We all know about GNU core utilities that comes pre-installed with all Linux and Unix-like operating systems. These are the basic file, shell and text manipulation utilities of the GNU operating system. The GNU core utilities contains the commands, such as cat, ls, rm, mkdir, rmdir, touch, tail, wc and many more, for performing the day-to-day operations. Among these utilities, there are also some other useful collection of Unix utilities which are not included by default in the Unix-like operating systems. Meet moreutilis, a growing collection of more useful Unix utilities. The moreutils can be installed on GNU/Linux, and various Unix flavours such as FreeBSD, openBSD and Mac OS.
List Of Available Utilities In Moreutils
As of writing this guide, Moreutils provides the following utilities:
- chronic - Runs a command quietly unless it fails.
- combine - Combine the lines in two files using boolean operations.
- errno - Look up errno names and descriptions.
- ifdata - Get network interface info without parsing ifconfig output.
- ifne - Run a program if the standard input is not empty.
- isutf8 - Check if a file or standard input is utf-8.
- lckdo - Execute a program with a lock held.
- mispipe - Pipe two commands, returning the exit status of the first.
- parallel - Run multiple jobs at once.
- pee - tee standard input to pipes.
- sponge - Soak up standard input and write to a file.
- ts - timestamp standard input.
- vidir - Edit a directory in your text editor.
- vipe - Insert a text editor into a pipe.
- zrun - Automatically uncompress arguments to command.
Install moreutils on Linux
The moreutils is packaged for many Linux distributions, so you can install it using the distribution's package manager.
On Arch Linux and derivatives such as Antergos, Manjaro Linux, run the following command to install moreutils.
$ sudo pacman -S moreutils
$ sudo dnf install moreutils
On RHEL, CentOS, Scientific Linux:
$ sudo yum install epel-release
$ sudo yum install moreutils
On Debian, Ubuntu, Linux Mint:
$ sudo apt-get install moreutils
Moreutils Brings More Useful Unix Utilities
Let us see the usage details of some moreutils tools.
The "Combine" utility
As the name implies, the Combine utility combines the sets of lines from two files using boolean operations such as "and", "not", "or", "xor".
- and - Outputs lines that are in file1 if they are also present in file2.
- not - Outputs lines that are in file1 but not in file2.
- or - Outputs lines that are in file1 or file2.
- xor - Outputs lines that are in either file1 or file2, but not in both files.
Let me show you an example, so you can understand what exactly this utility will do . I have two files namely file1 and file2. Here is the contents of the those two files.
$ cat file1 is was were where there
$ cat file2 is were there
Now, let me combine them using "and" boolean operation.
$ combine file1 and file2 is were there
As you see in the above example, the "and" Boolean operator outputs lines that are in file1 if they are also present in file2. To put this more clearly, it displays the common lines(Ex. is, were, there) which are present in both files.
Let us now use "not" operator and see the result.
$ combine file1 not file2 was where
As you see in the above output, the "not" operator displays the lines that are only in file1, but not in file2.
The "ifdata" utility
The "ifdata" utility can be used to check for the existence of a network interface, to get information about the network interface, such as its IP address. Unlike the built-in commands such as "ifconfig" or "ip", ifdata has simple to parse output that is designed to be easily used by a shell script.
To display IP address details of a network interface, say wlp9s0, run:
$ ifdata -p wlp9s0 192.168.43.192 255.255.255.0 192.168.43.255 1500
To display the netmask only, run:
$ ifdata -pn wlp9s0 255.255.255.0
To check hardware address of a NIC:
$ ifdata -ph wlp9s0 A0:15:46:90:12:3E
To check if a NIC exists or not, use "-pe" flag.
$ ifdata -pe wlp9s0 yes
The "Pee" command
It is somewhat similar to "tee" command.
Let us see an example of "tee" command usage.
$ echo "Welcome to OSTechNIx" | tee file1 file2 Welcome to OSTechNIx
The above command will create two files namely file1 and file2. Then, append the line "Welcome to OSTechNix" on both files. And finally prints the message "Welcome to OSTechNix" in your Terminal.
The "Pee" command performs a similar function, but slightly differs from "tee" command. Look at the following command:
$ echo "Welcome to OSTechNIx" | pee cat cat Welcome to OSTechNIx Welcome to OSTechNIx
As you see in the above output, the two instances of "cat" command receives the output from "echo" command and displays them twice in the Terminal.
