
+.Em \*[Gt]
+characters preceding the offset.
+The number of
+.Em \*[Gt]
+on the line indicates the level of the test; a line with no
+.Em \*[Gt]
+at the beginning is considered to be at level 0.
+Tests are arranged in a tree-like hierarchy:
+if the test on a line at level
+.Em n
+succeeds, all following tests at level
+.Em n+1
+are performed, and the messages printed if the tests succeed, until a line
+with level
+.Em n
+(or less) appears.
+For more complex files, one can use empty messages to get just the
+"if/then" effect, in the following way:
+.Bd -literal -offset indent
+0      string   MZ
+\*[Gt]0x18  leshort  \*[Lt]0x40   MS-DOS executable
+\*[Gt]0x18  leshort  \*[Gt]0x3f   extended PC executable (e.g., MS Windows)
+.Ed
+.Pp
+Offsets do not need to be constant, but can also be read from the file
+being examined.
+If the first character following the last
+.Em \*[Gt]
+is a
+.Em \&(
+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:
+.Em (( x [[.,][bBcCeEfFgGhHiIlmsSqQ]][+\-][ y ]) .
+The value of
+.Em x
+is used as an offset in the file.
+A byte, id3 length, short or long is read at that offset depending on the
+.Em [bBcCeEfFgGhHiIlmsSqQ]
+type specifier.
+The value is treated as signed if
+.Dq ,
+is specified or unsigned if
+.Dq .
+is specified.
+The capitalized types interpret the number as a big endian
+value, whereas the small letter versions interpret the number as a little
+endian value;
+the
+.Em m
+type interprets the number as a middle endian (PDP-11) value.
+To that number the value of
+.Em y
+is added and the result is used as an offset in the file.
+The default type if one is not specified is long.
+The following types are recognized:
+.Bl -column -offset indent "Type" "Half/Short" "Little" "Size"
+.It Sy Type	Sy Mnemonic	Sy Endian	Sy Size
+.It bcBc	Byte/Char	N/A	1
+.It efg	Double	Little	8
+.It EFG	Double	Big	8
+.It hs	Half/Short	Little	2
+.It HS	Half/Short	Big	2
+.It i	ID3	Little	4
+.It I	ID3	Big	4
+.It m	Middle	Middle	4
+.It o	Octal	Textual	Variable
+.It q	Quad	Little	8
+.It Q	Quad	Big	8
+.El
+.Pp
+That way variable length structures can be examined:
+.Bd -literal -offset indent
+# MS Windows executables are also valid MS-DOS executables
+0           string  MZ
+\*[Gt]0x18       leshort \*[Lt]0x40   MZ executable (MS-DOS)
+# skip the whole block below if it is not an extended executable
+\*[Gt]0x18       leshort \*[Gt]0x3f
+\*[Gt]\*[Gt](0x3c.l)  string  PE\e0\e0  PE executable (MS-Windows)
+\*[Gt]\*[Gt](0x3c.l)  string  LX\e0\e0  LX executable (OS/2)
+.Ed
+.Pp
+This strategy of examining has a drawback: you must make sure that you
+eventually print something, or users may get empty output (such as when
+there is neither PE\e0\e0 nor LE\e0\e0 in the above example).
+.Pp
+If this indirect offset cannot be used directly, simple calculations are
+possible: appending
+.Em [+-*/%\*[Am]|^]number
+inside parentheses allows one to modify
+the value read from the file before it is used as an offset:
+.Bd -literal -offset indent
+# MS Windows executables are also valid MS-DOS executables
+0           string  MZ
+# sometimes, the value at 0x18 is less that 0x40 but there's still an
+# extended executable, simply appended to the file
+\*[Gt]0x18       leshort \*[Lt]0x40
+\*[Gt]\*[Gt](4.s*512) leshort 0x014c  COFF executable (MS-DOS, DJGPP)
+\*[Gt]\*[Gt](4.s*512) leshort !0x014c MZ executable (MS-DOS)
+.Ed
+.Pp
+Sometimes you do not know the exact offset as this depends on the length or
+position (when indirection was used before) of preceding fields.
