1 GNU gzip NEWS -*- outline -*-
3 * Noteworthy changes in release 1.9 (2018-01-07) [stable]
7 gzip -d -S SUFFIX file.SUFFIX would fail for any upper-case byte in SUFFIX.
8 E.g., before, this command would fail:
9 $ :|gzip > kT && gzip -d -S T kT
10 gzip: kT: unknown suffix -- ignored
11 [bug present since the beginning]
13 When decompressing data in 'pack' format, gzip no longer mishandles
14 leading zeros in the end-of-block code. [bug introduced in gzip-1.6]
16 When converting from system-dependent time_t format to the 32-bit
17 unsigned MTIME format used in gzip files, if a timestamp does not
18 fit gzip now substitutes zero instead of the timestamp's low-order
19 32 bits, as per Internet RFC 1952. When converting from MTIME to
20 time_t format, if a timestamp does not fit gzip now warns and
21 substitutes the nearest in-range value instead of crashing or
22 silently substituting an implementation-defined value (typically,
23 the timestamp's low-order bits). This affects timestamps before
24 1970 and after 2106, and timestamps after 2038 on platforms with
25 32-bit signed time_t. [bug present since the beginning]
27 Commands implemented via shell scripts are now more consistent about
28 failure status. For example, 'gunzip --help >/dev/full' now
29 consistently exits with status 1 (error), instead of with status 2
30 (warning) on some platforms. [bug present since the beginning]
32 Support for VMS and Amiga has been removed. It was not working anyway,
33 and it reportedly caused file name glitches on MS-Windowsish platforms.
36 * Noteworthy changes in release 1.8 (2016-04-26) [stable]
40 gzip -l no longer falsely reports a write error when writing to a pipe.
41 [bug introduced in gzip-1.7]
43 Port to Oracle Solaris Studio 12 on x86-64.
44 [bug present since at least gzip-1.2.4]
46 When configuring gzip, ./configure DEFS='...-DNO_ASM...' now
47 suppresses assembler again. [bug introduced in gzip-1.3.5]
50 * Noteworthy changes in release 1.7 (2016-03-27) [stable]
52 ** Changes in behavior
54 The GZIP environment variable is now obsolescent; gzip now warns if
55 it is used, and rejects attempts to use dangerous options or operands.
56 You can use an alias or script instead.
58 Installed programs like 'zgrep' now use the PATH environment variable
59 as usual to find subsidiary programs like 'gzip' and 'grep'.
60 Previously they prepended the installation directory to the PATH,
61 which sometimes caused 'make check' to test the wrong gzip executable.
62 [bug introduced in gzip-1.3.13]
66 gzip now accepts the --synchronous option, which causes it to use
67 fsync and similar primitives to transfer output data to the output
68 file's storage device when the file system supports this. Although
69 this option makes gzip safer in the presence of system crashes, it
70 can make gzip considerably slower.
72 gzip now accepts the --rsyncable option. This option is accepted in
73 all modes, but has effect only when compressing: it makes the resulting
74 output more amenable to efficient use of rsync. For example, when a
75 large input file gets a small change, a gzip --rsyncable image of
76 that file will remain largely unchanged, too. Without --rsyncable,
77 even a tiny change in the input could result in a totally different
78 gzip-compressed output file.
82 gzip -k -v no longer reports that files are replaced.
83 [bug present since the beginning]
85 zgrep -f A B C no longer reads A more than once if A is not a regular file.
86 This better supports invocations like 'zgrep -f <(COMMAND) B C' in Bash.
87 [bug introduced in gzip-1.2]
90 * Noteworthy changes in release 1.6 (2013-06-09) [stable]
94 gzip now accepts the --keep (-k) option, for consistency with tools
95 like xz, lzip and bzip2. With this option, gzip no longer removes
96 named input files when compressing or decompressing.
100 gzip -d no longer malfunctions with certain invalid data in 'pack' format.