The "Sponge" utility
This is yet another useful utility from moreutils package. Sponge reads standard input and writes it out to the specified file. Unlike a shell redirect, sponge soaks up all its input before writing the output file.
Have a look at the contents of following text file.
$ cat file1 I You Me We Us
As you see, the file contains some random lines, particularly "not" in alphabetical order. You want to sort the contents in alphabetical order. What would you do?
$ sort file1 > file1_sorted
Correct, isn't it? Of course! As you see in the above command, I have sorted the contents of the file1 in alphabetical order and saved them in a new file called "file1_sorted". But, You can do the same without creating a new (i.e file1_sorted) using "sponge" command as shown below.
$ sort file1 | sponge file1
Now, check if the contents are sorted in alphabetical order.
$ cat file1 I Me Us We You
See? we don't need to create a new file. It's very useful in scripting. And the good thing is sponge preserves the permissions of the output file if it already exists.
The "ts" utility
The "ts" utility prints the timestamp to the beginning of each line in any Linux command's output.
Look at the following command's output:
$ ping -c 2 localhost PING localhost(localhost.localdomain (::1)) 56 data bytes 64 bytes from localhost.localdomain (::1): icmp_seq=1 ttl=64 time=0.055 ms 64 bytes from localhost.localdomain (::1): icmp_seq=2 ttl=64 time=0.079 ms --- localhost ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1018ms rtt min/avg/max/mdev = 0.055/0.067/0.079/0.012 ms
Now, run the same command with "ts" utlity as shown below.
$ ping -c 2 localhost | ts Aug 21 13:32:28 PING localhost(localhost (::1)) 56 data bytes Aug 21 13:32:28 64 bytes from localhost (::1): icmp_seq=1 ttl=64 time=0.063 ms Aug 21 13:32:28 64 bytes from localhost (::1): icmp_seq=2 ttl=64 time=0.113 ms Aug 21 13:32:28 Aug 21 13:32:28 --- localhost ping statistics --- Aug 21 13:32:28 2 packets transmitted, 2 received, 0% packet loss, time 4ms Aug 21 13:32:28 rtt min/avg/max/mdev = 0.063/0.088/0.113/0.025 ms
As you see in the above output, ts adds a timestamp at the beginning of each line. Here is another example.
$ ls -l | ts Aug 21 13:34:25 total 120 Aug 21 13:34:25 drwxr-xr-x 2 sk users 12288 Aug 20 20:05 Desktop Aug 21 13:34:25 drwxr-xr-x 2 sk users 4096 Aug 10 18:44 Documents Aug 21 13:34:25 drwxr-xr-x 24 sk users 12288 Aug 21 13:06 Downloads [...]
The "Vidir" utility
The "Vidir" utility allows you to edit the contents of a specified directory in vi editor (Or, whatever you have in $EDITOR). If no directory is specified, it will edit your current working directory.
The following command edits the contents of the directory called "Desktop".
$ vidir Desktop/
The above command will open the specified directory in your vi editor. Each item in the editing directory will contain a number. You can now edit the files as the way you do in vi editor. Say for example, delete lines to remove files from the directory, or edit filenames to rename files.
You can edit the sub directories as well. The following command edits the current working directory along with its sub-directories.
$ find | vidir -
Please note the "-" at the end of the command. If "-" is specified as the directory to edit, it reads a list of filenames from stdin and displays those for editing.
If you want to edit only the files in the current working directory, you can use the following command:
$ find -type f | vidir -
Want to edit a specific file types, say .PNG files? then you would use:
$ vidir *.png
This command edits only the .png files in the current directory.
The "Vipe" utility
The "vipe" command allows you to run your default editor in the middle of a Unix pipeline and edit the data that is being piped between programs.
The following command opens the vi editor (default editor, of course) and allows you to edit the input of the "echo" command (i.e Welcome To OSTechNix) and displays the final result.
$ echo "Welcome to OSTechNIx" | vipe Hello World
As you see in the above output, I passed the input "Welcome to OSTechNix" to vi editor and edited them as "Hello World" and displayed the final output.
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And, that's all for now. I have covered only a few utilities. The "moreutils" has more useful utilities. I already have mentioned the currently included utilities in moreutils package in the introductory section. You can read the man pages for greater detail on the above commands. Say for example, to know more about "vidir" command, run:
$ man vidir
Hope this helps.
Seriously, do I need this???
Thank you so much for the great topic,