Categoría: gnu

This is a simple command. It give us the system information. It has a few options, as: uname -a -> shows all info uname – v -> shows kernel version uname – o -> shows operating system version There are many options, so as always, check the man pages for more info.

This simple command is able to do a few things. If you read the man description it will tell you this: touch – change file timestamps so basically this tool changes the timestamp of a file, but it can also do: A FILE argument that does not exist is created empty, unless -c or -h […]

Have you ever wondered what is taking so much space in your hard drives? You have thousands of files but you dont know what is what or where are the biggest files. Well, sometimes you need a way to know what is inside your hard drive. You can achieve this with a beautiful and useful […]

There is a not very well known bash command that allows you to repeat the last input you typed in the shell. Behold the “!!” command. This simply allows us to retype the last input. For instance: If I type: (to list files in the local directory): ls -lh and after that I type: !! […]

Have you ever wanted to delete “permanently” a file from your file system?. Well, you can do it with this command: shred . First, a litle about how a file system works. Simply put, the system keeps a table with references to each file. When you delete a file what really happens is that the […]

This can be seen as an improvement of the classical command df, that allows us to show the file system disk space usage. If you type df -h (the h option is for human readable) it will show you something like this: tmpfs 1,6G 2,8M 1,6G 1% /run/dev/nvme0n1p2 468G 222G 223G 50% /tmpfs 7,8G 0 […]

Have you ever wondered how to get the path of the working directory?. To do that you can use the command: PWD . This simple order gives you precisely that, the working directory, for instance: pwd > returns /home/user/dir As always use the man command to get more info about the inner details of this […]

This couple of commands are really helpful. It allows you to easily navigate through the system without having to repeat long paths. For example, imagine that you are in the directory /user/data/data2/home/ but want to change to other directory for a moment, say /etc ; you can do: pushd /etc -> this will move to […]

This is an interesting command. Have you ever wanted to be sure that just one instance of your app/script is running at the same time? Then, flock is your tool. The sintax is as follows: flock [options] file|directory command [arguments] Lets see an example: flock /home/user/lockfile htop This runs htop and uses a generated file […]

This is one of those extremely useful commands that not many people know. Basically runs a shell command and exits when the time runs out. The format is as follows: timeout [OPTION] DURATION COMMAND [ARG]… Lets see an example: timeout 10s top : This starts the top utility waits for 10 seconds and quit. Simple. […]