A symlink works more closely to the first way you described it. The software opening a symlink has to actually follow it. It’s possible for a software to not follow the symlink (either intentionally or not).

So your sync software has to actually be able to follow symlinks. I’m not familiar with how gdrive and similar solutions work, but I know this is possible with something like rsync

A symlink is a file that contains a shortcut (text string that is automatically interpreted and followed by the operating system) reference to another file or directory in the system. It’s more or less like Windows shortcut.

If a symlink is deleted, its target remains unaffected. If the target is deleted, symlink still continues to point to non-existing file/directory. Symlinks can point to files or directories regardless of volume/partition (hardlinks can’t).

Different programs treat symlinks differently. Majority of software just treats them transparently and acts like they’re operating on a “real” file or directory. Sometimes this has unexpected results when they try to determine what the previous or current directory is.

There’s also software that needs to be “symlink aware” (like shells) and identify and manipulate them directly.

You can upload a symlink to Dropbox/Gdrive etc and it’ll appear as a normal file (probably just very small filesize), but it loses the ability to act like a shortcut, this is sometimes annoying if you use a cloud service for backups as it can create filename conflicts and you need to make sure it’s preserved as “symlink” when restored. Most backup software is “symlink aware”.

Software opens a symlink the same way as a regular file. The kernel reads a path stored in a symlink and then opens a file with that path (or returns a error if unable to do this for some reason). But if a program needs to perform specific actions on symlinks, it is able to check the file type and resolve symlink path.

To determine how some specific software handle symlinks, read its documentation. It may have settigs like “follow symlinks” or “don’t follow symlinks”.

ELI5: when a computer stores something like a file or a folder, it needs to know where it lives and where its contents are stored. Normally where the a file or folder lives is the same place as where its contents are. But there are times where a file may live in one place and its contents are elsewhere. That’s a symlink.

So for your video example, the original video is located in Downloads so the video file will say I am movie.mp4 and I live i live in downloads, and my contents are in downloads. While the symlink says, I am movie.mp4 I live in home, and my contents are in downloads over there.

For a video player, it doesn’t care if the file and the content is in the same place, it just need to know where the content lives.

Now how software will treat a symlink as an absolute. For example if you have 2 PCs synced with cloud storage, and both downloads and home is being synced between your 2 pcs. Your cloud storage will look at the symlink, access the content from pc1 and put your movie.mp4 in pc2’s downloads and home. But it will also put the contents in both places in pc2 since to it, the results are the same. One could make software sync without breaking the symlink, but it depends on the developer and the scope of the software.

Whenever I open the symlink, does the software (player) understand «oh this file seems like a symlink, I should go and open the original file», or it’s a filesystem level stuff and software (player) basically has no idea if a file I’m opening is a symlink or the original movie.mp4?

Others have answered well already, I just will say that symlinks work at the filesystem level, but the operating system is specially programmed to work with them. When a program asks the operating system to open a file at a given path, the OS will automatically “reference” the link, meaning it will detect a symlink and jump to the place where the symlink is pointing.

A program may choose to inspect whether a file is a symlink or not. By default, when a program opens a file, it simply allows the operating system to reference the file path for it.

But some apps that work on directories and files together (like “find”, “tar”, “zip”, or “git”) do need to worry about symlinks, and will check if a path is a symlink before deciding whether to reference it. For example, you can ask the “find” command to list only symlinks without referencing them: find -type l

its a pointer.

E: Okay so someone downvoted “it’s a pointer”. Here goes. both hard links and symbolic links are pointers.

The hard link is a pointer to a spot on the block device, whereas the symbolic link is a pointer to the location in the filesystems list of shit.

That location in the filesystems list of shit is also a pointer.

So like if you have /var/2girls1cup.mov, and you click it, the os looks in the file system and sees that /var/2girls1cup.mov means 0x123456EF and it looks there to start reading data.

If you make a symlink to /var/2girls1cup.mov in /bin called “ls” then when you type “ls”, the os looks at the file in /bin/ls, sees that it points to /var/2girls1cup.mov, looks in the file system and sees that it’s at 0x123456EF and starts reading data there.

If you made a hard link in /bin called ls it would be a pointer to the location on the block device, 0x123456EF. You’d type “ls” and the os would look in the file system for /bin/ls, see that /bin/ls means 0x123456EF and start reading data from there.

Okay but who fucking cares? This is stupid!

