Master Advanced tar Techniques: Compression, Incremental Backups, and Encryption

Compression and Decompression

The most basic tar usage packs files into an archive and extracts them.

tar -cvf archive.tar file1 file2 ...

tar -xvf archive.tar

Add Files to an Existing Archive

Use the -r option to append new files without recreating the archive.

tar -rvf archive.tar newfile

Compress the Archive

Combine tar with gzip ( .gz) or bzip2 ( .bz2) to produce compressed archives.

tar -cvzf archive.tar.gz directory

tar -cvjf archive.tar.bz2 directory

Extract Only Specific Files

Use --wildcards with a pattern to extract matching files.

tar -xvf archive.tar --wildcards '*.txt'

Create Incremental Backups

The --listed-incremental option records changes since the last backup, allowing incremental archives.

tar --create --file=backup.tar --listed-incremental=snapshot.snar /directory/to/backup

Extract Specific Files from an Archive

Combine --extract with --wildcards to pull only selected files.

tar -xvf archive.tar --wildcards '*.txt'

Archive and Compress to a Specific Directory

Use -C to change to a target directory before creating the archive.

tar -cvzf /path/to/destination/archive.tar.gz -C /path/to/source directory

Archive While Excluding Certain Files or Directories

The --exclude option omits paths such as a .git folder.

tar -cvf backup.tar --exclude='.git' /home/user

Encrypt an Archive

Pipe the tar output to openssl for AES‑256 encryption.

tar -cvf - directory | openssl aes-256-cbc -salt -out archive.tar.enc

Limit Archive File Size

The --tape-length option caps the archive size; excess data is written to a new file.

tar -cvf backup.tar --tape-length=1G directory

Summary

The article covers several advanced tar usages: adding files to existing archives, compressing with gzip or bzip2, extracting selective files, creating incremental backups, excluding paths, encrypting archives, limiting archive size, and directing output to specific directories. These techniques help Linux users manage files more flexibly and efficiently.