mdoc'ify; from FreeBSD, with many modifications by me.

1 files changed, 299 insertions, 194 deletions

diff --git a/usr.bin/file/file.1 b/usr.bin/file/file.1
index af7b5a4c98e..4f23ce148c5 100644
--- a/usr.bin/file/file.1
+++ b/usr.bin/file/file.1
@@ -1,58 +1,61 @@
-.\" $OpenBSD: file.1,v 1.7 2000/03/04 22:19:23 aaron Exp $
-.TH FILE 1 "Copyrighted but distributable"
-.SH NAME
-file
-\- determine file type
-.SH SYNOPSIS
-.B file
-[
-.B \-vczL
-]
-[
-.B \-f
-namefile ]
-[
-.B \-m
-magicfiles ]
-file ...
-.SH DESCRIPTION
+.\" $OpenBSD: file.1,v 1.8 2000/03/06 02:38:19 aaron Exp $
+.\" $FreeBSD: src/usr.bin/file/file.1,v 1.16 2000/03/01 12:19:39 sheldonh Exp $
+.Dd July 30, 1997
+.Dt FILE 1
+.Os
+.Sh NAME
+.Nm file
+.Nd determine file type
+.Sh SYNOPSIS
+.Nm file
+.Op Fl vczL
+.Op Fl f Ar namefile
+.Op Fl m Ar magicfiles
+.Ar file Op Ar ...
+.Sh DESCRIPTION
 This manual page documents version 3.22 of the
-.B file
+.Nm
 command.
-.B File
+.Nm
 tests each argument in an attempt to classify it.
 There are three sets of tests, performed in this order:
 filesystem tests, magic number tests, and language tests.
-The
-.I first
-test that succeeds causes the file type to be printed.
-.PP
+The first test that succeeds causes the file type to be printed.
+.Pp
 The type printed will usually contain one of the words
-.B text
+.Dq text
 (the file contains only
-.SM ASCII
+.Tn ASCII
 characters and is probably safe to read on an
-.SM ASCII
+.Tn ASCII
 terminal),
-.B executable
+.Dq executable
 (the file contains the result of compiling a program
-in a form understandable to some \s-1UNIX\s0 kernel or another),
+in a form understandable to some
+.Ux
+kernel or another),
 or
-.B data
-meaning anything else (data is usually `binary' or non-printable).
+.Dq data
+meaning anything else (data is usually binary or non-printable).
+.Pp
 Exceptions are well-known file formats (core files, tar archives)
 that are known to contain binary data.
 When modifying the file
-.I /etc/magic
+.Pa /etc/magic
 or the program itself,
-.B "preserve these keywords" .
+.Em "preserve these keywords" .
+.Pp
 People depend on knowing that all the readable files in a directory
-have the word ``text'' printed.
-Don't do as Berkeley did \- change ``shell commands text''
-to ``shell script''.
-.PP
+have the word
+.Dq text
+printed.
+Don't do as Berkeley did; change
+.Dq shell commands text
+to
+.Dq shell script .
+.Pp
 The filesystem tests are based on examining the return from a
-.BR stat (2)
+.Xr stat 2
 system call.
 The program checks to see if the file is empty,
 or if it's some sort of special file.
@@ -61,277 +64,379 @@ Any known file types appropriate to the system you are running on
 implement them)
 are intuited if they are defined in
 the system header file
-.IR sys/stat.h  .
-.PP
+.Aq Pa sys/stat.h  .
+.Pp
 The magic number tests are used to check for files with data in
 particular fixed formats.
 The canonical example of this is a binary executable (compiled program)
-.I a.out
+.Pa a.out
 file, whose format is defined in
-.I a.out.h
+.Aq Pa a.out.h
 and possibly
-.I exec.h
+.Aq Pa exec.h
 in the standard include directory.
-These files have a `magic number' stored in a particular place
-near the beginning of the file that tells the \s-1UNIX\s0 operating system
+These files have a
+.Dq magic number
+stored in a particular place
+near the beginning of the file that tells the
+.Ux
+operating system
 that the file is a binary executable, and which of several types thereof.
-The concept of `magic number' has been applied by extension to data files.
+.Pp
+The concept of magic number has been applied by extension to data files.
 Any file with some invariant identifier at a small fixed
 offset into the file can usually be described in this way.
 The information in these files is read from the magic file
-.I /etc/magic.
-.PP
+.Pa /etc/magic .
+.Pp
 If an argument appears to be an
-.SM ASCII
+.Tn ASCII
 file,
-.B file
+.Nm
 attempts to guess its language.
 The language tests look for particular strings (cf
-.IR names.h )
+.Pa names.h )
 that can appear anywhere in the first few blocks of a file.
