How to Tar a File in UNIX: A Comprehensive Guide for Beginners

Despite the common misconception, tarring a single file is not as uncommon as one might think. In an environment where support for multi-file operations is required, but only a single file is available, tarring can be a useful tool. This guide will explain how to create a tar file containing a single file in UNIX, along with a detailed overview of the tar command for those who want to delve deeper.

Why Would I Want to Tar a Single File?

While it may seem counter-intuitive, there are situations where tarring a single file is beneficial. For instance, certain applications or scripts require multiple files, but your workflow involves a single file. In such cases, creating a tar file can streamline the process. Let's consider an example where you have a single file named existing.txt and you want to create a tar file called newtarfile.tar. The following command will achieve this:

tar -cf newtarfile.tar existing.txt

This command initializes the tar process, appending the file existing.txt to the tar archive newtarfile.tar.

Exploring the tar Command Options

The tar command in UNIX is a versatile tool that offers a myriad of options for file management. Below is a detailed breakdown of the various options available (ignoring the first few for simplicity) along with a few examples:

Traditional Usage

tar {Acdrtux}[GnSkUWOmpsMBiajJzZhPlRvwo] [ARG...]

Here are a few common usage examples:

tar -cvf newtarfile.tar existing.txt - This command creates a new tar file named newtarfile.tar containing the file existing.txt. tar -xvf newtarfile.tar - This command extracts the contents of the tar file newtarfile.tar to the directory from which the command is executed.

UNIX-style Usage

tar -A [OPTIONS] ARCHIVE ARCHIVEtar -c [-f ARCHIVE] [OPTIONS] [FILE...]tar -d [-f ARCHIVE] [OPTIONS] [FILE...]tar -t [-f ARCHIVE] [OPTIONS] [MEMBER...]tar -r [-f ARCHIVE] [OPTIONS] [FILE...]tar -u [-f ARCHIVE] [OPTIONS] [FILE...]tar -x [-f ARCHIVE] [OPTIONS] [MEMBER...]

Again, here are a few examples:

tar -cvf newtarfile.tar existing.txt - This is the same as the previous example using traditional syntax. tar -xvf newtarfile.tar - Also the same, but using UNIX-style syntax.

GNU-style Usage

tar --create [--file ARCHIVE] [OPTIONS] [FILE...]tar --test-label [--file ARCHIVE] [OPTIONS] [LABEL...]tar --extract [-f ARCHIVE] [OPTIONS] [MEMBER...]tar --test-label [--file ARCHIVE] [OPTIONS] [LABEL...]tar --update [-f ARCHIVE] [OPTIONS] [FILE...]

The GNU-style commands offer similar functionality, with some minor differences. Here are a couple of examples:

tar --create --filenewtarfile.tar existing.txt - This creates a new tar file named newtarfile.tar containing the file existing.txt. tar --extract --filenewtarfile.tar - This extracts the contents of newtarfile.tar to the current directory.

These various options make the tar command a powerful tool for file management in UNIX, allowing for complex file archiving and management tasks.