1 GNU gzip NEWS -*- outline -*-
3 * Noteworthy changes in release ?.? (????-??-??) [?]
7 The GZIP environment variable is now obsolescent; gzip now warns if
8 it is used, and rejects attempts to use dangerous options or operands.
9 You can use an alias or script instead.
13 gzip now accepts the --synchronous option, which causes it to use
14 fsync and similar primitives to transfer output data to the output
15 file's storage device when the file system supports this. Although
16 this option makes gzip safer in the presence of system crashes, it
17 can make gzip considerably slower.
19 gzip now accepts the --rsyncable option. This option is accepted in
20 all modes, but has effect only when compressing: it makes the resulting
21 output more amenable to efficient use of rsync. For example, when a
22 large input file gets a small change, a gzip --rsyncable image of
23 that file will remain largely unchanged, too. Without --rsyncable,
24 even a tiny change in the input could result in a totally different
25 gzip-compressed output file.
29 gzip -k -v no longer reports that files are replaced.
30 [bug present since the beginning]
33 * Noteworthy changes in release 1.6 (2013-06-09) [stable]
37 gzip now accepts the --keep (-k) option, for consistency with tools
38 like xz, lzip and bzip2. With this option, gzip no longer removes
39 named input files when compressing or decompressing.
43 gzip -d no longer malfunctions with certain invalid data in 'pack' format.
44 [bug introduced in gzip-0.8]
46 When overwriting, gzip no longer acts as if you typed "y" when you type "n",
47 on some platforms when compiled with optimization.
48 [bug introduced in gzip-1.3.6]
50 zgrep no longer malfunctions with a multi-digit context option like -15.
51 Now, it passes that option to grep (equivalent to -C15) just as it does
52 for single-digit options. [bug introduced in gzip-1.3.12]
54 zmore now acts more like 'more', and is more portable to POSIXish hosts.
57 * Noteworthy changes in release 1.5 (2012-06-17) [stable]
61 gzip -d now decodes and checks header CRC16 checksums as specified by
62 the FHCRC section of Internet RFC 1952.
64 "gzip -d -S '' precious.gz" is now rejected immediately. Before,
65 that command would emulate "rm -i precious.gz", but with an easily-
66 misunderstood prompt. I.e., gzip would ask if it's ok to remove the
67 existing file, "precious.gz". If you made the mistake of saying "yes",
68 it would remove that input file before attempting to uncompress it.
70 gzip -cdf now properly handles input consisting of gzip'd data followed
71 by uncompressed data. Before it would output raw compressed input, too.
72 For example, now "(printf x|gzip; echo y)|gzip -dcf" prints "xy\n",
73 while before it would print "x<compressed data>y\n".
75 gzip -rf no longer compresses files more than once (e.g., replacing
76 FOO with FOO.gz.gz) on file systems such as ZFS where a readdir
77 loop that unlinks and creates files can revisit output files.
80 * Noteworthy changes in release 1.4 (2010-01-20) [stable]
84 gzip -d could segfault and/or clobber the stack, possibly leading to
85 arbitrary code execution. This affects x86_64 but not 32-bit systems.
86 This fixes CVE-2010-0001.
87 For more details, see http://bugzilla.redhat.com/554418
89 gzip -d would fail with a CRC error for some valid inputs.
90 So far, the only valid input known to exhibit this failure was
91 compressed "from FAT filesystem (MS-DOS, OS/2, NT)". In addition,
92 to trigger the failure, your memcpy implementation must copy in
96 * Noteworthy changes in release 1.3.14 (2009-10-30) [beta]
100 gzip no longer fails when there is exactly one trailing NUL byte
101 gzip has always accepted trailing NUL bytes. Note the plural.
103 zdiff would exit with status 2 (indicating an error) rather than 1 to
104 indicate differences when both inputs were compressed and different.
106 zdiff would fail to print differences in two compressed inputs
108 zgrep -f - didn't work
111 * Noteworthy changes in release 1.3.13 (2009-09-30) [stable]
113 ** 'gzip -f foo.gz' now creates a file foo.gz.gz instead of complaining.