101 [bug introduced in gzip-0.8]
103 When overwriting, gzip no longer acts as if you typed "y" when you type "n",
104 on some platforms when compiled with optimization.
105 [bug introduced in gzip-1.3.6]
107 zgrep no longer malfunctions with a multi-digit context option like -15.
108 Now, it passes that option to grep (equivalent to -C15) just as it does
109 for single-digit options. [bug introduced in gzip-1.3.12]
111 zmore now acts more like 'more', and is more portable to POSIXish hosts.
114 * Noteworthy changes in release 1.5 (2012-06-17) [stable]
118 gzip -d now decodes and checks header CRC16 checksums as specified by
119 the FHCRC section of Internet RFC 1952.
121 "gzip -d -S '' precious.gz" is now rejected immediately. Before,
122 that command would emulate "rm -i precious.gz", but with an easily-
123 misunderstood prompt. I.e., gzip would ask if it's ok to remove the
124 existing file, "precious.gz". If you made the mistake of saying "yes",
125 it would remove that input file before attempting to uncompress it.
127 gzip -cdf now properly handles input consisting of gzip'd data followed
128 by uncompressed data. Before it would output raw compressed input, too.
129 For example, now "(printf x|gzip; echo y)|gzip -dcf" prints "xy\n",
130 while before it would print "x<compressed data>y\n".
132 gzip -rf no longer compresses files more than once (e.g., replacing
133 FOO with FOO.gz.gz) on file systems such as ZFS where a readdir
134 loop that unlinks and creates files can revisit output files.
137 * Noteworthy changes in release 1.4 (2010-01-20) [stable]
141 gzip -d could segfault and/or clobber the stack, possibly leading to
142 arbitrary code execution. This affects x86_64 but not 32-bit systems.
143 This fixes CVE-2010-0001.
144 For more details, see https://bugzilla.redhat.com/554418
146 gzip -d would fail with a CRC error for some valid inputs.
147 So far, the only valid input known to exhibit this failure was
148 compressed "from FAT filesystem (MS-DOS, OS/2, NT)". In addition,
149 to trigger the failure, your memcpy implementation must copy in
153 * Noteworthy changes in release 1.3.14 (2009-10-30) [beta]
157 gzip no longer fails when there is exactly one trailing NUL byte
158 gzip has always accepted trailing NUL bytes. Note the plural.
160 zdiff would exit with status 2 (indicating an error) rather than 1 to
161 indicate differences when both inputs were compressed and different.
163 zdiff would fail to print differences in two compressed inputs
165 zgrep -f - didn't work
168 * Noteworthy changes in release 1.3.13 (2009-09-30) [stable]
170 ** 'gzip -f foo.gz' now creates a file foo.gz.gz instead of complaining.
174 gzip -d no longer fails with "-" as 2nd or subsequent argument
176 gzip no longer ignores a close-induced write failure, e.g., on NFS
178 gzip -d no longer segfaults on certain invalid inputs
181 Major changes in Gzip 1.3.12 (2007-04-13)
183 * znew now uses $TMPDIR (default /tmp) instead of always using /tmp.
185 * It is now documented that gzip ignores case when examining file name
186 extensions; for example, 'gzip test.Gz' (without -f) fails because
187 the file name ends in '.Gz'.
189 Major changes in Gzip 1.3.11 (2007-02-05)
191 * As per the GNU coding standards, the behavior of gzip and its
192 companion executables no longer depend on the name used to invoke them.
193 For example, 'gzip' and 'gunzip' are no longer hard links;
194 instead, 'gunzip' is now a small program that invokes 'gzip -d'.
196 * zdiff now checks for subsidiary gzip failures, and works around
197 bugs in IRIX 6 sh, Tru64 4.0F ksh, and Solaris 8 bash.
199 Major changes in Gzip 1.3.10 (2006-12-30)
201 * gzip -c and zcat now work on special files, files with special mode bits,
202 and files with multiple hard links.
