Useful Utils
Utility is when you have one telephone, luxury is when you have two, opulence is when you have three - and paradise is when you have none - Doug Larson
Photo by Lachlan Donald on Unsplash
This page is a collection of tools that I have found useful over the years. I anticipate that it will grow as I remember tools or new tools come up.
Trash-cli
This Linux utility has prevented me from using the dreaded ‘rm -rf’ command in my root directory. Trash-cli is an alternative for the “remove” or rm command.
On Ubuntu or Red Hat the package name is the same: trash-cli. On Red Hat simply enter:
sudo dnf install trash-cli
Running the “trash” command after installing the package sends the files to the "trash" -- rather than the operating system completely removing them. — see Trash (computing) - Wikipedia. Trash works for files and directories, making it a drop-in replacement for rm.
Example usage:
Let’s see this in action. Open a terminal in Linux and enter:
touch test.txt
trash test.txt
Confirm the file is gone using ls. Fear not though, it is only in the trash! Enter trash-restore at the terminal and you should see it somewhere in the list. My terminal yields:
[mday@localhost ~]$ trash-restore
0 2023-04-14 15:03:10 /home/mday/…/devel-rpms.tar.gz
1 2023-04-18 08:50:32 /home/mday/test.txt
What file to restore [0..1]:
This says there are 2 entries in my trash and I want the second one so I enter ‘1’
A simple ls command should reveal that the file has been restored!
df -h
To visualize disk usage on Linux in a human-readable format enter:
df -h
There are many other options for the df command as well. When I enter it I in my Red Hat Enterprise Linux Virtual Machine I get:
[mday@localhost ~]$ df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 3.9G 0 3.9G 0% /dev
tmpfs 3.9G 0 3.9G 0% /dev/shm
tmpfs 3.9G 9.3M 3.9G 1% /run
tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
/dev/mapper/rhel-root 14G 9.6G 3.8G 72% /
/dev/sda1 1014M 356M 659M 36% /boot
C_DRIVE 944G 335G 610G 36% /media/sf_C_DRIVE
tmpfs 796M 24K 796M 1% /run/user/1000
ps -aux
My favorite way to see what processes are running on Linux is:
ps -aux
There are many other options for the ps command as well.
Example usage:
To list all of the processes currently running enter the command:
ps -aux
This results in something like the following:
mday 2422 0.3 0.5 695896 42468 tty2 Sl+ 08:14 0:00 /usr/libexec/platform-python
mday 2430 1.1 1.0 1267372 81508 tty2 Sl+ 08:14 0:00 /usr/bin/gnome-software --ga
mday 2432 0.2 0.3 748656 31564 ? Ssl 08:14 0:00 /usr/libexec/tracker-store
mday 2435 0.0 0.0 214924 7660 ? Sl 08:14 0:00 /usr/libexec/dconf-service
mday 2437 0.2 0.6 1310288 49928 ? Ssl 08:14 0:00 /usr/libexec/evolution-addre
mday 2442 0.3 0.7 1375692 64580 tty2 Sl+ 08:14 0:00 /usr/libexec/evolution/evolu
mday 2458 0.0 0.1 301372 8888 tty2 Sl+ 08:14 0:00 /usr/libexec/gsd-disk-utilit
mday 2472 0.2 0.3 906572 26116 tty2 SNl+ 08:14 0:00 /usr/libexec/tracker-miner-a
mday 2476 0.2 0.3 850544 28016 tty2 SNl+ 08:14 0:00 /usr/libexec/tracker-miner-f
mday 2496 0.0 0.0 253248 308 ? S 08:14 0:00 /usr/bin/VBoxClient --clipbo
mday 2497 0.0 0.0 453476 2124 ? Sl 08:14 0:00 /usr/bin/VBoxClient --clipbo
mday 2518 0.0 0.0 253248 308 ? S 08:14 0:00 /usr/bin/VBoxClient --seamle
mday 2519 0.0 0.0 451536 2752 ? Sl 08:14 0:00 /usr/bin/VBoxClient --seamle
mday 2530 0.2 0.6 1588300 51144 ? Sl 08:14 0:00 /usr/libexec/evolution-addre
mday 2536 0.0 0.0 253248 308 ? S 08:14 0:00 /usr/bin/VBoxClient --dragan
mday 2538 0.3 0.0 517588 2804 ? Sl 08:14 0:00 /usr/bin/VBoxClient --dragan
mday 2539 0.0 0.0 253248 308 ? S 08:14 0:00 /usr/bin/VBoxClient --vmsvga
mday 2540 0.0 0.0 385352 2440 ? Sl 08:14 0:00 /usr/bin/VBoxClient --vmsvga
root 2686 0.2 0.3 846952 25828 ? Ssl 08:14 0:00 /usr/libexec/fwupd/fwupd
mday 2719 1.3 0.4 730096 39452 ? Ssl 08:15 0:00 /usr/libexec/gnome-terminal-
mday 2724 0.0 0.0 226364 5468 pts/0 Ss 08:15 0:00 bash
root 2841 0.0 0.0 217084 912 ? S 08:15 0:00 sleep 60
mday 2877 0.0 0.0 271488 4184 pts/0 R+ 08:16 0:00 ps -aux
Let’s see how to use ps in conjunction with kill!
kill & kill -9
Speaking of processes: want to kill a process in Linux? Just use:
kill <process-id>
In the example above, to kill the bash process running under my user id enter:
kill 2724
at the terminal.
If you want to try this at home it is nearly certain you want a different number than 2724! See process identifier.
But that didn’t work! The reason is because I am currently logged in to the bash shell session in question and the system is trying to prevent me from doing something it thinks is dumb. The answer: kill -9. Let’s try it now!
kill -9 2724
Again, you will need to enter a different process identifier if you want to try this on your machine.
That worked! My bash session abruptly terminated! To understand what happened see this stackoverflow thread. In a nutshell what happens when you enter kill is that the operating system asks nicely to end the process. The -9 does away with the asking nicely part.
More utilities to come (probably)…
