7-Zip is a file archiver with the highest compression ratio. The program supports 7z (that implements LZMA compression algorithm), ZIP, CAB, ARJ, GZIP, BZIP2, TAR, CPIO, RPM and DEB formats. Compression ratio in the new 7z format is 30-50% better than ratio in ZIP format.
7za is a stand-alone executable. 7za handles less archive formats than 7z, but does not need any others.
FUNCTION LETTERS
a
Add
d
Delete
e
Extract
l
List
t
Test
u
Update
x
eXtract with full paths
SWITCHES
-ai
Include archives
-ax
eXclude archives
-bd
Disable percentage indicator
-i
Include filenames
-m
Set Compression Method
-o
Set Output directory
-p
Set Password
-sfx
Create SFX archive
-si
Read data from StdIn
-so
Write data to StdOut
-t
Type of archive
-v
Create volumes
-u
Update options
-w
Set Working directory
-x
Exclude filenames
-y
Assume Yes on all queries
Backup and limitations
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")
EXAMPLE 1
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
EXAMPLE 2
7za a -sfx archive.exe dir1
add all files from directory "dir1" to SFX archive archive.exe (Remark : SFX archive MUST end with ".exe")
MORE EXAMPLES
You will find more examples in /usr/share/doc/p7zip/DOCS/MANUAL .