 For example, the keyword
-.B .br
+.Em .br
 indicates that the file is most likely a
-.BR troff (1)
+.Xr troff 1
 input file, just as the keyword
-.B struct
+.Li struct
 indicates a C program.
 These tests are less reliable than the previous
 two groups, so they are performed last.
 The language test routines also test for some miscellany
 (such as
-.BR tar (1)
+.Xr tar 1
 archives) and determine whether an unknown file should be
-labelled as `ascii text' or `data'.
-.SH OPTIONS
-.TP 8
-.B \-v
+labelled as
+.Dq ASCII text
+or
+.Dq data .
+.Pp
+The options are as follows:
+.Bl -tag -width indent
+.It Fl v
 Print the version of the program and exit.
-.TP 8
-.B \-m list
-Specify an alternate list of files containing magic numbers.
+.It Fl m Ar list
+Specify an alternate
+.Ar list
+of files containing magic numbers.
 This can be a single file, or a colon-separated list of files.
-.TP 8
-.B \-z
+.It Fl z
 Try to look inside compressed files.
-.TP 8
-.B \-c
+.It Fl c
 Cause a checking printout of the parsed form of the magic file.
 This is usually used in conjunction with
-.B \-m
+.Fl m
 to debug a new magic file before installing it.
-.TP 8
-.B \-f namefile
+.It Fl f Ar namefile
 Read the names of the files to be examined from
-.I namefile
+.Ar namefile
 (one per line)
 before the argument list.
 Either
-.I namefile
+.Ar namefile
 or at least one filename argument must be present;
-to test the standard input, use ``-'' as a filename argument.
-.TP 8
-.B \-L
-option causes symlinks to be followed, as the like-named option in
-.BR ls (1).
+to test the standard input, use
+.Dq -
+as a filename argument.
+.It Fl L
+Cause symlinks to be followed, as the like-named option in
+.Xr ls 1 .
 (on systems that support symbolic links).
-.SH FILES
-.I /etc/magic
-\- default list of magic numbers
-.SH ENVIRONMENT
-The environment variable
-.B MAGIC
-can be used to set the default magic number files.
-.SH SEE ALSO
-.BR magic (5)
-\- description of magic file format.
-.br
-.BR strings (1), " od" (1)
-\- tools for examining non-textfiles.
-.SH STANDARDS CONFORMANCE
+.El
+.Sh FILES
+.Bl -tag -width /etc/magic -compact
+.It Pa /etc/magic
+default list of magic numbers
+.El
+.Sh ENVIRONMENT
+The following environment varibles affect the execution of
+.Nm file :
+.Pp
+.Bl -tag -width indent
+.Ev MAGIC
+Default magic number files.
+.El
+.Sh SEE ALSO
+.Xr hexdump 1 ,
+.Xr od 1 ,
+.Xr strings 1 ,
+.Xr magic 5
+.Sh STANDARDS CONFORMANCE
 This program is believed to exceed the System V Interface Definition
 of FILE(CMD), as near as one can determine from the vague language
 contained therein.
 Its behaviour is mostly compatible with the System V program of the same name.
 This version knows more magic, however, so it will produce
 different (albeit more accurate) output in many cases.
-.PP
+.Pp
 The one significant difference
 between this version and System V
-is that this version treats any whitespace
+is that this version treats any white space
 as a delimiter, so that spaces in pattern strings must be escaped.
 For example,
-.br
->10	string	language impress\ 	(imPRESS data)
-.br
+.Pp
+>10     string  language impress\       (imPRESS data)
+.Pp
 in an existing magic file would have to be changed to
-.br
->10	string	language\e impress	(imPRESS data)
-.br
+.Pp
+>10     string  language\e impress      (imPRESS data)
+.Pp
 In addition, in this version, if a pattern string contains a backslash,
 it must be escaped.  For example
-.br
-0	string		\ebegindata	Andrew Toolkit document
-.br
+.Pp
+0       string          \ebegindata     Andrew Toolkit document
+.Pp
 in an existing magic file would have to be changed to
-.br
-0	string		\e\ebegindata	Andrew Toolkit document
-.br
-.PP
+.Pp
+0       string          \e\ebegindata   Andrew Toolkit document
+.Pp
 SunOS releases 3.2 and later from Sun Microsystems include a
-.BR file (1)
+.Xr file 1
 command derived from the System V one, but with some extensions.
 My version differs from Sun's only in minor ways.
-It includes the extension of the `&' operator, used as,
+It includes the extension of the
+.Ql &
+operator, used as,
 for example,
-.br
->16	long&0x7fffffff	>0		not stripped
-.SH MAGIC DIRECTORY
+.Pp
+>16     long&0x7fffffff >0              not stripped
+.Sh MAGIC DIRECTORY
 The magic file entries have been collected from various sources,
 mainly USENET, and contributed by various authors.