203 * gzip -q now exits with status 2 (not 1) when SIGPIPE is received.
204 * zcmp and zdiff did not work in the usual case, due to a typo.
205 * zgrep has many bugs fixed with argument handling, special characters,
207 * zless no longer mishandles $%=~ in file names.
209 Gzip 1.3.9 (2006-12-15)
211 * No major changes; only porting fixes.
213 Major changes in Gzip 1.3.8 (2006-12-08)
215 * Fix some gzip problems:
216 - A security fix from Debian 1.3.5-5 was inadvertently omitted.
217 - The assembler is now invoked with --noexecstack if supported,
218 so that gzip can better resist stack-smashing attacks.
220 Major changes in Gzip 1.3.7 (2006-12-06)
222 * Fix some gzip problems:
223 - Refuse to compress setuid or setgid files, or files with the sticky bit.
224 - Fix more race conditions in setting file permissions and owner,
225 removing output files, following symbolic links, and dealing with
227 - Remove most of the code working around ENAMETOOLONG deficiencies.
228 Systems with those deficiencies are long-dead, and the workarounds
229 had race conditions on modern hosts.
230 - Catch CPU time and file size limit signals, too.
231 - Check for read errors when closing files.
232 - Fix a core dump caused by a stray abort mistakenly introduced in 1.3.6.
233 * Fix some gzexe problems:
234 - Improve resistance to denial-of-service attacks.
235 - Fix some quoting and escaping bugs.
236 - Do not assume /tmp is sticky (though it should be!).
237 - Do not assume the working directory can be written.
238 - Rely on PATH in the generated executable, as the man page says.
239 - Don't assume IFS is sane.
240 - Exit with signal's status, if signaled.
242 Major changes in Gzip 1.3.6 (2006-11-20)
244 * Fix some race conditions in setting file timestamps, permissions, and owner.
245 * Fix some race conditions in signal handling.
246 * When gzip exits due to a signal, it exits with the signal's status, not 1.
247 * gzip now restores file timestamps to the resolution supported by the
248 time-setting primitives of the operating system, typically 1 microsecond.
249 Formerly it restored them only to the nearest second.
250 * gzip -r no longer attempts to reset the last-access times of directories
251 it reads, as this messes up when other processes are reading the directories.
252 * The options --version and --help now work on all gzip-installed executables,
253 and now use a format similar to other GNU programs.
254 * The manual is now distributed under the terms of the GNU Free
255 Documentation License without invariant sections or cover texts.
256 * Port to current versions of Autoconf, Automake, and Gnulib.
258 Major changes from 1.3.4 to 1.3.5
259 * gzip now removes any output symlink before writing output file.
260 * zgrep etc. scripts now port to POSIX 1003.1-2001 hosts.
261 * zforce no longer assumes 14-byte file name length limit.
262 * zless is now implemented using less and LESSOPEN, not zmore and PAGER.
263 * assembly-language speedups reenabled; were mistakenly disabled in 1.3.
265 Major changes from 1.3.3 to 1.3.4
266 * Less output is lost when decompressing a truncated file.
267 * The manual is now distributed under the terms of the GNU Free
268 Documentation License.
270 No major changes in 1.3.2 or 1.3.3 (bug fixes only)
272 Major changes from 1.3 to 1.3.1
273 * zgrep now supports --, -H, -h, -L, -l, -C, -d, -m and their long equivalents.
275 Major changes from 1.2.4 to 1.3
276 * Add support for large files, e.g. files larger than 2 GB on Solaris 2.6.
277 * Adjust file size listing format for files larger than 10 GB.
278 * New command `zless'.
279 * `zdiff' now reports exit status like `diff' does.
280 * `zcat' is now always called `zcat', not `gzcat'.
281 Similarly for `zdiff', `zgrep', `zmore', `znew', `zforce'.
282 * Warn about a compressed file's trailing zeros only if verbose,
283 for compatibility with recent versions of GNU tar.