If you made /bin/ls into /var/2girls1cup.mov with a symlink then you could use normal tools to work with it, looking at where it points, it’s attributes etc and like delete just the link or fully follow (dereference) the link and delete all the links in the chain including the last one which is the filesystems pointer to 0x123456EF called /var/2girls1cup.mov in our example.

If you made /bin/ls into a hardlink to 0x123456EF, then when you did stuff to it the os wouldn’t know it’s also called /var/2girls1cup.mov and when /bin/ls didn’t work as expected you’d have to diff the output of mediainfo on both files to see that it’s the same thing and then look where on the hard drive /var/2girls1cup.mov and /bin/ls point to and compare em to see oh, someone replaced my ls with a shock video using a hard link.

When you delete the /bin/ls hardlink, the os deletes the entry in the file system pointing to 0x123456EF and you are able to put normal /bin/ls back again. Deleting the hard link wouldn’t actually remove the data that comprises that file off the drive because “deleting” a “file” is just removing the file systems record that there’s something there to be aware of.

If instead of deleting the /bin/ls hardlink, you opened it up and replaced the video portion of its data with the music video to never gonna give you up, then when someone tried to open /var/2girls1cup.mov they’d instead see that music video.

if that is, the file wasn’t moved to another place on the block device when you changed it. Never gonna give you up has a much longer running time than 2girls1cup and without significant compression the os is gonna end up putting /bin/ls in a different place in the block device that can accommodate the longer data stream. If the os does that when you get done modifying your 2girls1cup /bin/ls into rickroll then /bin/ls will point to 0x654321EF or something and only you will experience astleys dulcet tones when you use ls, the old 0x123456EF location will still contain the data that /var/2girls1cup.mov is meant to point to and you will have played yourself.

Okay with all that said: how does the os know what to do when one of its standard utilities encounters a symlink? They have a standard behavior! It’s usually to “follow” (dereference) the link. What the fuck good would a symbolic link be if it didn’t get treated normally? Sometimes though, like with “ls” or “rm” you might want to see more information or just delete the link. In those cases you gotta look at how the software you’re trying to use treats links.

Or you can just make some directories and files with touch and try what you wanna do and see what happens, that’s what I do.

deleted by creator

Symlinks are fully transparent for all software just opening the file etc.

If the software really cares about this (like file managers) they can simply ask the Linux kernel for additional information, like what type of file it is.

I understand sudo needs a password

You can configure sudo to not need a password for certain commands. Unfortunately the syntax and documentation for that is not easily readable. Doas which can be installed and used along side sudo is easier.

For software updates you can go for unattended-upgrades though if you turn off your computer when it is upgrading software you may have to fix the broken pieces.

You can configure this behavior for CLI, and by proxy could run GUI programs that require elevation through the CLI:

https://wiki.archlinux.org/title/Sudo#Using_visudo

Defaults passwd_timeout=0(avoids long running process/updates to timeout waiting for sudo password)

Defaults timestamp_type=global (This makes password typing and it’s expiry valid for ALL terminals, so you don’t need to type sudo’s password for everything you open after)

Defaults timestamp_timeout=10(change to any amount of minutes you wish)

The last one may be the difference between having to type the password every 5 minutes versus 1-2 times a day. Make sure you take security implications into account.

I understand sudo needs a password,but all the other stuff I just want off.

Sudo doesn’t need a password, in fact I have it configured not to on the computers that don’t leave the house. To do this open /etc/sudoers file (or some file inside /etc/sudoers.d/) and add a line like:

nibodhika ALL=(ALL:ALL) NOPASSWD:ALL

You probably already have a similar one, either for your user or for a certain group (usually wheel), just need to add the NOPASSWD part.

As for the other parts you can configure the computer to not lock the screen (just turn it off) and for updates it depends on distro/DE but having passwordless sudo allows you to update via the terminal without password (although it should be possible to configure the GUI to work passwordless too)

The things you listed can be customized.

Disable screen lock and it stops locking. This is a setting in gnome, probably in KDE, maybe in others.

Polkit can allow installing and updating in packagekit (like gnome software) without the password. I think this is default in Fedora, at least for the user marked as administrative. openSUSE actually has a gui for changing some of these privileges in the Security and Hardening settings.

Passwords are meant to protect against using privileged processes as the user. This comes from a very traditional multi-user system, where users should not touch the system.

