-.\" $File: file.man,v 1.93 2011/03/12 19:01:27 rrt Exp $
+.\" $File: file.man,v 1.94 2011/04/20 19:08:44 christos Exp $
.Dd April 20, 2011
.Dt FILE __CSECTION__
.Os
.Nm
.Bk -words
.Op Fl bchiklLNnprsvz0
-.Op Fl -apple
-.Op Fl -mime-encoding
-.Op Fl -mime-type
+.Op Fl Fl apple
+.Op Fl Fl mime-encoding
+.Op Fl Fl mime-type
.Op Fl e Ar testname
.Op Fl F Ar separator
.Op Fl f Ar namefile
.Op Fl m Ar magicfiles
.Ar
-.Ek -words
+.Ek
.Nm
.Fl C
.Op Fl m Ar magicfiles
.Nm
-.Op Fl -help
+.Op Fl Fl help
.Sh DESCRIPTION
This manual page documents version __VERSION__ of the
.Nm
.Em executable
(the file contains the result of compiling a program
in a form understandable to some
-.Dv UNIX
+.Tn UNIX
kernel or another),
or
.Em data
meaning anything else (data is usually
-.Sq binary
+.Dq binary
or non-printable).
Exceptions are well-known file formats (core files, tar archives)
that are known to contain binary data.
.Em "preserve these keywords" .
Users depend on knowing that all the readable files in a directory
have the word
-.Sq text
+.Dq text
printed.
Don't do as Berkeley did and change
-.Sq shell commands text
+.Dq shell commands text
to
-.Sq shell script .
+.Dq shell script .
.Pp
The filesystem tests are based on examining the return from a
.Xr stat 2
Any known file types appropriate to the system you are running on
(sockets, symbolic links, or named pipes (FIFOs) on those systems that
implement them)
-are intuited if they are defined in
-the system header file
+are intuited if they are defined in the system header file
.In sys/stat.h .
.Pp
The magic tests are used to check for files with data in
.In exec.h
in the standard include directory.
These files have a
-.Sq "magic number"
+.Dq "magic number"
stored in a particular place
near the beginning of the file that tells the
-.Dv UNIX operating system
+.Tn UNIX
+operating system
that the file is a binary executable, and which of several types thereof.
The concept of a
-.Sq "magic"
+.Dq "magic"
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.
If a file passes any of these tests, its character set is reported.
ASCII, ISO-8859-x, UTF-8, and extended-ASCII files are identified
as
-.Sq text
+.Dq text
because they will be mostly readable on nearly any terminal;
UTF-16 and EBCDIC are only
-.Sq character data
+.Dq character data
because, while
they contain text, it is text that will require translation
before it can be read.
it will
attempt to determine in what language the file is written.
The language tests look for particular strings (cf.
-.In names.h
-) that can appear anywhere in the first few blocks of a file.
+.In names.h )
+that can appear anywhere in the first few blocks of a file.
For example, the keyword
.Em .br
indicates that the file is most likely a
.Pp
Any file that cannot be identified as having been written
in any of the character sets listed above is simply said to be
-.Sq data .
+.Dq data .
.Sh OPTIONS
.Bl -tag -width indent
-.It Fl b , -brief
+.It Fl b , Fl Fl brief
Do not prepend filenames to output lines (brief mode).
-.It Fl C , -compile
+.It Fl C , Fl Fl compile
Write a
.Pa magic.mgc
output file that contains a pre-parsed version of the magic file or directory.
-.It Fl c , -checking-printout
+.It Fl c , Fl Fl checking-printout
Cause a checking printout of the parsed form of the magic file.
This is usually used in conjunction with the
.Fl m
flag to debug a new magic file before installing it.
-.It Fl e , -exclude Ar testname
+.It Fl e , Fl Fl exclude Ar testname
Exclude the test named in
.Ar testname
from the list of tests made to determine the file type.
.Dv EMX
application type (only on EMX).
.It ascii
-Various types of text files (this test will try to guess the text encoding, irrespective of the setting of the
+Various types of text files (this test will try to guess the text
+encoding, irrespective of the setting of the
.Sq encoding
option).
.It encoding
.It tar
Examines tar files.
.El
-.It Fl F , -separator Ar separator
+.It Fl F , Fl Fl separator Ar separator
Use the specified string as the separator between the filename and the
file result returned.
Defaults to
.Sq \&: .
-.It Fl f , -files-from Ar namefile
+.It Fl f , Fl Fl files-from Ar namefile
Read the names of the files to be examined from
.Ar namefile
(one per line)
to test the standard input, use
.Sq -
as a filename argument.