284 * Conform to changes to GNU makefile standards.
285 * Port to Autoconf 2.13.
286 * Convert to Automake.
287 * Fix bugs in the following areas:
288 - files larger than 4 GB
289 - security hole involving symlinks from /tmp
290 - security hole involving long file names
291 - permissions bug when compressing a symbolic link to a file
293 - concatenated compressed files on INBUFSIZ boundaries
294 - porting bugs on hosts with signed chars
295 - porting bug with upper and lower case
296 - porting bug for hosts that reserve the names `basename' or `warning'
298 Major changes from 1.2.3 to 1.2.4
299 * By default, do not restore file name and timestamp from those saved
300 inside the .gz file (behave as 'compress'). Added the --name option
301 to force name and timestamp restoration.
302 * Accept - as synonym for stdin.
303 * Use manlinks=so or ln to support either hard links or .so in man pages
304 * Accept foo.gz~ in zdiff.
305 * Added support for Windows NT
306 * Handle ENAMETOOLONG for strict Posix systems
307 * Use --recursive instead of --recurse to comply with Webster and
309 * Allow installation of shell scripts with a g prefix: make G=g install
310 * Install by default zcat as gzcat if gzcat already exists in path.
311 * Let zmore behave as more when invoked without parameters (give help)
312 * Let gzip --list reject files not in gzip format even with --force.
313 * Don't complain about non gzip files for options -rt or -rl.
314 * Added advice in INSTALL for several systems.
316 Major changes from 1.2.2 to 1.2.3
317 * Don't display the output name when decompressing except with --verbose.
318 * Remove usage of alloca in getopt.c and all makefiles.
319 * Added the zfile shell script in subdirectory sample.
320 * Moved the list of compiler bugs from README to INSTALL.
321 * Added vms/Readme.vms.
323 Major changes from 1.2.1 to 1.2.2
324 * Fix a compilation error on Sun with cc (worked with gcc).
326 Major changes from 1.2 to 1.2.1
327 * Let zmore act as more if the data is not gzipped.
328 * made gzexe more secure (don't rely on PATH).
329 * By default, display output name only when the name was actually truncated.
331 Major changes from 1.1.2 to 1.2
332 * Added the --list option to display the file characteristics.
333 * Added the --no-name option: do not save or restore original filename
334 Save the original name by default.
335 * Allow gunzip --suffix "" to attempt decompression on any file
336 regardless of its extension if an original name is present.
337 * Add support for the SCO compress -H format.
338 * gzip --fast now compresses faster (speed close to that of compress)
339 with degraded compression ratio (but still better than compress).
340 Default level changed to -6 (acts exactly as previous level -5) to
341 be a better indication of its placement in the speed/ratio range.
342 * Use smart name truncation: 123456789012.c -> 123456789.c.gz
343 instead of 12345678901.gz
344 * With --force, let zcat pass non gzip'ed data unchanged (zcat == cat)
345 * Added the zgrep shell script.
346 * Made sub.c useful for 16 bit sound, 24 bit images, etc..
347 * Suppress warnings about suffix for gunzip -r, except with --verbose.
348 * On MSDOS, use .gz extension when possible (files without extension)
349 * Moved the sample programs to a subdirectory sample.
350 * Added a "Special targets" section in INSTALL.
352 Major changes from 1.1.1 to 1.1.2.
353 * Fix serious bug for VMS (-gz not removed when decompressing).
354 * Allow suffix other than .gz in znew.
355 * Do not display compression ratio when decompressing stdin.
356 * In zmore.in, work around brain damaged stty -g (Ultrix).
357 * Display a correct compression ratio for .Z files.
358 * Added .z to .gz renaming script in INTALL.
359 * Allow setting CFLAGS in configure.
361 Major changes from 1.1 to 1.1.1.
362 * Fix serious bug in vms.c (affects Vax/VMS only).
363 * Added --ascii option.