+You can specify an offset relative to the end of the last up-level
+field using
+.Sq \*[Am]
+as a prefix to the offset:
+.Bd -literal -offset indent
+0           string  MZ
+\*[Gt]0x18       leshort \*[Gt]0x3f
+\*[Gt]\*[Gt](0x3c.l)  string  PE\e0\e0    PE executable (MS-Windows)
+# immediately following the PE signature is the CPU type
+\*[Gt]\*[Gt]\*[Gt]\*[Am]0       leshort 0x14c     for Intel 80386
+\*[Gt]\*[Gt]\*[Gt]\*[Am]0       leshort 0x184     for DEC Alpha
+.Ed
+.Pp
+Indirect and relative offsets can be combined:
+.Bd -literal -offset indent
+0             string  MZ
+\*[Gt]0x18         leshort \*[Lt]0x40
+\*[Gt]\*[Gt](4.s*512)   leshort !0x014c MZ executable (MS-DOS)
+# if it's not COFF, go back 512 bytes and add the offset taken
+# from byte 2/3, which is yet another way of finding the start
+# of the extended executable
+\*[Gt]\*[Gt]\*[Gt]\*[Am](2.s-514) string  LE      LE executable (MS Windows VxD driver)
+.Ed
+.Pp
+Or the other way around:
+.Bd -literal -offset indent
+0                 string  MZ
+\*[Gt]0x18             leshort \*[Gt]0x3f
+\*[Gt]\*[Gt](0x3c.l)        string  LE\e0\e0  LE executable (MS-Windows)
+# at offset 0x80 (-4, since relative offsets start at the end
+# of the up-level match) inside the LE header, we find the absolute
+# offset to the code area, where we look for a specific signature
+\*[Gt]\*[Gt]\*[Gt](\*[Am]0x7c.l+0x26) string  UPX     \eb, UPX compressed
+.Ed
+.Pp
+Or even both!
+.Bd -literal -offset indent
+0                string  MZ
+\*[Gt]0x18            leshort \*[Gt]0x3f
+\*[Gt]\*[Gt](0x3c.l)       string  LE\e0\e0 LE executable (MS-Windows)
+# at offset 0x58 inside the LE header, we find the relative offset
+# to a data area where we look for a specific signature
+\*[Gt]\*[Gt]\*[Gt]\*[Am](\*[Am]0x54.l-3)  string  UNACE  \eb, ACE self-extracting archive
+.Ed
+.Pp
+If you have to deal with offset/length pairs in your file, even the
+second value in a parenthesized expression can be taken from the file itself,
+using another set of parentheses.
+Note that this additional indirect offset is always relative to the
+start of the main indirect offset.
+.Bd -literal -offset indent
+0                 string       MZ
+\*[Gt]0x18             leshort      \*[Gt]0x3f
+\*[Gt]\*[Gt](0x3c.l)        string       PE\e0\e0 PE executable (MS-Windows)
+# search for the PE section called ".idata"...
+\*[Gt]\*[Gt]\*[Gt]\*[Am]0xf4          search/0x140 .idata
+# ...and go to the end of it, calculated from start+length;
+# these are located 14 and 10 bytes after the section name
+\*[Gt]\*[Gt]\*[Gt]\*[Gt](\*[Am]0xe.l+(-4)) string       PK\e3\e4 \eb, ZIP self-extracting archive
+.Ed
+.Pp
+If you have a list of known values at a particular continuation level,
+and you want to provide a switch-like default case:
+.Bd -literal -offset indent
+# clear that continuation level match
+\*[Gt]18	clear
+\*[Gt]18	lelong	1	one
+\*[Gt]18	lelong	2	two
+\*[Gt]18	default	x
+# print default match
+\*[Gt]\*[Gt]18	lelong	x	unmatched 0x%x
+.Ed
+.Sh SEE ALSO
+.Xr file __CSECTION__
+\- the command that reads this file.
+.Sh BUGS
+The formats
+.Dv long ,
+.Dv belong ,
+.Dv lelong ,
+.Dv melong ,
+.Dv short ,
+.Dv beshort ,
+and
+.Dv leshort
+do not depend on the length of the C data types
+.Dv short
+and
+.Dv long
+on the platform, even though the Single
+.Ux
+Specification implies that they do.  However, as OS X Mountain Lion has
+passed the Single
+.Ux
+Specification validation suite, and supplies a version of
+.Xr file __CSECTION__
+in which they do not depend on the sizes of the C data types and that is
+built for a 64-bit environment in which
+.Dv long
+is 8 bytes rather than 4 bytes, presumably the validation suite does not
+test whether, for example
+.Dv long
+refers to an item with the same size as the C data type
+.Dv long .
+There should probably be
+.Dv type
+names
+.Dv int8 ,
+.Dv uint8 ,
+.Dv int16 ,
+.Dv uint16 ,
+.Dv int32 ,
+.Dv uint32 ,
+.Dv int64 ,
+and
+.Dv uint64 ,
+and specified-byte-order variants of them,
+to make it clearer that those types have specified widths.
+.\"
+.\" 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.