-.It Fl h , -no-dereference
+.It Fl h , Fl Fl no-dereference
option causes symlinks not to be followed
(on systems that support symbolic links).
This is the default if the environment variable
.Dv POSIXLY_CORRECT
is not defined.
-.It Fl i , -mime
+.It Fl i , Fl Fl mime
Causes the file command to output mime type strings rather than the more
traditional human readable ones.
Thus it may say
.Sq text/plain; charset=us-ascii
rather than
-.Sq ASCII text .
-In order for this option to work, file changes the way
+.Dq ASCII text .
+In order for this option to work,
+.Nm
+changes the way
it handles files recognized by the command itself (such as many of the
text file types, directories etc), and makes use of an alternative
-.Sq magic
+.Dq magic
file.
-(See the FILES section, below).
-.It Fl -mime-type , -mime-encoding
+(See the
+.Sx FILES
+section, below).
+.It Fl Fl mime-type , Fl Fl mime-encoding
Like
.Fl i ,
but print only the specified element(s).
-.It Fl k , -keep-going
+.It Fl k , Fl Fl keep-going
Don't stop at the first match, keep going.
Subsequent matches will be
have the string
.Sq "\[rs]012\- "
prepended.
(If you want a newline, see the
-.Sq "\-r"
+.Fl r
option.)
-.It Fl l , -list
+.It Fl l , Fl Fl list
Print information about the strength of each magic pattern.
-.It Fl L , -dereference
+.It Fl L , Fl Fl dereference
option causes symlinks to be followed, as the like-named option in
.Xr ls 1
(on systems that support symbolic links).
This is the default if the environment variable
-.Dv POSIXLY_CORRECT
+.Ev POSIXLY_CORRECT
is defined.
.It Fl l
Shows sorted patterns list in the order which is used for the matching.
-.It Fl m , -magic-file Ar magicfiles
+.It Fl m , Fl Fl magic-file Ar magicfiles
Specify an alternate list of files and directories containing magic.
This can be a single item, or a colon-separated list.
-If a compiled magic file is found alongside a file or directory, it will be used instead.
-.It Fl N , -no-pad
+If a compiled magic file is found alongside a file or directory,
+it will be used instead.
+.It Fl N , Fl Fl no-pad
Don't pad filenames so that they align in the output.
-.It Fl n , -no-buffer
+.It Fl n , Fl Fl no-buffer
Force stdout to be flushed after checking each file.
This is only useful if checking a list of files.
It is intended to be used by programs that want filetype output from a pipe.
-.It Fl p , -preserve-date
+.It Fl p , Fl Fl preserve-date
On systems that support
-.Xr utime 2
+.Xr utime 3
or
.Xr utimes 2 ,
attempt to preserve the access time of files analyzed, to pretend that
.Nm
never read them.
-.It Fl r , -raw
+.It Fl r , Fl Fl raw
Don't translate unprintable characters to \eooo.
Normally
.Nm
translates unprintable characters to their octal representation.
-.It Fl s , -special-files
+.It Fl s , Fl Fl special-files
Normally,
.Nm
only attempts to read and determine the type of argument files which
to disregard the file size as reported by
.Xr stat 2
since on some systems it reports a zero size for raw disk partitions.
-.It Fl v , -version
+.It Fl v , Fl Fl version
Print the version of the program and exit.
-.It Fl z , -uncompress
+.It Fl z , Fl Fl uncompress
Try to look inside compressed files.
-.It Fl 0 , -print0
+.It Fl 0 , Fl Fl print0
Output a null character
.Sq \e0
after the end of the filename.
.El
.Sh ENVIRONMENT
The environment variable
-.Dv MAGIC
+.Ev MAGIC
can be used to set the default magic file name.
If that variable is set, then
.Nm
.Pa $HOME/.magic .
.Nm
adds
-.Sq .mgc
+.Dq Pa .mgc
to the value of this variable as appropriate.
However,
.Pa file
.Pa file.mime
to be considered.
The environment variable
-.Dv POSIXLY_CORRECT
+.Ev POSIXLY_CORRECT
controls (on systems that support symbolic links), whether
.Nm
will attempt to follow symlinks or not.
options.
.Sh SEE ALSO
.Xr magic __FSECTION__ ,
-.Xr strings 1 ,
-.Xr od 1 ,
.Xr hexdump 1 ,
-.Xr file 1posix
+.Xr od 1 ,
+.Xr strings 1 ,
.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
as a delimiter, so that spaces in pattern strings must be escaped.