117 gzip -d no longer fails with "-" as 2nd or subsequent argument
119 gzip no longer ignores a close-induced write failure, e.g., on NFS
121 gzip -d no longer segfaults on certain invalid inputs
124 Major changes in Gzip 1.3.12 (2007-04-13)
126 * znew now uses $TMPDIR (default /tmp) instead of always using /tmp.
128 * It is now documented that gzip ignores case when examining file name
129 extensions; for example, 'gzip test.Gz' (without -f) fails because
130 the file name ends in '.Gz'.
132 Major changes in Gzip 1.3.11 (2007-02-05)
134 * As per the GNU coding standards, the behavior of gzip and its
135 companion executables no longer depend on the name used to invoke them.
136 For example, 'gzip' and 'gunzip' are no longer hard links;
137 instead, 'gunzip' is now a small program that invokes 'gzip -d'.
139 * zdiff now checks for subsidiary gzip failures, and works around
140 bugs in IRIX 6 sh, Tru64 4.0F ksh, and Solaris 8 bash.
142 Major changes in Gzip 1.3.10 (2006-12-30)
144 * gzip -c and zcat now work on special files, files with special mode bits,
145 and files with multiple hard links.
146 * gzip -q now exits with status 2 (not 1) when SIGPIPE is received.
147 * zcmp and zdiff did not work in the usual case, due to a typo.
148 * zgrep has many bugs fixed with argument handling, special characters,
150 * zless no longer mishandles $%=~ in file names.
152 Gzip 1.3.9 (2006-12-15)
154 * No major changes; only porting fixes.
156 Major changes in Gzip 1.3.8 (2006-12-08)
158 * Fix some gzip problems:
159 - A security fix from Debian 1.3.5-5 was inadvertently omitted.
160 - The assembler is now invoked with --noexecstack if supported,
161 so that gzip can better resist stack-smashing attacks.
163 Major changes in Gzip 1.3.7 (2006-12-06)
165 * Fix some gzip problems:
166 - Refuse to compress setuid or setgid files, or files with the sticky bit.
167 - Fix more race conditions in setting file permissions and owner,
168 removing output files, following symbolic links, and dealing with
170 - Remove most of the code working around ENAMETOOLONG deficiencies.
171 Systems with those deficiencies are long-dead, and the workarounds
172 had race conditions on modern hosts.
173 - Catch CPU time and file size limit signals, too.
174 - Check for read errors when closing files.
175 - Fix a core dump caused by a stray abort mistakenly introduced in 1.3.6.
176 * Fix some gzexe problems:
177 - Improve resistance to denial-of-service attacks.
178 - Fix some quoting and escaping bugs.
179 - Do not assume /tmp is sticky (though it should be!).
180 - Do not assume the working directory can be written.
181 - Rely on PATH in the generated executable, as the man page says.
182 - Don't assume IFS is sane.
183 - Exit with signal's status, if signaled.
185 Major changes in Gzip 1.3.6 (2006-11-20)
187 * Fix some race conditions in setting file time stamps, permissions, and owner.
188 * Fix some race conditions in signal handling.
189 * When gzip exits due to a signal, it exits with the signal's status, not 1.
190 * gzip now restores file time stamps to the resolution supported by the
191 time-setting primitives of the operating system, typically 1 microsecond.
192 Formerly it restored them only to the nearest second.
193 * gzip -r no longer attempts to reset the last-access times of directories
194 it reads, as this messes up when other processes are reading the directories.
195 * The options --version and --help now work on all gzip-installed executables,
196 and now use a format similar to other GNU programs.
197 * The manual is now distributed under the terms of the GNU Free
198 Documentation License without invariant sections or cover texts.
199 * Port to current versions of Autoconf, Automake, and Gnulib.
201 Major changes from 1.3.4 to 1.3.5
202 * gzip now removes any output symlink before writing output file.
203 * zgrep etc. scripts now port to POSIX 1003.1-2001 hosts.
204 * zforce no longer assumes 14-byte file name length limit.
205 * zless is now implemented using less and LESSOPEN, not zmore and PAGER.
206 * assembly-language speedups reenabled; were mistakenly disabled in 1.3.
208 Major changes from 1.3.3 to 1.3.4
209 * Less output is lost when decompressing a truncated file.