-Christos Zoulas (address below) will collect additional
+.An Christos Zoulas
+(address below) will collect additional
 or corrected magic file entries.
 A consolidation of magic file entries
 will be distributed periodically.
-.PP
 The order of entries in the magic file is significant.
 Depending on what system you are using, the order that
 they are put together may be incorrect.
 If your old
-.B file
+.Nm
 command uses a magic file,
 keep the old magic file around for comparison purposes
 (rename it to
-.IR /etc/magic.orig ).
-.SH HISTORY
+.Pa /etc/magic.orig ) .
+.Sh HISTORY
 There has been a
-.B file
-command in every \s-1UNIX\s0 since at least Research Version 6
+.Nm
+command in every
+.Ux
+since at least Research Version 6
 (man page dated January, 1975).
 The System V version introduced one significant major change:
 the external list of magic number types.
 This slowed the program down slightly but made it a lot more flexible.
-.PP
+.Pp
 This program, based on the System V version,
-was written by Ian Darwin without looking at anybody else's source code.
-.PP
-John Gilmore revised the code extensively, making it better than
+was written by
+.An Ian Darwin
+without looking at anybody else's source code.
+.Pp
+.An John Gilmore
+revised the code extensively, making it better than
 the first version.
-Geoff Collyer found several inadequacies
+.An Geoff Collyer
+found several inadequacies
 and provided some magic file entries.
 The program has undergone continued evolution since.
-.SH AUTHOR
-Written by Ian F. Darwin, ian@darwinsys.com.
-.PP
-Altered by Rob McMahon, cudcv@warwick.ac.uk, 1989, to extend the `&' operator
-from simple `x&y != 0' to `x&y op z'.
-.PP
-Altered by Guy Harris, guy@auspex.com, 1993, to:
-.RS
-.PP
-put the ``old-style'' `&'
-operator back the way it was, because 1) Rob McMahon's change broke the
-previous style of usage, 2) the SunOS ``new-style'' `&' operator,
-which this version of
-.B file
-supports, also handles `x&y op z', and 3) Rob's change wasn't documented
-in any case;
-.PP
-put in multiple levels of `>';
-.PP
-put in ``beshort'', ``leshort'', etc. keywords to look at numbers in the
+.Sh AUTHORS
+Written by
+.An Ian F. Darwin Aq ian@sq.com ,
+UUCP address {utzoo | ihnp4}!darwin!ian,
+postal address: P.O. Box 603, Station F, Toronto, Ontario, CANADA M4Y 2L8.
+.Pp
+Altered by
+.An Rob McMahon Aq cudcv@warwick.ac.uk ,
+1989, to extend the
+.Ql &
+operator from simple
+.Dq x&y != 0
+to
+.Dq x&y op z .
+.Pp
+Altered by
+.An Guy Harris Aq guy@auspex.com ,
+1993, to:
+.Bl -item -offset indent
+.It
+put the
+.Dq old-style
+.Ql &
+operator back the way it was, because
+.Bl -enum -offset indent
+.It
+Rob McMahon's change broke the
+previous style of usage,
+.It
+The SunOS
+.Dq new-style
+.Ql &
+operator, which this version of
+.Nm
+supports, also handles
+.Dq x&y op z ,
+.It
+Rob's change wasn't documented in any case;
+.El
+.It
+put in multiple levels of
+.Ql > ;
+.It
+put in
+.Dq beshort ,
+.Dq leshort ,
+etc. keywords to look at numbers in the
 file in a specific byte order, rather than in the native byte order of
 the process running
-.BR file .
-.RE
-.PP
-Changes by Ian Darwin and various authors including
-Christos Zoulas (christos@deshaw.com), 1990-1997.
-.SH LEGAL NOTICE
-This program is distributed under the terms of the accompanying
-license file LEGAL.NOTICE.
-.PP
-A few support files (\fIgetopt\fP, \fIstrtok\fP)
+.Nm file .
+.El
+.Pp
+Changes by
+.An Ian Darwin
+and various authors including
+.An Christos Zoulas Aq christos@deshaw.com ,
+1990-1992.
+.Sh LEGAL NOTICE
+Copyright (c) Ian F. Darwin, Toronto, Canada,
+1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993.
+.Pp
+This software is not subject to and may not be made subject to any
+license of the American Telephone and Telegraph Company, Sun
+Microsystems Inc., Digital Equipment Inc., Lotus Development Inc., the
+Regents of the University of California, The X Consortium or MIT, or
+The Free Software Foundation.
+.Pp
+This software is not subject to any export provision of the United States
+Department of Commerce, and may be exported to any country or planet.
