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Why doesn’t “less” automatically decompress gzipped files on Ubuntu?

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In the world of Linux, the less command is a powerful tool for viewing the contents of files without actually opening them. However, if you’ve migrated from a Fedora/Redhat/CentOS environment to Ubuntu, you may have noticed a peculiar difference: the less command doesn’t automatically decompress gzipped files on Ubuntu. This article aims to explain why this is the case and provide workarounds for this behavior.

Quick Answer

The "less" command in Ubuntu does not automatically decompress gzipped files like it does in Fedora/Redhat/CentOS. This is due to the difference in the default settings and environment variables between the two distributions. However, there are workarounds available such as using the "zless" command or using "zcat" to decompress the file before piping it to "less".

Understanding the “less” Command

Before we delve into the specifics, let’s take a moment to understand what the less command does. less is a command-line utility that allows you to view the contents of a file one screen at a time. You can move forward and backward in the file, search for text, and do other operations. It’s similar to the more command but has more features.

The Difference Between Fedora/Redhat/CentOS and Ubuntu

On Fedora/Redhat/CentOS, the less command has built-in support for automatically detecting and decompressing gzipped files. This means that you can simply use less my_stuff.csv.gz and it will work seamlessly, decompressing the gzipped file and displaying its contents.

However, on Ubuntu, this feature is not present in the default less command. Instead, you can use the zless command, which is a script installed by default in Ubuntu and most other distributions. You can use zless my_stuff.csv.gz to achieve the same result.

The key difference here lies in the environment variable LESSOPEN. On Fedora, this variable is set to force the argument through lesspipe, which allows for automatic decompression. This is not the case in Ubuntu.

Workaround: Using the “zless” Command

As mentioned earlier, Ubuntu comes with a built-in command called zless that is specifically designed to read gzipped files. The zless command is essentially a script that combines the gzip -cd and less commands to decompress and read gzipped files.

Here’s how you can use it:

zless my_stuff.csv.gz

This command will decompress the my_stuff.csv.gz file and display its contents.

Workaround: Using the “zcat” Command

If you prefer to use the less command directly on gzipped files in Ubuntu, you can use the zcat command to decompress the file and pipe it to less. The zcat command is equivalent to gzip -cd, it decompresses the gzipped file and sends the output to the standard output.

Here’s how you can use it:

zcat my_stuff.csv.gz | less

This command will decompress the my_stuff.csv.gz file and pipe the output to less, allowing you to view the contents of the file.

Conclusion

In conclusion, while the less command in Ubuntu doesn’t automatically decompress gzipped files like it does in Fedora/Redhat/CentOS, there are workarounds available. You can use the zless command or use zcat to decompress the file before piping it to less. Understanding these differences and workarounds can help you navigate the Linux command line more effectively, regardless of your distribution.

Why doesn’t the `less` command automatically decompress gzipped files on Ubuntu?

The less command in Ubuntu does not have built-in support for automatically detecting and decompressing gzipped files like it does in Fedora/Redhat/CentOS. However, you can use the zless command or the zcat command as workarounds to achieve the same result.

What is the difference between the `less` and `more` commands?

The less and more commands are both used for viewing the contents of files without opening them fully. However, less provides more features and allows you to move forward and backward in the file, search for text, and perform other operations, while more only allows you to move forward in the file.

How do I use the `zless` command to view the contents of a gzipped file?

To use the zless command, simply type zless followed by the name of the gzipped file you want to view. For example: zless my_stuff.csv.gz. This command will automatically decompress the gzipped file and display its contents.

Can I use the `less` command directly on gzipped files in Ubuntu?

Yes, you can use the zcat command to decompress the gzipped file and pipe it to less. Simply type zcat followed by the name of the gzipped file, and then use the pipe (|) symbol to send the output to less. For example: zcat my_stuff.csv.gz | less. This command will decompress the gzipped file and allow you to view its contents using less.

How can I navigate through the file when using the `less` command?

When using the less command, you can navigate through the file by using the arrow keys on your keyboard. Press the down arrow key to scroll down one line at a time, or the up arrow key to scroll up. You can also use the Page Up and Page Down keys to scroll through the file faster. Additionally, you can search for specific text within the file by typing / followed by the search term and pressing Enter.

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