Cross Platform Compression

Last updated: 2020-04-30

.zip Format

To compress a folder:

zip -r archive_name.zip folder\_to\_compress

# To declare a compression value, add a numeric parameter
# 9 is the highest
zip -r9 archive_name.zip folder\_to\_compress

# On macOS, ignore invisible files (.DS_Store)
zip -r9 -X archive_name.zip folder\_to\_compress

To compress multiple folders into individual, unique zips:

for i in */; do zip -r "${i%/}.zip" "$i"; done

To extract the contents of a zip file:

unzip archive_name.zip

List the details about a zip archive:

zipinfo archive_name.zip

Encryption

Create a password protected and encrypted zip:

zip -ejr [name] [path\_to\_folder]

Once you execute this command, macOS will ask for the desired password (twice, for confirmation), and then create a zip archive of your folder with your chosen name at the root level of your home folder. (If you want to specify a different location, you need to provide the full path instead of just the name.)

• name: archive file name (no .zip extension). [name] is the name you want to give to the resulting archive file (without the ".zip" extension, which the zip command will add automatically).
• path_to_folder: target directory to be zipped. [path\_to\_folder] is the complete name of the folder with its full path. Instead of typing it, you can just type zip -ejr[name] followed by a space and then drag-and-drop the target folder onto the command line. Terminal will automatically insert the full path with escape characters if required.

Flags

• e: encryption
• j: junk the path
• r: recursive
• 9: max compression

The e option stands for encryption the j for junk the path (otherwise the zip command will archive the complete folder hierarchy leading to your target folder, which you probably don’t want), and r stands for recursive which will force the zip command to include the entire contents of the folder in the archive. (Otherwise it will only archive the folder itself without its contents, which is not exactly useful.)

.tar Format

To compress a folder:

tar -cvzf archive_name.tar.gz folder\_to\_compress

# Compress only JPG files (example)
tar -cvzf archive_name.tar.gz /path/to/images/*.jpg

To extract the contents of a tar file:

cd location_of_tar_file

# extract to current directory
tar -xvf yourfile.tar

# extract to different directory
tar -C /myfolder -xvf yourfile.tar

tar.bz2 Format

# to compress
tar -jcvf archive_name.tar.bz2 folder_to_compress

# to extract
tar -jxvf archive_name.tar.bz2