For example,
.Bd -literal -offset indent
->10 string language impress\ (imPRESS data)
+\*[Gt]10 string language impress\ (imPRESS data)
.Ed
.Pp
in an existing magic file would have to be changed to
.Bd -literal -offset indent
->10 string language\e impress (imPRESS data)
+\*[Gt]10 string language\e impress (imPRESS data)
.Ed
.Pp
In addition, in this version, if a pattern string contains a backslash,
SunOS releases 3.2 and later from Sun Microsystems include a
.Nm
command derived from the System V one, but with some extensions.
-My version differs from Sun's only in minor ways.
+This version differs from Sun's only in minor ways.
It includes the extension of the
-.Sq &
+.Sq \*[Am]
operator, used as,
for example,
.Bd -literal -offset indent
->16 long&0x7fffffff >0 not stripped
+\*[Gt]16 long\*[Am]0x7fffffff \*[Gt]0 not stripped
.Ed
.Sh MAGIC DIRECTORY
The magic file entries have been collected from various sources,
command uses a magic file,
keep the old magic file around for comparison purposes
(rename it to
-.Pa __MAGIC__.orig ).
+.Pa __MAGIC__.orig ) .
.Sh EXAMPLES
.Bd -literal -offset indent
$ file file.c file /dev/{wd0a,hda}
the first version.
Geoff Collyer found several inadequacies
and provided some magic file entries.
-Contributions by the `&' operator by Rob McMahon
+Contributions by the
+.Sq \*[Am]
+operator by Rob McMahon,
.Aq cudcv@warwick.ac.uk ,
1989.
.Pp
-Guy Harris
-.Aq guy@netapp.com
+Guy Harris,
+.Aq guy@netapp.com ,
made many changes from 1993 to the present.
+1989.
.Pp
Primary development and maintenance from 1990 to the present by
Christos Zoulas
magic file and internal logic.
.Pp
Altered by Eric Fischer
-.Aq enf@pobox.com
-July, 2000, to identify character codes and attempt to identify the languages
+.Aq enf@pobox.com ,
+July, 2000,
+to identify character codes and attempt to identify the languages
of non-ASCII files.
.Pp
Altered by Reuben Thomas
COPYING in the source distribution.
.Pp
The files
-.Dv tar.h
+.Pa tar.h
and
-.Dv is_tar.c
+.Pa is_tar.c
were written by John Gilmore from his public-domain
.Xr tar 1
program, and are not covered by the above license.
Add an option to print URLs for the sources of the file descriptions.
.Sh AVAILABILITY
You can obtain the original author's latest version by anonymous FTP
-from
-.Dv ftp.astron.com
+on
+.Pa ftp.astron.com
in the directory
-.Dv /pub/file/file-X.YZ.tar.gz
+.Pa /pub/file/file-X.YZ.tar.gz .
-.\" $File: libmagic.man,v 1.22 2010/06/01 12:31:31 christos Exp $
+.\" $File: libmagic.man,v 1.23 2011/01/14 21:59:17 rrt Exp $
.\"
.\" Copyright (c) Christos Zoulas 2003.
.\" All Rights Reserved.
.Nm magic_check ,
.Nm magic_compile ,
.Nm magic_load
-.Nd Magic number recognition library.
+.Nd Magic number recognition library
.Sh LIBRARY
.Lb libmagic
.Sh SYNOPSIS
.Ft const char *
.Fn magic_file "magic_t cookie, const char *filename"
.Ft const char *
-.Fn magic_buffer "magic_t cookie, const void *buffer, size_t length"
+.Fn magic_buffer "magic_t cookie" "const void *buffer" "size_t length"
.Ft int
-.Fn magic_setflags "magic_t cookie, int flags"
+.Fn magic_setflags "magic_t cookie" "int flags"
.Ft int
-.Fn magic_check "magic_t cookie, const char *filename"
+.Fn magic_check "magic_t cookie" "const char *filename"
.Ft int
-.Fn magic_compile "magic_t cookie, const char *filename"
+.Fn magic_compile "magic_t cookie" "const char *filename"
.Ft int
-.Fn magic_load "magic_t cookie, const char *filename"
+.Fn magic_load "magic_t cookie" "const char *filename"
.Sh DESCRIPTION
These functions
operate on the magic database file
.Pp
The function
.Fn magic_open
-creates a magic cookie pointer and returns it. It returns NULL if
-there was an error allocating the magic cookie. The
+creates a magic cookie pointer and returns it.
+It returns
+.Dv NULL
+if there was an error allocating the magic cookie.
+The
.Ar flags
argument specifies how the other magic functions should behave:
.Bl -tag -width MAGIC_COMPRESS
Check the magic database for consistency and print warnings to stderr.
.It Dv MAGIC_PRESERVE_ATIME
On systems that support
-.Xr utime 2
+.Xr utime 3
or
.Xr utimes 2 ,
attempt to preserve the access time of files analysed.