210 * The manual is now distributed under the terms of the GNU Free
211 Documentation License.
213 No major changes in 1.3.2 or 1.3.3 (bug fixes only)
215 Major changes from 1.3 to 1.3.1
216 * zgrep now supports --, -H, -h, -L, -l, -C, -d, -m and their long equivalents.
218 Major changes from 1.2.4 to 1.3
219 * Add support for large files, e.g. files larger than 2 GB on Solaris 2.6.
220 * Adjust file size listing format for files larger than 10 GB.
221 * New command `zless'.
222 * `zdiff' now reports exit status like `diff' does.
223 * `zcat' is now always called `zcat', not `gzcat'.
224 Similarly for `zdiff', `zgrep', `zmore', `znew', `zforce'.
225 * Warn about a compressed file's trailing zeros only if verbose,
226 for compatibility with recent versions of GNU tar.
227 * Conform to changes to GNU makefile standards.
228 * Port to Autoconf 2.13.
229 * Convert to Automake.
230 * Fix bugs in the following areas:
231 - files larger than 4 GB
232 - security hole involving symlinks from /tmp
233 - security hole involving long file names
234 - permissions bug when compressing a symbolic link to a file
236 - concatenated compressed files on INBUFSIZ boundaries
237 - porting bugs on hosts with signed chars
238 - porting bug with upper and lower case
239 - porting bug for hosts that reserve the names `basename' or `warning'
241 Major changes from 1.2.3 to 1.2.4
242 * By default, do not restore file name and timestamp from those saved
243 inside the .gz file (behave as 'compress'). Added the --name option
244 to force name and timestamp restoration.
245 * Accept - as synonym for stdin.
246 * Use manlinks=so or ln to support either hard links or .so in man pages
247 * Accept foo.gz~ in zdiff.
248 * Added support for Windows NT
249 * Handle ENAMETOOLONG for strict Posix systems
250 * Use --recursive instead of --recurse to comply with Webster and
252 * Allow installation of shell scripts with a g prefix: make G=g install
253 * Install by default zcat as gzcat if gzcat already exists in path.
254 * Let zmore behave as more when invoked without parameters (give help)
255 * Let gzip --list reject files not in gzip format even with --force.
256 * Don't complain about non gzip files for options -rt or -rl.
257 * Added advice in INSTALL for several systems.
259 Major changes from 1.2.2 to 1.2.3
260 * Don't display the output name when decompressing except with --verbose.
261 * Remove usage of alloca in getopt.c and all makefiles.
262 * Added the zfile shell script in subdirectory sample.
263 * Moved the list of compiler bugs from README to INSTALL.
264 * Added vms/Readme.vms.
266 Major changes from 1.2.1 to 1.2.2
267 * Fix a compilation error on Sun with cc (worked with gcc).
269 Major changes from 1.2 to 1.2.1
270 * Let zmore act as more if the data is not gzipped.
271 * made gzexe more secure (don't rely on PATH).
272 * By default, display output name only when the name was actually truncated.
274 Major changes from 1.1.2 to 1.2
275 * Added the --list option to display the file characteristics.
276 * Added the --no-name option: do not save or restore original filename
277 Save the original name by default.
278 * Allow gunzip --suffix "" to attempt decompression on any file
279 regardless of its extension if an original name is present.
280 * Add support for the SCO compress -H format.
281 * gzip --fast now compresses faster (speed close to that of compress)
282 with degraded compression ratio (but still better than compress).
283 Default level changed to -6 (acts exactly as previous level -5) to
284 be a better indication of its placement in the speed/ratio range.
285 * Use smart name truncation: 123456789012.c -> 123456789.c.gz
286 instead of 12345678901.gz
287 * With --force, let zcat pass non gzip'ed data unchanged (zcat == cat)
288 * Added the zgrep shell script.
289 * Made sub.c useful for 16 bit sound, 24 bit images, etc..
290 * Suppress warnings about suffix for gunzip -r, except with --verbose.
291 * On MSDOS, use .gz extension when possible (files without extension)
292 * Moved the sample programs to a subdirectory sample.
293 * Added a "Special targets" section in INSTALL.