364 * Add workaround in configure.in for Ultrix (quote eval argument)
366 Major changes from 1.0.7 to 1.1.
367 * Use .gz suffix by default, add --suffix option.
368 * Let gunzip accept a "_z" suffix (used by one 'compress' on Vax/VMS).
369 * Quit when reading garbage from stdin instead of reporting an error.
370 * Added makefile for VAX/MMS and support for wildcards on VMS.
371 * Added support for MSC under OS/2.
372 * Added support for Prime/PRIMOS.
373 * Display compression ratio also when decompressing (with --verbose).
374 * Quit after --version (GNU standard)
375 * Use --force to bypass isatty() check
376 * Continue processing other files in case of recoverable error.
377 * Added comparison of zip and gzip in the readme file.
378 * Added small sample programs (ztouch, sub, add)
379 * Use less memory when compiled with -DSMALL_MEM (for MSDOS).
380 * Remove the "off by more than one minute" timestamp kludge
382 Major changes from 1.0.6 to 1.0.7.
383 * Allow zmore to read from standard input (like more).
384 * Support the 68000 (Atari ST) in match.S.
385 * Retry partial writes (required on Linux when gzip is suspended in a pipe).
386 * Allow full pathnames and renamings in gzexe.
387 * Don't let gzexe compress setuid executables or gzip itself.
388 * Added vms/Makefile.gcc for gcc on the Vax.
389 * Allow installation of binaries and shell scripts in different dirs.
390 * Allows complex PAGER variable in zmore (e.g.: PAGER="col -x | more")
391 * Allow installation of zcat as gzcat.
392 * Several small changes for portability to old or weird systems.
393 * Suppress help message and send compressed data to the terminal when
394 gzip is invoked without parameters and without redirection.
395 * Add compile option GNU_STANDARD to respect the GNU coding standards:
396 with -DGNU_STANDARD, behave as gzip even if invoked under the name gunzip.
397 (I don't like the last two changes, which were requested by the FSF.)
399 Major changes from 1.0.5 to 1.0.6.
400 * Let gzexe detect executables that are already gzexe'd.
401 * Keep file attributes in znew and gzexe if cpmod is available.
402 * Don't try restoring record format on VMS (1.0.5 did not work correctly)
403 * Added asm version for 68000 in amiga/match.a.
404 Use asm version for Atari TT and NeXT.
405 * For OS/2, assume HPFS by default, add flag OS2FAT if necessary.
406 * Fixed some bugs in zdiff and define zcmp as a link to zdiff.
409 Major changes from 1.0.4 to 1.0.5.
410 * For VMS, restore the file type for variable record format, otherwise
411 extract in fixed length format (not perfect, but better than
412 forcing all files to be in stream_LF format).
413 * For VMS, use "-z" default suffix and accept a version number in file names.
414 * For Unix, allow compression of files with name ending in 'z'. Use only
415 .z, .*-z, .tgz, .taz as valid gzip extensions. In the last two cases,
416 extract to .tar by default.
417 * On some versions of MSDOS, files with a 3 character extension could not
419 * Garbage collect files in /tmp created by gzexe.
420 * Fix the 'OS code' byte in the gzip header.
421 * For the Amiga, add the missing utime.h and add support for gcc.
424 Major changes from 1.0.3 to 1.0.4.
425 * Added optimized asm version for 68020.
426 * Add support for DJGPP.
428 * Add support for the Atari ST.
429 * Added zforce to rename gzip'ed files with truncated names.
430 * Do not install with name uncompress (some systems rely on the
431 absence of any check in the old uncompress).
432 * Added missing function (fcfree) in msdos/tailor.c
433 * Let gunzip handle .tgz files, and let gzip skip them.
434 * Added -d option (decompress) for gzexe and try preserving file permissions.
435 * Suppress all warnings with -q.
436 * Use GZIP_OPT for VMS to avoid conflict with program name.