If the actions that require authentication are supported by polkit (kde shows the ID when expanding the message) you can add a policy file in /etc/polkit-1/rules.d/

Take this file as an example

Asking the real question here. I hope there is a one way solution per application. But I doubt it. I hope you don’t get the usual answer that it’s “absolutely necessary” for security.

For wake from screensaver/sleep, this should be configurable. Your window manager is locking your session, so you probably just need to turn that option off.

For installations and updates, I suspect you’re used to Windows-style UAC where it just asks you Yes or No for admin access in a modal overlay. As I understand it, this is easier said than done on linux due to an insistence on never running GUI applications as admin, which makes sense given how responsibilities are divided and the security and technical challenges involved. I will say, I agree 100% that this is a serious area that’s lacking for linux, but I also (think I) understand why no one has implemented something similar to UAC. I’ll try to give the shortest version I can:

All programs (on both Windows and Linux) are run as a user. It’s always possible for any program to have a bug in it that gives another program to opportunity to exploit the bug to hijack that program, and start executing arbitrary, malicious code as that user. For this reason, the philosophical stance on all OSes is, if it’s gonna happen, let’s not give them admin access to the whole machine if we can avoid it, so let’s try to run as much as possible as an unprivileged user.

On linux, the kernel-level processes and admin (root-level) account are fundamentally detached from running anything graphical. This means that it’s very hard to securely, and generically, pop up a window with just a Yes or No box to grant admin-level permissions. You can’t trust the window manager, it’s also unprivileged, but even if you could, it might be designed in a supremely insecure way, and allow just any app with a window to see and interact with any other app’s windows (Xorg), so it’s not safe to just pop up a simple Yes/No box, because then any other unprivileged application could just request root permissions, and then click Yes itself before you even see it. Polkit is possible because even if another app can press OK, you still need to enter the password (it’s not clear to me how you avoid other unprivileged apps from seeing the keystrokes typed into the polkit prompt).

On windows, since the admin/kernel level stuff is so tightly tied to the specific GUI that a user will be using, it can overlay its own GUI on top of all the other windows, and securely pop in to just say, “hey, this app wants to run as admin, is that cool?” and no other app running in user mode even knows it’s happening, not even their own window manager which is also running unprivileged. The default setting of UAC is to just prompt Yes/No, but if you crank it to max security you get something like linux (prompt for the password every time), and if you crank it to lowest security you get something closer to what others are commenting (disable the prompt, run things as root, and cross your fingers that nothing sneaks in).

I do think that this is a big deal when it comes to the adoption of linux over windows, so I would like to see someone come up with a kernel module or whatever is needed to make it happen. If someone who knows linux better than me can correct me where I’m wrong, I’d love to learn more, but that is how I understand it currently.

These are all valid reasons to request a password 🤔

• Wake computer from Screensaver? Password.

Check your screen saver settings. Dunno which desktop environment you’re using. KDE should allow you to not enter a password for this.

• Install something? Password.
• Updates (biggest one. Updates should in my opinion just work without, because being up to date is important for security reasons)? Password.

Installing stuff runs sudo in the background hence the password prompt. Updates = installing stuff. Look up “passwordless sudo”. At this point, when do you even want a password to be shown? If you don’t need a password, get rid of it entirely.

Someone already gave an answer, but the reason it’s done that way is because on Linux, generally programs don’t install themselves - a package manager installs them. Windows (outside of the windows store) just trusts programs to install themselves, and include their own uninstaller.

Because Linux and the programs themselves expect specific files to be placed in specific places, rather than bunch of files in a single program directory like you have in Windows or (hidden) MacOS.

If you compile programs yourself you can choose to put things in different places. Some software is also built to be more self contained, like the Linux binaries of Firefox.

you install program A, it needs and installs libpotato then later you install program B that depends on libfries, and libfries depends on libpotato, however since you already have libpotato installed, only program B and libfries are installed The intelligence behind this is called a package manager

In windows when you install something, it usually installs itself as a standalone thing and complains/reaks when dependencies are not met - e.g having to install Visual C++ 2005-202x for games, JRE for java programs etc

instead of making you install everything that you need to run something complex, the package manager does this for you and keep tracks of where files are

and each package manager/distribution has an idea of where some files be stored

I wish every single app installed in the same directory. Would make life so much easier.

Expanding on the other explanations. On Windows, it’s fairly common for applications to come with a copy of everything they use in the form of DLL files, and you end up with many copies of various versions of those.

