1** README for file(1) Command ** 2@(#) $File: README,v 1.45 2013/01/11 16:51:01 christos Exp $ 3 4Mailing List: file@mx.gw.com 5Bug tracker: http://bugs.gw.com/ 6E-mail: christos@astron.com 7 8Phone: Do not even think of telephoning me about this program. Send cash first! 9 10This is Release 5.x of Ian Darwin's (copyright but distributable) 11file(1) command, an implementation of the Unix File(1) command. 12It knows the 'magic number' of several thousands of file types. 13This version is the standard "file" command for Linux, 14*BSD, and other systems. (See "patchlevel.h" for the exact release number). 15 16You can download the latest version of file from: 17 18 ftp://ftp.astron.com/pub/file/ 19 20A public read-only git repository is available at: 21 22 https://github.com/glensc/file 23 24The major changes for 5.x are CDF file parsing, indirect magic, and 25overhaul in mime and ascii encoding handling. 26 27The major feature of 4.x is the refactoring of the code into a library, 28and the re-write of the file command in terms of that library. The library 29itself, libmagic can be used by 3rd party programs that wish to identify 30file types without having to fork() and exec() file. The prime contributor 31for 4.0 was M\xe5ns Rullg\xe5rd. 32 33UNIX is a trademark of UNIX System Laboratories. 34 35The prime contributor to Release 3.8 was Guy Harris, who put in megachanges 36including byte-order independence. 37 38The prime contributor to Release 3.0 was Christos Zoulas, who put 39in hundreds of lines of source code changes, including his own 40ANSIfication of the code (I liked my own ANSIfication better, but 41his (__P()) is the "Berkeley standard" way of doing it, and I wanted UCB 42to include the code...), his HP-like "indirection" (a feature of 43the HP file command, I think), and his mods that finally got the 44uncompress (-z) mode finished and working. 45 46This release has compiled in numerous environments; see PORTING 47for a list and problems. 48 49This fine freeware file(1) follows the USG (System V) model of the file 50command, rather than the Research (V7) version or the V7-derived 4.[23] 51Berkeley one. That is, the file /etc/magic contains much of the ritual 52information that is the source of this program's power. My version 53knows a little more magic (including tar archives) than System V; the 54/etc/magic parsing seems to be compatible with the (poorly documented) 55System V /etc/magic format (with one exception; see the man page). 56 57In addition, the /etc/magic file is built from a subdirectory 58for easier(?) maintenance. I will act as a clearinghouse for 59magic numbers assigned to all sorts of data files that 60are in reasonable circulation. Send your magic numbers, 61in magic(5) format please, to the maintainer, Christos Zoulas. 62 63COPYING - read this first. 64README - read this second (you are currently reading this file). 65INSTALL - read on how to install 66 67src/apprentice.c - parses /etc/magic to learn magic 68src/apptype.c - used for OS/2 specific application type magic 69src/asprintf.c - replacement for OS's that don't have it. 70src/ascmagic.c - third & last set of tests, based on hardwired assumptions. 71src/asctime_r.c - for systems that don't have it. 72src/asprintf.c - for systems that don't have it. 73src/cdf.c - parser for Microsoft Compound Document Files 74src/cdf_time.c - time converter for CDF. 75src/compress.c - handles decompressing files to look inside. 76src/ctime_r.c - for systems that don't have it. 77src/encoding.c - handles unicode encodings 78src/file.c - the main program 79src/file.h - header file 80src/fsmagic.c - first set of tests the program runs, based on filesystem info 81src/funcs.c - utilility functions 82src/getopt_long.c - for systems that don't have it. 83src/getline.c - for systems that don't have it. 84src/is_tar.c, tar.h - knows about tarchives (courtesy John Gilmore). 85src/names.h - header file for ascmagic.c 86src/magic.c - the libmagic api 87src/print.c - print results, errors, warnings. 88src/readcdf.c - CDF wrapper. 89src/readelf.[ch] - Stand-alone elf parsing code. 90src/softmagic.c - 2nd set of tests, based on /etc/magic 91src/strlcat.c - for systems that don't have it. 92src/strlcpy.c - for systems that don't have it. 93src/vasprintf.c - for systems that don't have it. 94doc/file.man - man page for the command 95doc/magic.man - man page for the magic file, courtesy Guy Harris. 96 Install as magic.4 on USG and magic.5 on V7 or Berkeley; cf Makefile. 97Magdir - directory of /etc/magic pieces 98------------------------------------------------------------------------------ 99 100If you submit a new magic entry please make sure you read the following 101guidelines: 102 103- Initial match is preferably at least 32 bits long, and is a _unique_ match 104- If this is not feasible, use additional check 105- Match of <= 16 bits are not accepted 106- Delay printing string as much as possible, don't print output too early 107- Avoid printf arbitrary byte as string, which can be a source of 108 crash and buffer overflow 109 110- Provide complete information with entry: 111 * One line short summary 112 * Optional long description 113 * File extension, if applicable 114 * Full name and contact method (for discussion when entry has problem) 115 * Further reference, such as documentation of format 116 117------------------------------------------------------------------------------ 118 119Parts of this software were developed at SoftQuad Inc., developers 120of SGML/HTML/XML publishing software, in Toronto, Canada. 121SoftQuad was swallowed up by Corel in 2002 and does not exist any longer. 122