295 Major changes from 1.1.1 to 1.1.2.
296 * Fix serious bug for VMS (-gz not removed when decompressing).
297 * Allow suffix other than .gz in znew.
298 * Do not display compression ratio when decompressing stdin.
299 * In zmore.in, work around brain damaged stty -g (Ultrix).
300 * Display a correct compression ratio for .Z files.
301 * Added .z to .gz renaming script in INTALL.
302 * Allow setting CFLAGS in configure.
304 Major changes from 1.1 to 1.1.1.
305 * Fix serious bug in vms.c (affects Vax/VMS only).
306 * Added --ascii option.
307 * Add workaround in configure.in for Ultrix (quote eval argument)
309 Major changes from 1.0.7 to 1.1.
310 * Use .gz suffix by default, add --suffix option.
311 * Let gunzip accept a "_z" suffix (used by one 'compress' on Vax/VMS).
312 * Quit when reading garbage from stdin instead of reporting an error.
313 * Added makefile for VAX/MMS and support for wildcards on VMS.
314 * Added support for MSC under OS/2.
315 * Added support for Prime/PRIMOS.
316 * Display compression ratio also when decompressing (with --verbose).
317 * Quit after --version (GNU standard)
318 * Use --force to bypass isatty() check
319 * Continue processing other files in case of recoverable error.
320 * Added comparison of zip and gzip in the readme file.
321 * Added small sample programs (ztouch, sub, add)
322 * Use less memory when compiled with -DSMALL_MEM (for MSDOS).
323 * Remove the "off by more than one minute" time stamp kludge
325 Major changes from 1.0.6 to 1.0.7.
326 * Allow zmore to read from standard input (like more).
327 * Support the 68000 (Atari ST) in match.S.
328 * Retry partial writes (required on Linux when gzip is suspended in a pipe).
329 * Allow full pathnames and renamings in gzexe.
330 * Don't let gzexe compress setuid executables or gzip itself.
331 * Added vms/Makefile.gcc for gcc on the Vax.
332 * Allow installation of binaries and shell scripts in different dirs.
333 * Allows complex PAGER variable in zmore (e.g.: PAGER="col -x | more")
334 * Allow installation of zcat as gzcat.
335 * Several small changes for portability to old or weird systems.
336 * Suppress help message and send compressed data to the terminal when
337 gzip is invoked without parameters and without redirection.
338 * Add compile option GNU_STANDARD to respect the GNU coding standards:
339 with -DGNU_STANDARD, behave as gzip even if invoked under the name gunzip.
340 (I don't like the last two changes, which were requested by the FSF.)
342 Major changes from 1.0.5 to 1.0.6.
343 * Let gzexe detect executables that are already gzexe'd.
344 * Keep file attributes in znew and gzexe if cpmod is available.
345 * Don't try restoring record format on VMS (1.0.5 did not work correctly)
346 * Added asm version for 68000 in amiga/match.a.
347 Use asm version for Atari TT and NeXT.
348 * For OS/2, assume HPFS by default, add flag OS2FAT if necessary.
349 * Fixed some bugs in zdiff and define zcmp as a link to zdiff.
352 Major changes from 1.0.4 to 1.0.5.
353 * For VMS, restore the file type for variable record format, otherwise
354 extract in fixed length format (not perfect, but better than
355 forcing all files to be in stream_LF format).
356 * For VMS, use "-z" default suffix and accept a version number in file names.
357 * For Unix, allow compression of files with name ending in 'z'. Use only
358 .z, .*-z, .tgz, .taz as valid gzip extensions. In the last two cases,
359 extract to .tar by default.
360 * On some versions of MSDOS, files with a 3 character extension could not
362 * Garbage collect files in /tmp created by gzexe.
363 * Fix the 'OS code' byte in the gzip header.
364 * For the Amiga, add the missing utime.h and add support for gcc.
367 Major changes from 1.0.3 to 1.0.4.
368 * Added optimized asm version for 68020.
369 * Add support for DJGPP.
371 * Add support for the Atari ST.
372 * Added zforce to rename gzip'ed files with truncated names.
373 * Do not install with name uncompress (some systems rely on the
374 absence of any check in the old uncompress).
