Radu Rădeanu's questions

Something similar to this Q&A, I know that cd will change current working directory in terminal to a new directory like this:

cd /path/to/new_directory

But I wonder how can I change current working directory only by typing for example:

/path/to/new_directory

followed by Enter, of course. Nothing more.

Many times I have run a command with all the letters in uppercase (maybe because CapsLock was on), and I pressed Enter before realising this.

How can I run the last command with all the letters transformed to lowercase?

I use the man command all the time when I want to get information about a specific command. But this doesn't help me too much when that specific command is a shell builtin. For example:

man cd

returns:

No manual entry for cd

My question is: it is possible to make man also work for all shell builtin commands (like cd, alias, history, etc.), and keywords (like if, while, [[, {, etc.)?

I want to have an option like Search on Google available in selected text's context menu in gnome-terminal. Something similar to the option which is available in selected text's context menu in google chrome / chromium / firefox browser:

So, something similar like in the above image, but in gnome-terminal. Is this possible?

I know that xdg-open will open from terminal a file in the user's preferred application like this:

xdg-open filename

But I wonder how can I open a file from the current directory in its default application only by typing:

filename

followed by Enter, of course. Nothing more.

What is the simplest way to create a file using a command-line? Usually I use:

touch filename

But is this the simplest/fastest way?

In Ubuntu, applications can be opened from a terminal. But sometimes it isn't clear what the appropriate command is to do this.

So, having an application open, how can I get the command used to launch it, without having to search anywhere (just by looking at it)?

Many times I need to extract different kinds of archived files using commad-line. But not all the time I remember the exact command for any type of file archive. So, I have to waste time and search again. How can I avoid this?

After I saw this answer, I realized that there are many guest accounts on my system:

grep guest /etc/passwd
guest-jzXeRx:x:117:127:Guest,,,:/tmp/guest-jzXeRx:/bin/false
guest-l5dAPU:x:118:128:Guest,,,:/tmp/guest-l5dAPU:/bin/false
guest-FdSAkw:x:119:129:Guest,,,:/tmp/guest-FdSAkw:/bin/false
guest-eBU0cU:x:121:131:Guest,,,:/tmp/guest-eBU0cU:/bin/false

Moreover, in this moment there is nobody logged as guest, but if somebody will login as guest, a new guest account is created - why, since there are already other guest accounts? After the new guest will log out, his account will be deleted. But why the other guest accounts remain? For what use/purpose?

It doesn't mind me at all this guest account, but I want to know if it is okay to delete them manually.

After I read List all human users I noticed that there is a user account named 'nobody' in my Ubuntu system.

Also I noticed that I can login in this account from terminal using the following command and my password:

sudo su nobody

It doesn't mind me at all, but I want to know what is the purpose of this user? Is it created by default on a fresh install of Ubuntu or is created by installing a particular package?

Using ttyrec I can record any console program (ttyrec invokes a shell and records the session until the shell exits). The record is saved by default in a ttyrecord file and can be played using ttyplay ttyrecord command.

Now, I want to convert this ttyrecord file in a .gif file. I found this phyton script (tty2gif.py), but, no matter how I do, I can not manage to make it to work...

Any other solutions will be appreciated!

I created a new profile for gnome-terminal and I can switch between "Implicit" profile and the new created profile as you can see in the below image:

Now I wonder how can I switch between profiles using a command-line/script or maybe using a shortcut for this.

Note: Solutions like:

gnome-terminal --tab-with-profile=Implicit && exit 

are excluded because I prefer not to close and open another terminal or get another terminal window in this process of changing the profile.

By default, Nautilus use/show the path bar:

Using Ubuntu Tweak I managed to set by default the address bar:

Is it possible to set both of them as default (show both: the buttons and the text input)?

Note: I know that I can use Ctrl+L to switch between them, so I'm not interested about this.

How can I run a specific command in terminal without to press Enter key after I typed the command?

How can I make a list with most used commands in terminal?

I know that this question may be unuseful for any future proposals for some of us, but even like this, the list can be useful when we don't remember a command used once or some times in the past, when we can search at the end of this list.

When running commands, sometimes maybe you need to run a command with the argument from the last command. How can you do this?

Of course, excepting the use of the arrow keys and Del keys: ↑←←←...←→→DelDelDel...Del<new_command>.

Sometimes, being rushed, it is possible to type some characters wrong in a command-line. If the command is long, the mistake correction may be cumbersome (using arrow keys). So the problem is: how can I replace characters typed wrong in the previous command as quickly as possible?

Update Manager keeps packages at the latest version, but occasionally a new package version may not work as expected or properly. How to downgrade an installed package and lock it at a specific version to prevent it from being updated? How can I do this using GUI or using a Terminal?

I know that in Windows, Internet Explorer stores .flv temp files in temporary folder (C:\Users\%username%\AppData\Local\Microsoft\Windows\Temporary Internet Files) when viewing YouTube. And the same make and Google Chrome in Windows (C:\Users\%username%\AppData\Local\Google\Chrome\User Data\Default\Cache). So it's easy to find a copy of that .flv file.

How about Chromium in Ubuntu? Does it store browsing temp data and where?

What can I do to run automatically a script after I mount/plugin or unmount/unplug a USB device?