NAME
7z – A file archiver with highest compression ratio
SYNOPSIS
7z [adeltux] [-] [SWITCH] …
DESCRIPTION
7-Zip is a file archiver with the highest compression ratio. The program supports 7z (that implements LZMA compression algorithm), LZMA2, XZ, ZIP, Zip64, CAB, RAR (if the non-free p7zip-rar package is installed), ARJ, GZIP, BZIP2, TAR, CPIO, RPM, ISO, most filesystem images and DEB formats. Compression ratio in the new 7z format is 30-50% better than ratio in ZIP format.
7z uses plugins to handle archives.
FUNCTION LETTERS
a Add
d Delete
e Extract
l List
t Test
u Update
x eXtract with full paths
SWITCHES
-ai[r[-|0]]{@listfile|!wildcard}
Include archives
-ax[r[-|0]]{@listfile|!wildcard}
eXclude archives
-bd
Disable percentage indicator
-i[r[-|0]]{@listfile|!wildcard}
Include filenames
-l
don’t store symlinks; store the files/directories they point to (CAUTION : the scanning stage can never end because of recursive symlinks like ‘ln -s .. ldir’)
-m{Parameters}
Set Compression Method (see /usr/share/doc/p7zip-full/DOCS/MANUAL/switches/method.htm for a list of methods)
-mhe=on|off
7z format only : enables or disables archive header encryption (Default : off)
-o{Directory}
Set Output directory
-p{Password}
Set Password
-r[-|0]
Recurse subdirectories (CAUTION: this flag does not do what you think, avoid using it)
-sfx[{name}]
Create SFX archive
-si
Read data from StdIn (eg: tar cf – directory | 7z a -si directory.tar.7z)
-so
Write data to StdOut (eg: % echo foo | 7z a dummy -tgzip -si -so > /dev/null)
-slt
Sets technical mode for l (list) command
-t{Type}
Type of archive (7z, zip, gzip, bzip2 or tar. 7z format is default)
-v{Size}[b|k|m|g]
Create volumes
-u[-][p#][q#][r#][x#][y#][z#][!newArchiveName]
Update options
-w[path]
Set Working directory
-x[r[-|0]]]{@listfile|!wildcard}
Exclude filenames
-y
Assume Yes on all queries
DIAGNOSTICS
7-Zip returns the following exit codes:
0 Normal (no errors or warnings detected)
1 Warning (Non fatal error(s)). For example, some files cannot be read during compressing. So they were not compressed
2 Fatal error
7 Bad command line parameters
8 Not enough memory for operation
255 User stopped the process with control-C (or similar)
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
7z 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
7z a -sfx archive.exe dir1
add all files from directory “dir1” to SFX archive archive.exe (Remark : SFX archive MUST end with “.exe”)
EXAMPLE 3
7z a -mhe=on -pmy_password archive.7z a_directory
add all files from directory “a_directory” to the archive “archive.7z” (with data and header archive encryption on)