+.Pp
+Permission is granted to anyone to use this software for any purpose on
+any computer system, and to alter it and redistribute it freely, subject
+to the following restrictions:
+.Bl -enum -offset indent
+.It
+The author is not responsible for the consequences of use of this
+software, no matter how awful, even if they arise from flaws in it;
+.It
+The origin of this software must not be misrepresented, either by
+explicit claim or by omission.  Since few users ever read sources,
+credits must appear in the documentation;
+.It
+Altered versions must be plainly marked as such, and must not be
+misrepresented as being the original software.  Since few users
+ever read sources, credits must appear in the documentation;
+.It
+This notice may not be removed or altered.
+.El
+.Pp
+A few support files
+.Pf ( Fn getopt ,
+.Fn strtok )
 distributed with this package
-are by Henry Spencer and are subject to the same terms as above.
-.PP
-A few simple support files (\fIstrtol\fP, \fIstrchr\fP)
+are by
+.An Henry Spencer
+and are subject to the same terms as above.
+.Pp
+A few simple support files
+.Pf ( Fn strtol ,
+.Fn strchr )
 distributed with this package
 are in the public domain; they are so marked.
-.PP
+.Pp
 The files
-.I tar.h
+.Pa tar.h
 and
-.I is_tar.c
-were written by John Gilmore from his public-domain
-.B tar
+.Pa is_tar.c
+were written by
+.An John Gilmore
+from his public-domain
+.Nm tar
 program, and are not covered by the above restrictions.
-.SH BUGS
+.Sh BUGS
 There must be a better way to automate the construction of the Magic
-file from all the glop in Magdir. What is it?
+file from all the glop in Magdir.
+What is it?
 Better yet, the magic file should be compiled into binary (say,
-.BR ndbm (3)
+.Xr ndbm 3
 or, better yet, fixed-length
-.SM ASCII
+.Tn ASCII
 strings for use in heterogenous network environments) for faster startup.
 Then the program would run as fast as the Version 7 program of the same name,
 with the flexibility of the System V version.
-.PP
-.B File
+.Pp
+.Nm
 uses several algorithms that favor speed over accuracy,
 thus it can be misled about the contents of
-.SM ASCII
+.Tn ASCII
 files.
-.PP
+.Pp
 The support for
-.SM ASCII
+.Tn ASCII
 files (primarily for programming languages)
 is simplistic, inefficient and requires recompilation to update.
-.PP
-There should be an ``else'' clause to follow a series of continuation lines.
-.PP
+.Pp
+There should be an
+.Dq else
+clause to follow a series of continuation lines.
+.Pp
 The magic file and keywords should have regular expression support.
 Their use of
-.SM "ASCII TAB"
+.Tn ASCII TAB
 as a field delimiter is ugly and makes
 it hard to edit the files, but is entrenched.
-.PP
+.Pp
 It might be advisable to allow upper-case letters in keywords
 for e.g.,
-.BR troff (1)
+.Xr troff 1
 commands vs man page macros.
 Regular expression support would make this easy.
-.PP
+.Pp
 The program doesn't grok \s-2FORTRAN\s0.
 It should be able to figure \s-2FORTRAN\s0 by seeing some keywords which
 appear indented at the start of line.
 Regular expression support would make this easy.
-.PP
+.Pp
 The list of keywords in
-.I ascmagic
+.Em ascmagic
 probably belongs in the Magic file.
-This could be done by using some keyword like `*' for the offset value.
-.PP
-Another optimisation would be to sort
+This could be done by using some keyword like
+.Ql *
+for the offset value.
+.Pp
+Another optimization would be to sort
 the magic file so that we can just run down all the
 tests for the first byte, first word, first long, etc, once we
 have fetched it.  Complain about conflicts in the magic file entries.
 Make a rule that the magic entries sort based on file offset rather
 than position within the magic file?
-.PP
+.Pp
 The program should provide a way to give an estimate
-of ``how good'' a guess is.
-We end up removing guesses (e.g. ``From '' as first 5 chars of file) because
-they are not as good as other guesses (e.g. ``Newsgroups:'' versus
-"Return-Path:").  Still, if the others don't pan out, it should be
+of
+.Dq how good
+a guess is.
+We end up removing guesses (e.g.,
+.Dq From\ 
+as first 5 chars of file) because
+they are not as good as other guesses (e.g.,
+.Dq Newsgroups:
+versus
+.Qq Return-Path: ) .
+Still, if the others don't pan out, it should be
 possible to use the first guess.
-.PP
-This program is slower than some vendors' file commands.
-.PP
+.Pp
+This program is slower than some vendors'
+.Nm
+commands.
+.Pp
 This manual page, and particularly this section, is too long.
-.SH AVAILABILITY
+.Sh AVAILABILITY
 You can obtain the original author's latest version by anonymous FTP
-at
-.I ftp://ftp.astron.com/pub/file/
-with a name like
-.I file-X.YY.tar.gz .
+on
+.Em ftp.deshaw.com
+in the directory
+.Pa /pub/file/file-X.YY.tar.gz
+