On Linux, the package manager manages all of that. So if say, an app needs GTK, then the package manager makes sure GTK is also installed. And since your distribution’s package manager manages everything and mostly all from source code, you get a version of the app specifically compiled for that version of GTK the distribution provides.

So if we were to do it kind of the Windows way, it would very, very quickly become a mess because it’s not just one big self contained package you drop in C:\Program Files. Linux follows the FSH which roughly defines where things should be. Binaries go to /usr/bin, libraries to /usr/lib, shared files go to /usr/shared. A bunch of those locations are somewhat special, for example .desktop files in /usr/share/applications show up in the menu to launch them. That said Linux does have a location for big standalone packages: that’s usually /opt.

There’s advantages and inconveniences with both methods. The Linux way has the advantage of being able to update libraries for all apps at once, and reduce clutter and things are generally more organized. You can guess where an icon file will be located most of the time because they all go to the same place, usually with a naming convention as well.

Because dependencies. You also should not be installing things you download of the internet nor should you use install scripts.

The way you install software is your distros package manager or flatpak

different strokes.

windows comes from the personal computing world and retains a bunch of stuff from it to this very day for no good reason, in this case there used to be no guarantee that a particular installation target would have the target directory mapped in a consistent way so the installer would make a guess and give the user a chance to change it.

if that sounds stupid, it is. no one writes in assembly anymore, they target the OS and nowadays the OS will have a consistent set of folders to install stuff to. we all know where the program “should” be installed to already.

but it didn’t used to be like that in the PC world! used to be your computer wasn’t a fixed purpose windows computer from the jump, never to be anything else. there were different OSes that people would use regularly and even different DOS environments which a person could use to run programs under. Hard disks weren’t disks inside the machine, but big beige external disks that you’d plug up, set beside the computer and access after booting. in that setup where a programmer targeted DOS (if they cared about the execution environment at all and didn’t just write for the processor) it made sense to ask where someone was gonna want to install their software, and to what extent they’d even want to start dirtying up the media they paid good money for with some knuckleheads weird files from some goofy program on a stack of floppy disks.

linux comes from the unix world, where the question of where something installs is easy and straightforward: it installs in $PATH. what is $PATH? it’s where the os will look when you try to run something to see if it can run any program by that name. if a program isn’t installed in $PATH then when you type its’ name in and hit enter the computer won’t know what the hell youre talking about and you’ll have to type it’s whole ass location out and hit enter.

Why didn’t unix systems that linux imitates ask you where to install stuff? because usually it wasn’t your choice! linux was unix for personal computers and unix was run on systems that took up whole rooms with all sorts of equipment. you might be the user of that system but never have access to the room with all the spinning disks and flashing lights, stuck on a terminal dialing in over a serial line.

so the assumption was that you’d have a variable in your user environment that would say where things were installed but not that you’d have the ability to change it or even install things.

so why in a linux environment would you ever install anything outside of $PATH or even want to be sure where something’s installed at all?

even under linux it can be useful to do either. installing outside of path keeps programs from being accidentally autocompleted or invoked. installing in a particular component of $PATH ($PATH can be many directories!) lets you put serious business programs that demand maximum performance on faster media.

so why the hell won’t linux systems give you the option of installing in a specific location or outside of $PATH altogether?

they will, but unlike windows, they don’t ask you. unless you specifically ask to do that unique and very abnormal operation, they just do the usual thing. when you want to install weirdly you gotta dig into your package manager and packaging system. sometimes you unzip a package and change a line in a file then zip it back up and install from your modified version.

/bin, since that will include any basic programs (bash, ls, cd, etc.).

As in, the directory in which much of the operating system’s executable binaries are contained in?

They’ll be spread between /bin and /sbin, which might be symlinks to /usr/bin and /usr/sbin. Bonus points is /boot.

For the memes:

sudo rm -rf /*

This deletes everything and is the most popular linux meme

The same “expected” functionality:

sudo rm -rf /bin/*

This deletes the main binaries. You kinda can recover here but I have never done it.

There is no direct equivalent, system32 is just a collection of libraries, exes, and confs.

