Zip Command in Linux

Introduction to Zip Command in Linux

ZIP is a file packaging utility compression technique in Unix. Each file is stored in a single file with the extension.zip.This zip command in Linux is usually supported by almost all operating systems like MSDOS, OS/2, Window NT, Minix, and Macintosh, etc. Compress and tar is used with this Zip command and compatible with PKZIP(Phil Katz’s ZIP for MSDOS systems).

Syntax:

zip [with some options]  zipFIle  fileDir/fileList

The zip file is a new or existing zip archive and fileDir/fileList is the path occasionally including wildcards. when the same name of zip archive is found then it will update it.

Example: If folder/file_1 and folder/file_2 is contained in folder.zip and the directory folder contains the files folder/file_1 and folder/file_3. So, if before a zip command will execute, folder.zip has:

folder/file_1
folder/file_2

Also, when the directory folder has:

file_1
file_3

and  folder.zip will have now:

folder/file_1
folder/file_2
folder/file_3

Where folder/file_1 is replaced whereas folder/file_3 is new.So, folder.zip now contains folder/file_1, folder/file_2, and folder/file_3, along folder/file_2 from before that are unchanged.

Syntax to Extract Zip Files in Linux

Unzip command extracts list files from the ZIP archive on Unix systems. When no option is used to extract it into the present working directory (and sub-directories which are inside it) every file from the specified ZIP archive.

Syntax:

$unzip fold.zip

Zip Command Options in Linux

Now let us focus on the Zip command Options below:

1) -u Option

Updates the file in the zip archive. This also updates an existing entry in the zip archive, and only if it has been modified more now than the version already in the zip archive.

Command:

$zip –u file_name.zip file.txt

Suppose we have the files in the current directory are listed below:

file1.txt
file2.txt
file3.txt
file4.txt

Command:

$zip –u file_name.zip file5.txt

After updating file5.txt from file_name.zip file, the files will be restored with unzip command.

Command:

$unzip file_name.zip
$ls command

Output:

file1.txt
file2.txt
file3.txt
file4.txt
file5.txt

The file5.txt file is updated to the zip file.

2) -d Option

It deletes the file from the zip archive. This option deletes the created zip file. Suppose we have the files in the current directory are listed below:

file1.txt,file2.txt,file3.txt,file4.txt,file5.txt

Syntax:

$zip –d file_name.zip file.txt

Command:

$zip –d file_name.zip file5.txt

After removing file5.txt from file_name.zip file, the files will be restored using unzip command

Command:

$unzip file_name.zip
$ls command

Output:

file1.txt
file2.txt
file3.txt
file4.txt

The file5.txt file is removed from zip file

3) -m Option

Will delete original/main files after zipping. It will move the files by making zip and delete the original files/folder.

If a directory becomes empty after deleting files, the respective directory is also deleted. No deletions are completed until the zip has created archive without any error. So this is useful in maintaining disk space, but ultimately unsafe while removing all input files.

Syntax:

$zip –m file_name.zip file.txt

Suppose we have the files in the current directory are listed below:

file_1.txt,file_2.txt,file_3.txt,file_4.txt

Command :

$zip –m file_name.zip *.txt

After the execution of this command on the terminal here is the result:

Command:

$ls command

Output:

file_name.zip
//No other files as .txt(extension) are found

4) -x Option

It will exclude files when we are going to create the zip. Let say you are going to zip all the files in the present directory and want to exclude few files which are not needed. So you can exclude these files which are not needed using the -x option.

Syntax:

$zip –x file_name.zip file_to_be_excluded

Suppose we have the files in the current directory are listed below:

file_1.txt,file_2.txt,file_3.txt,file_4.txt

Command:

$zip –x file_name.zip file_3.txt

This command while executing will compress every file except file_3.txt

Command:

$ls command

Output:

file_name.zip  // compressed file
file_3.txt   //this file will be excluded while doing compression

5) -r Option

It will recursively zip the files inside it and then folders inside it.

Syntax:

$zip –r file_name.zip directory_name

Suppose we have the files in the current directory (doc) are listed below:

a.pdf
b.pdf
c.pdf

Command:

$zip –r filedir.zip doc

Output:

adding: doc/                  //Compressing the directory
adding: doc/a.pdf    // Compressing first file
adding: doc/b.pdf // Compressing second file
adding: doc/c.pdf  //Compressing the third file

6) -v Option

Using the Verbose mode option we will print diagnostic version information. This option will display the progress indicator during compression and request verbose information about the zip structure.

Syntax:

$zip –v file_name.zip file.txt

Suppose we have the files in the current directory are listed below:

file_1.txt,file_2.txt,file_3.txt,file_4.txt

Command:

$zip -v file1.zip *.txt

Output:

adding: file_1.txt     (in=0) (out=0) (stored 0%)
adding: file_2.txt    (in=0) (out=0) (stored 0%)
adding: file_3.txt    (in=0) (out=0) (stored 0%)
adding: file_4.txt    (in=0) (out=0) (stored 0%)

total bytes=0, compressed=0 -> 0% savings

Uses of Zip Command in Linux

The uses of Zip Command in Linux are as follows.

• ZIP is a perfect technique when there is less bandwidth or internet speed and you want to transfer a bunch of files. Then now using this command you can zip and transfer the files in a very efficient manner.
• The zip program puts one or more compressed files into a single zip archive, along with information like name, path, date, time of last modification, protection, and check information to verify file integrity. An entire directory structure can be compressed into a zip archive by a single command.
• 2:1 to 3:1 as the compression ratio is prevalent for text files either uses a deflation method or store files without compression. This will choose automatically the best for each file to be compressed.
• It comes very handy for archiving files; packaging a set of files for distribution and for saving disk space for a short time by compressing unused files or directories.

Conclusion

Now we have understood the depression (unzip) and compression (zip) concept and we have seen how to manipulate compressed files using different options. ZIP is a perfect technique when there is less bandwidth or internet speed and you want to transfer a bunch of files. Then now using this command you can zip and transfer the files in a very efficient manner.