437 * ... and many other small changes (see ChangeLog)
440 Major changes from 1.0.2 to 1.0.3
441 * Added -K option for znew to keep old .Z files if smaller
442 * Added -q option (quiet) to cancel -v in GZIP env variable.
443 * Made gzexe safer on systems with filename limitation to 14 chars.
444 * Fixed bugs in handling of GZIP env variable and incorrect free with Turbo C.
447 Major changes from 1.0.1 to 1.0.2
448 * Added env variable GZIP for default options. Example:
449 for sh: GZIP="-8 -v"; export GZIP
450 for csh: setenv GZIP "-8 -v"
451 * Added support for the Amiga.
452 * znew now keeps the old .Z if it is smaller than the .z file.
453 This can happen for some large and very redundant files.
454 * Do not complain about trailing garbage for record oriented IO (Vax/VMS).
455 This implies however that multi-part gzip files are not supported
457 * Added gzexe to compress rarely used executables.
458 * Reduce memory usage (required for MSDOS and useful on all systems).
459 * Preserve timestamp in znew -P (pipe option) if touch -r works.
462 Major changes from 1.0 to 1.0.1
463 * fix trivial errors in the Borland makefile (msdos/Makefile.bor)
466 Major changes from 0.8.2 to 1.0
467 * gzip now runs on Vax/VMS
468 * gzip will not not overwrite files without -f when using /bin/sh in
470 * Support the test option -t for compressed (.Z) files.
471 Allow some data recovery for bad .Z files.
472 * Added makefiles for MSDOS (Only tested for MSC, not Borland).
473 * still more changes to configure for several systems
476 Major changes from 0.8.1 to 0.8.2:
477 * yet more changes to configure for Linux and other systems
478 * Allow zcat on a file with multiple links.
481 Major changes from 0.8 to 0.8.1:
482 * znew has now a pipe option -P to reduce the disk space requirements,
483 but this option does not preserve timestamps.
484 * Fixed some #if directives for compilation with TurboC.
487 Major changes from 0.7 to 0.8:
488 * gzip can now extract .z files created by 'pack'.
489 * configure should no longer believe that every machine is a 386
490 * Fix the entry for /etc/magic in INSTALL.
491 * Add patch for GNU tar 1.11.1 and a pointer to crypt++.el
492 * Uncompress files with multiple links only with -f.
493 * Fix for uncompress of .Z files on 16-bit machines
494 * Create a correct output name for file names of exactly N-1 chars when
495 the system has a limit of N chars.
498 Major changes from 0.6 to 0.7:
499 * Use "make check" instead of "make test".
500 * Keep timestamp and pass options to gzip in znew.
501 * Do not create .z.z files with gzip -r.
502 * Allow again gunzip .zip files (was working in 0.5)
503 * Allow again compilation with TurboC 2.0 (was working in 0.4)
506 Major changes form 0.5 to 0.6:
507 * gunzip reported an error when extracting certain .z files. The .z files
508 produced by gzip 0.5 are correct and can be read by gunzip 0.6.
509 * gunzip now supports multiple compressed members within a single .z file.
510 * Fix the check for i386 in configure.
511 * Added "make test" to check for compiler bugs. (gcc -finline-functions
512 is broken at least on the NeXT.)
513 * Use environment variable PAGER in zmore if it is defined.
514 * Accept gzcat in addition to zcat for people having /usr/bin before
515 /usr/local/bin in their path.
518 ========================================================================
520 Copyright (C) 1999, 2001-2002, 2006-2007, 2009-2018 Free Software Foundation,
522 Copyright (C) 1992, 1993 Jean-loup Gailly
524 Permission is granted to copy, distribute and/or modify this document
525 under the terms of the GNU Free Documentation License, Version 1.3 or
526 any later version published by the Free Software Foundation; with no
527 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
528 Texts. A copy of the license is included in the ``GNU Free
529 Documentation License'' file as part of this distribution.