Using the tar Command for File Compression

tar (tape archive) joins many files and folders into one archive file. With an option it also compresses the archive (gzip, bzip2 or xz).

Syntax

tar [options] [archive_name] [files_or_directories]

-c creates a new archive.
-x extracts files from an archive.
-t lists the contents of an archive.
-f gives the name of the archive file. Always put it last in a group of options, before the file name.
-v shows the files while it works (verbose).
-z compresses or decompresses with gzip (.tar.gz).
-j uses bzip2 (.tar.bz2).
-J uses xz (.tar.xz).
-r appends files to an existing, uncompressed archive.
-u adds files that are newer than those in the archive.
-A joins several archives.
-W verifies the archive after writing it.
-C changes to a folder before it extracts or creates.

tar -cvf archive.tar folder/

gzip:

tar -czvf archive.tar.gz folder/

bzip2 (smaller, slower):

tar -cjvf archive.tar.bz2 folder/

xz (smallest, slowest):

tar -cJvf archive.tar.xz folder/

tar -tvf archive.tar.gz

gzip archive in the current folder:

tar -xzvf archive.tar.gz

Into a chosen folder:

tar -xzvf archive.tar.gz -C /path/to/folder

bzip2 archive:

tar -xjvf archive.tar.bz2

Any type (modern tar picks the compression by itself):

tar -xf archive.tar.xz

Extract one file:

tar -xzvf archive.tar.gz folder/file.txt

tar -rvf archive.tar newfile.txt

This works for uncompressed archives only.

tar -czvf backup.tar.gz --exclude='*.log' --exclude='node_modules' project/

tar -tzf archive.tar.gz > /dev/null && echo OK

Use absolute paths carefully. By default tar removes the leading / from paths.
Add a date to backup names: backup-$(date +%F).tar.gz.
Preserve permissions with -p when you extract as root.