Tanguy Ortolo

Streamable archive formats

Archive formats such as tar(5) and cpio(5) have the advantage of being streamable, so you can use them for transferring data with pipes and remote shells, without having to store the archive in the middle of the process, for instance:

$ cd public_html/blog
$ rgrep -lF "archive" data/articles \
      | pax -w \
      | ssh newserver "mkdir public_html/blog ;
                       cd public_html/blog ;
                       pax -r"

Read more Using bsdtar to change an archive format

Sometimes, you have to use ZIP archives, or worse, RAR archives (curse them!), with one significant annoyance: zip, unzip, rar and unrar use a rather uncommon command line convention, compared to the usual tar, cpio and pax.

Read more One archiver to rule them all: bsdtar

tar and cpio

tar(5) and cpio(5) are two competing archive formats, that provide almost identical features. Both are streamed formats, originally designed to be used on tapes. Their major practical difference is the style of their standard command line utilities:

• cpio(1) takes the list of files to archive on its standard input, allowing a very high control but requiring to use another utility such as find(1) to archive an entire tree;
• tar(1) usually takes the list of file to archive on its command line, and browses directories recursively be default.

Read more cpio > tar