Some of what others have said is accurate, but to explain a bit further:

Longer explanation:

The basics:

• /bin - base level executables, ls, mv, things like that
• /sbin - super-level-only (root) executables, parted, reboot, etc
• /lib - Somewhat self-explanatory, holds libraries, lots of things put their libs here, including linux kernel modules, /lib/modules/*, similar to system32’s function of holding critical libraries
• /etc - Configuration lives here, generally speaking, /etc/<application name> can point you in the right direction, typically requires super-user (root) to edit
• /usr - “User installed” software, which can be a murky definition in today’s world, but lots of stuff ends up here for installed software, manuals, icon files, executables

Bonus:

• /opt - A special location, generally third-party, bundled-style software likes to use this, Java for instance, but historically some admins use it as the “company location”, meaning internally developed software would live there.
• /srv - Largely subjective, but myself and others I know use it for partitions that are outside the primary disk, for instance we use /srv/db for database volumes, /srv/www for web-data volumes, /srv/Media for large-file storage, etc, etc

For completeness:

• /home - You’ll find your user directories here, personally, this is my directory I backup, I don’t carry much more with me on most systems.
• /var - “Variable data”, basically meaning any data that will likely grow over time, eg: /var/log

Don’t think there is.

system32 holds files that are in various places in Linux, because Windows often puts libraries with binaries and Linux shares them.

The bash in /bin depends on libraries in /lib for example.

What is system32? Outdated 32bit binaries?

/usr/lib or /usr/lib64 or /lib (some distros) or /lib64

Some things (like hosts file) are in /etc. /etc mostly contains configs.

The terminal world has Ctrl+C and Ctrl+(many other characters) already reserved for other things before they ever became standard for copy paste. For for this reason, Ctrl+Shift+(C for copy, V for paste) are used.

In Terminal land, Ctrl+C has meant Cancel longer than it’s meant copy. Shift + Insert does what you think Ctrl+V will do.

Also, there’s a separate thing that exists in most window managers called the Primary buffer, which is a separate thing from the clipboard. Try this: Highlight some text in one window, then open a text editor and middle click in it. Ta da! Reminder: This has absolutely nothing to do with the clipboard, if you have Ctrl+X or Ctrl+C’d something, this won’t overwrite that.

Old timer here! As many others replying to you indicate, Ctrl+C means SIGINT (interrupt running program). Many have offered the Ctrl+Shift+C, but back in my day, we used Shift+Insert (paste) and Ctrl+Insert (copy). They still work today, but Linux has 2 clipboard buffers and Shift+Insert works against the primary.

As an aside, on Wayland, you can use wl-paste and wl-copy in your commands, so git clone "$(wl-paste)" will clone whatever repo you copied to your clipboard. I use this one all the time

Does Ctrl+Shift+V work?

Try ctrl+shift+v, iirc in the terminal ctrl+v is used as some other shortcut (and probably has been since before it was standard for “paste” I’d bet).

Also linux uses two clipboards iirc, the ctrl+c/v and the right click+copy/paste are two distinct clipboards.

What usually also works on Linux is selecting text with the mouse and pasting it by pressing the middle mouse button (or scroll wheel). You’d still need the mouse, but it’s at least a little quicker ☺️

In most terminal (gnome terminal, blackbox, tilix etc.) you can actually override this behavior by changing keyboard shortcut. Blackbox even have a simple toggle that will enable ctrl+c v copy paste.

Gnome console is the only terminal I know that doesn’t allow you to change this.

Due to some old school terminal things. Add shift to shortcut combinations, such as Ctrl+Shift+V to paste.

You need to use Ctrl+shift+v

Try Shift+Insert. That’s my preferred pasting method in most scenarios.

deleted by creator

…because that would make Ctrl+C Cut/Copy and that would be really bad. It would kill whatever was running.

So, it becomes Ctrl+Shift+C and paste got moved in the same way for consistency.

Ctrl+shift+V is what you should do. Ctrl+V is used by shells for I believe inserting characters without doing some sort of evaluation. I don’t remember the specifics though, but yes Ctrl+shift+V to paste.

While I don’t have the answer as to why, it usually works if you just add a shift, ie. SHIFT+CTRL+V Many terminals also allow you to change the shortcut to copy and paste, so you can adjust for comfort’s sake.

This is a really great question and it was something that tripped me up back in the day!

The answers above cover it already, so upvoting hoping it’s more visible. Thanks for asking it. :)

Use shift+control+v to paste. Shift+control+c to copy in the terminal. It’s this way because control+c in the terminal is to break out of the currently running process.

Shift + insert

Ctrl+V is already a shortcut for something (I don’t even know what) but to paste just add shift so Ctrl+Shift+V.

(Also a beginner btw)