7z

---
tags: [ compression ]
---
7z [Args] [archive.7z] [files / folders to archive]
A file archiver with highest compression ratio

Args:
a       add
d       delete
e       extract
l       list
t       test
u       update
x       extract with full paths

    DO NOT USE the 7-zip format for backup purpose on Linux/Unix.
    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 | 7z a -si directory.tar.7z
      - to restore your backup : 7z 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 1: Quick and Easy - Add all files in dir1 to archive.7z with Default Settings.
7z a archive.7z  dir1

Example 2: Add all files in dir1 to archive.7z with Max Compression
7z a -t7z -m0=lzma -mx=9 -mfb=64 -md=32m -ms=on archive.7z dir1

    -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 Mb
    -ms=on      solid archive = on

Example 3: Add (store) all files in dir1 to archive.7z with No Compression
7z a -m0=copy archive.7z dir1

7z exit codes:

    0       normal (no errors or warnings)
    1       warning (non-fatal errors)
    2       fatal error
    7       bad cli arguments
    8       not enough memory for operation
    255     process was interrupted