.Pp
The
.Fn magic_error
-function returns a textual explanation of the last error, or NULL if there was
-no error.
+function returns a textual explanation of the last error, or
+.Dv NULL
+if there was no error.
.Pp
The
.Fn magic_errno
.Fn magic_file
function returns a textual description of the contents of the
.Ar filename
-argument, or NULL if an error occurred.
+argument, or
+.Dv NULL
+if an error occurred.
If the
.Ar filename
-is NULL, then stdin is used.
+is
+.Dv NULL ,
+then stdin is used.
.Pp
The
.Fn magic_descriptor
function returns a textual description of the contents of the
.Ar fd
-argument, or NULL if an error occurred.
+argument, or
+.Dv NULL
+if an error occurred.
.Pp
The
.Fn magic_buffer
.Fn magic_setflags
function sets the
.Ar flags
-described above. Note that using both MIME flags together can also
+described above.
+Note that using both MIME flags together can also
return extra information on the charset.
.Pp
The
function can be used to check the validity of entries in the colon
separated database files passed in as
.Ar filename ,
-or NULL for the default database. It returns 0 on success and -1 on
-failure.
+or
+.Dv NULL
+for the default database.
+It returns 0 on success and \-1 on failure.
.Pp
The
.Fn magic_compile
function can be used to compile the the colon
separated list of database files passed in as
.Ar filename ,
-or NULL for the default database. It returns 0 on success and -1 on
-failure. The compiled files created are named from the
+or
+.Dv NULL
+for the default database.
+It returns 0 on success and \-1 on failure.
+The compiled files created are named from the
.Xr basename 1
of each file argument with
.Dq .mgc
function must be used to load the the colon
separated list of database files passed in as
.Ar filename ,
-or NULL for the default database file
-before any magic queries can performed.
+or
+.Dv NULL
+for the default database file before any magic queries can performed.
.Pp
-The default database file is named by the MAGIC environment variable. If
-that variable is not set, the default database file name is __MAGIC__.
+The default database file is named by the MAGIC environment variable.
+If that variable is not set, the default database file name is __MAGIC__.
.Fn magic_load
adds
.Dq .mgc
.Sh RETURN VALUES
The function
.Fn magic_open
-returns a magic cookie on success and NULL on failure setting errno to
-an appropriate value. It will set errno to EINVAL if an unsupported
-value for flags was given.
+returns a magic cookie on success and
+.Dv NULL
+on failure setting errno to an appropriate value.
+It will set errno to
+.Er EINVAL
+if an unsupported value for flags was given.
The
.Fn magic_load ,
.Fn magic_compile ,
and
.Fn magic_check
-functions return 0 on success and -1 on failure.
+functions return 0 on success and \-1 on failure.
The
.Fn magic_file ,
and
.Fn magic_buffer
-functions return a string on success and NULL on failure. The
+functions return a string on success and
+.Dv NULL
+on failure.
+The
.Fn magic_error
function returns a textual description of the errors of the above
-functions, or NULL if there was no error.
+functions, or
+.Dv NULL
+if there was no error.
Finally,
.Fn magic_setflags
-returns -1 on systems that don't support
-.Xr utime 2 ,
+returns \-1 on systems that don't support
+.Xr utime 3 ,
or
.Xr utimes 2
when
.Xr file __CSECTION__ ,
.Xr magic __FSECTION__
.Sh AUTHORS
-Måns Rullgård Initial libmagic implementation,
-and configuration.
-.br
-Christos Zoulas API cleanup, error code and allocation handling.
+.An M\(oans Rullg\(oard
+Initial libmagic implementation, and configuration.
+.An Christos Zoulas
+API cleanup, error code and allocation handling.
-.\" $File: magic.man,v 1.67 2011/04/15 22:08:52 christos Exp $
+.\" $File: magic.man,v 1.68 2011/04/20 19:08:44 christos Exp $
.Dd April 20, 2011
.Dt MAGIC __FSECTION__
.Os
Starting at the given offset, consult the magic database again.
.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 type specification can be optionally
-followed by
+(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 type specification can be optionally followed by
.Dv /[c][s] .
The
.Dq c
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 modifier flags
-(if any) must be followed by
+A literal string search starting at the given offset.
+The same modifier flags can be used as for string patterns.
+The modifier flags (if any) must be followed by
.Dv /number
the range, that is, the number of positions at which the match will be
-attempted, starting from the start offset. This is suitable for
+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 offset works as for regex.
+escapes for special characters.
+The offset works as for regex.
.It Dv default
This is intended to be used with the test
.Em x
.El
.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
+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
+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
+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.
projects / file / commitdiff