375 * Added missing function (fcfree) in msdos/tailor.c
376 * Let gunzip handle .tgz files, and let gzip skip them.
377 * Added -d option (decompress) for gzexe and try preserving file permissions.
378 * Suppress all warnings with -q.
379 * Use GZIP_OPT for VMS to avoid conflict with program name.
380 * ... and many other small changes (see ChangeLog)
383 Major changes from 1.0.2 to 1.0.3
384 * Added -K option for znew to keep old .Z files if smaller
385 * Added -q option (quiet) to cancel -v in GZIP env variable.
386 * Made gzexe safer on systems with filename limitation to 14 chars.
387 * Fixed bugs in handling of GZIP env variable and incorrect free with Turbo C.
390 Major changes from 1.0.1 to 1.0.2
391 * Added env variable GZIP for default options. Example:
392 for sh: GZIP="-8 -v"; export GZIP
393 for csh: setenv GZIP "-8 -v"
394 * Added support for the Amiga.
395 * znew now keeps the old .Z if it is smaller than the .z file.
396 This can happen for some large and very redundant files.
397 * Do not complain about trailing garbage for record oriented IO (Vax/VMS).
398 This implies however that multi-part gzip files are not supported
400 * Added gzexe to compress rarely used executables.
401 * Reduce memory usage (required for MSDOS and useful on all systems).
402 * Preserve time stamp in znew -P (pipe option) if touch -r works.
405 Major changes from 1.0 to 1.0.1
406 * fix trivial errors in the Borland makefile (msdos/Makefile.bor)
409 Major changes from 0.8.2 to 1.0
410 * gzip now runs on Vax/VMS
411 * gzip will not not overwrite files without -f when using /bin/sh in
413 * Support the test option -t for compressed (.Z) files.
414 Allow some data recovery for bad .Z files.
415 * Added makefiles for MSDOS (Only tested for MSC, not Borland).
416 * still more changes to configure for several systems
419 Major changes from 0.8.1 to 0.8.2:
420 * yet more changes to configure for Linux and other systems
421 * Allow zcat on a file with multiple links.
424 Major changes from 0.8 to 0.8.1:
425 * znew has now a pipe option -P to reduce the disk space requirements,
426 but this option does not preserve timestamps.
427 * Fixed some #if directives for compilation with TurboC.
430 Major changes from 0.7 to 0.8:
431 * gzip can now extract .z files created by 'pack'.
432 * configure should no longer believe that every machine is a 386
433 * Fix the entry for /etc/magic in INSTALL.
434 * Add patch for GNU tar 1.11.1 and a pointer to crypt++.el
435 * Uncompress files with multiple links only with -f.
436 * Fix for uncompress of .Z files on 16-bit machines
437 * Create a correct output name for file names of exactly N-1 chars when
438 the system has a limit of N chars.
441 Major changes from 0.6 to 0.7:
442 * Use "make check" instead of "make test".
443 * Keep time stamp and pass options to gzip in znew.
444 * Do not create .z.z files with gzip -r.
445 * Allow again gunzip .zip files (was working in 0.5)
446 * Allow again compilation with TurboC 2.0 (was working in 0.4)
449 Major changes form 0.5 to 0.6:
450 * gunzip reported an error when extracting certain .z files. The .z files
451 produced by gzip 0.5 are correct and can be read by gunzip 0.6.
452 * gunzip now supports multiple compressed members within a single .z file.
453 * Fix the check for i386 in configure.
454 * Added "make test" to check for compiler bugs. (gcc -finline-functions
455 is broken at least on the NeXT.)
456 * Use environment variable PAGER in zmore if it is defined.
457 * Accept gzcat in addition to zcat for people having /usr/bin before
458 /usr/local/bin in their path.
461 ========================================================================
463 Copyright (C) 1999, 2001-2002, 2006-2007, 2009-2016 Free Software Foundation,
465 Copyright (C) 1992, 1993 Jean-loup Gailly
467 Permission is granted to copy, distribute and/or modify this document
468 under the terms of the GNU Free Documentation License, Version 1.3 or
469 any later version published by the Free Software Foundation; with no
470 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
471 Texts. A copy of the license is included in the ``GNU Free
472 Documentation License'' file as part of this distribution.