p7zip 16.02
===========
Homepage : http://p7zip.sourceforge.net/
p7zip is a port of the Windows programs 7z.exe and 7za.exe provided by 7-zip.
7-zip is a file archiver with the highest compression ratio.
Homepage : www.7-zip.org
7z uses plugins (7z.so and Codecs/Rar.so) to handle archives.
7za is a stand-alone executable (7za handles less archive formats than 7z).
7zr is a light stand-alone executable that supports only 7z/LZMA/BCJ/BCJ2.
Some GUI :
7zG : beta stage
7zFM : alpha stage
CAUTION :
---------
- FIRST : DO NOT USE the 7-zip format for backup purpose on Linux/Unix because :
- 7-zip does not store the owner/group of the file
On Linux/Unix, in order to backup directories you must use tar !
to backup a directory : tar cf - directory | 7za a -si directory.tar.7z
to restore your backup : 7za x -so directory.tar.7z | tar xf -
- if you want to send files and directories (not the owner of file)
to others Unix/MacOS/Windows users, you can use the 7-zip format.
example : 7za a directory.7z directory
do not use "-r" because this flag does not do what you think
do not use "directory/*" because of ".*" files
(example : "directory/*" does not match "directory/.profile")
USAGE:
------
Remark : you can replace 7za with 7z.
7za t archive.7z : tests files in the archive archive.7z
7za l archive.7z : lists all files from archive archive.7z
7za x archive.7z : extracts all files from archive archive.7z
to the current directory
7za a archive.7z file1 fileN : add files to the archive archive.7z
7za a archive.7z dir1 : add all files and subdirectories from directory
"dir1" to archive archive.7z
CAUTION : do not use the flag "-r" unless you know what you are doing ...
7za a -sfx archive.x dir1 : add all files from directory "dir1" to SFX archive
archive.x
You can also add or extract files to/from .zip or .tar archives.
You can also compress/uncompress .gz or .bz2 files.
7za a -tzip archive.zip file file2 file3
7za a -ttar archive.tar file
7za a -tgzip file.gz file
7za a -tbzip2 archive.bz2 file
You can use password for archives:
7za a -pmy_password archive.7z dir1
For .7z archive only, you can enable archive header encryption with "-mhe"
7za a -mhe=on -pmy_password archive.7z dir1
For more, see the documentation of 7za.exe in DOC/MANUAL directory
7za a -t7z -m0=lzma -mx=9 -mfb=64 -md=32m -ms=on archive.7z dir1
adds all files from directory "dir1" to archive archive.7z
using "ultra settings".
-t7z : 7z archive
-m0=lzma : lzma method
-mx=9 : level of compression = 9 (Ultra)
-mfb=64 : number of fast bytes for LZMA = 64
-md=32m : dictionary size = 32 megabytes
-ms=on : solid archive = on
To use the new codec "lzma2"
7za a -m0=lzma2 archive.7z directory
BENCHMARKS :
------------
7za b : bench LZMA codec
7z b -mm=crc : make internal crc check.
7za b "-mm=*" : test all methods
hugetlbfs (large pages) :
-------------------------
Using huges pages in Linux requires some preparations.
First, make sure your running kernel has support for hugetlbfs compiled in:
~$ grep hugetlbfs /proc/filesystems
nodev hugetlbfs
You can view your current huge page configuration like this:
~$ grep Huge /proc/meminfo
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
In this case the size of a huge page is 2 MiB.
So, if you have 2 GiB of RAM and want to reserve 512 MiB for huge pages,
you would need 256 pages.
Do the following as root:
~# echo 296 >/proc/sys/vm/nr_hugepages
~# grep Huge /proc/meminfo
HugePages_Total: 296
HugePages_Free: 296
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
Finally, make access from user space possible:
~# mkdir /hugepages
~# mount -t hugetlbfs -o rw,nosuid,nodev,noexec,noatime none /hugepages
~# chmod 1777 /hugepages
Option 1 : Now huge pages are configured.
In your shell, set the environment variable HUGETLB_PATH to the mount
point:
~$ export HUGETLB_PATH=/hugepages
or
Option 2 : Let p7zip find out the first directory with the type "hugetlbfs"
To enable huge page use in p7zip, pass the '-slp' switch to it.
Ex: 7za -slp a t.7z dir
If you want this to be a permanent setup :
- mkdir /hugepages
- add an entry to your /etc/fstab so that when you reboot your computer,
your hugetlbfs will mount automatically :
hugetlbfs /hugepages hugetlbfs rw,nosuid,nodev,noexec,noatime 0
0
- add this in your /etc/rc.local :
chmod 1777 /hugepages
echo 296 > /proc/sys/vm/nr_hugepages
optional : export HUGETLB_PATH=/hugepages
To enable huge page use in p7zip, pass the '-slp' switch to it : 7za -slp b
Remark : with current CPU : "7za -slp b" is not faster than "7za b".
If you want to see some speedup, compress at least 300MB
Ex : 7za -slp -mx=9 -a big_file.tar.7z big_file.tar
LICENSE :
---------
please read copyright file.
LIMITATIONS from 7-zip :
------------------------
- does not support uid/gid for the .tar format (so, use tar on Unix)
LIMITATIONS for Unix version only :
-----------------------------------
- can handle properly UNICODE filenames only if the environment is UTF-8.
Example : export LANG=en_US.UTF-8 ; unset LC_CTYPE
Remark : see the possible values for LANG in the directory
- /usr/lib/locale : Fedora 2 / Solaris 8
- /usr/share/locale : OpenBSD / Debian / FreeBSD / MacOS X /
Mandrake 10.1 / NetBSD
On Linux, to display the available locales : locale -a
p7zip relies on LC_CTYPE and then on LANG to convert name to/from UNICODE.
the command "locale" should display these environment variables.
you can also do "echo $LC_CTYPE" and "echo $LANG".
If you do not plan to export your archive, you can use the flag "-no-utf16".
Usage :
7za a -no-utf16 archive.7z dirOrFile1 ... dirOrFileN
7za t -no-utf16 archive.7z
7za l -no-utf16 archive.7z
7za x -no-utf16 archive.7z
- ignores Windows file access permissions (files are created with default
permissions)
see also TODO file.
DEVELOPPER CORNER:
------------------
- static analysis with cppcheck
make cppcheck
- static analysis with clang
scan-build make all4 2>&1 | tee -i scan-build.out
- dynamic analysis : valgrind
cp makefile.linux_valgrind makefile.machine
make test
- dynamic analysis : gcc sanitize
cp makefile.linux_amd64_sanitizer makefile.machine
make test
- WaitForMultipleObject has no equivalence on Unix.
- Events don't exist.
- sizeof(wchar_t) = 4 with GCC (2 with MS VC++)
- "FIXME" in source code indicates that you should add codes to better handle
all cases.
- "FIXED" in source code indicates that the original code has been changed to
work in Unix environment.
see also TODO file.
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