Linux refers to the family of Unix-like computer operating systems using the Linux kernel. If your question is about a certain distribution only, use a more specific tag.
1115
votes
8answers
123k views
How do I make a machine “blank screen” for a period of time (as a penalty) if certain noise levels are reached?
My kids (4 and 5) yell a lot when playing games on computer. I found an effective cure for this. I ssh into game computer and do:
chvt 3; sleep 15; chvt 7
when I hear loud noises. This will turn ...
206
votes
7answers
123k views
How can I sort the output of 'ls' by last modified date?
How can I sort the output of ls by last modified date?
I can't find the answer on Google without digging around, an there is no answer on Stack Overflow either.
140
votes
17answers
8k views
What is the advantage of using 'tar' today?
I know that tar was made for tape archives back in the day, but today we have archive file formats that both aggregate files and perform compression within the same logical file format.
Questions:
...
116
votes
5answers
5k views
What do the parentheses and number after a Unix command or C function mean?
I keep seeing parentheses and a number after a command in Unix or Linux or C function.
For example: man(8), ftok(2), mount(8), etc.
What do these mean? I see them in man too.
95
votes
5answers
6k views
How do identify whether my Linux computer was hacked?
My home PC is usually on, but the monitor is off. This evening I came home from work and found what looks like a hack attempt: in my browser, my Gmail was open (that was me), but it was in compose ...
90
votes
3answers
163k views
How to find a directory on linux?
I have a VPS with Suse Linux 10.3.
I've logged in via SSH/putty and am trying to find where my web files are located.
Since I'm uploading via FTP in a directory called httpdocs, I assume that this ...
76
votes
13answers
100k views
How can I download an entire website?
How can I download all pages from a website?
Any platform is fine.
68
votes
12answers
19k views
Undo an “rm -rf ~” command?
I had a folder I didn't want named '~', so from the command line I typed
rm -rf ~
and accidentally deleted my home folder (since ~ resolved to /home/username). Is there any way back or do I ...
68
votes
4answers
13k views
Why does Ctrl + V not paste in Bash (Linux shell)?
When I copy something to the clipboard and press Ctrl + V in Bash, nothing happens; However, right clicking and selecting Paste does the job.
Why? Is there any reasonable issue (I'm sure there is) ...
67
votes
6answers
36k views
How to chmod 755 all directories but no file (recursively)?
How to chmod 755 all directories but no file (recursively) ?
Inversely, how to chmod only files (recursively) but no directory ?
62
votes
5answers
21k views
Which linux filesystem works best with SSD
From wiki:
The vital TRIM function is supported by the Linux OS starting with 2.6.33 kernel (available early 2010). However, support amongst various filesystems is still inconsistent or not present. ...
59
votes
6answers
28k views
What is the “You have new mail” message in Linux/UNIX?
Sometimes, when I log into a box and 'su' to root, I get a cute little message saying I have mail (thank GOD it's not AOL).
Where is this mail?
What does it contain?
Who/What sent it?
How important ...
58
votes
13answers
4k views
How to delete all files in a directory except some?
I need to delete all files in a directory, but exclude some of them. For example, in a directory with the files a b c ... z, I need to delete all except for u and p. Is there an easy way to do this?
57
votes
13answers
6k views
How is Linux not prone to viruses, malware and those kinds of things?
How is Linux protected against viruses?
I am not a cracker, it is just out of curiosity that I am asking this question.
This question was a Super User Question of the Week.
Read the blog ...
56
votes
13answers
5k views
Is Unix not a PC operating system?
I am doing my bachelor's degree at a university. In a written assignment, the professor posted the task: "Name three PC operating systems".
Well, I went on an included a variety of OSes (Linux, ...
56
votes
9answers
42k views
How do I detach a process from Terminal, entirely?
I use Tilda (drop-down terminal) on Ubuntu as my "command central" - pretty much the way others might use GNOME Do, Quicksilver or Launchy.
However, I'm struggling with how to completely detach a ...
56
votes
5answers
3k views
What are the functions of the BIOS while the operating system is running?
I always wondered whether the BIOS (apart from conducting POST, starting the bootloader and passing control to the OS after one presses the power button) has any purpose or function while the ...
53
votes
6answers
33k views
How do you gunzip a file and keep the .gz file?
The default behavior of gunzip is to delete the .gz file after it decompresses.
How do I prevent it from deleting the file??
If this functionality is not included then is there an alternative ...
50
votes
5answers
2k views
How do perform commands in another folder, without repeating the folder path?
I was wondering if there's any clever way to do copy and move operations, or if there's a command to duplicate a file, without having to do a cd, then mv after, at the same folder.
For example, I ...
50
votes
5answers
16k views
Aptitude vs. apt-get: Which is the recommended (aka the “right”) tool to use?
Some time ago I read that aptitude is the preferred tool for installation on Debian-based systems. But when you search around on how to administer a Debian-based system, then aptitude is rarely ...
49
votes
4answers
3k views
Is a file system just the layout of folders?
I have used Windows since childhood, and when I hear the phrase "Windows filesystem" I think of directories (folders) within directories, a folder called SYSTEM, a folder called PROGRAM FILES etc. Is ...
49
votes
5answers
2k views
How to “unextract” a zip file?
I extracted a zip file into a non-empty folder. The zip file has lots of files and a deep hierarchy, that merged with the existing tree of the target directory. How can I remove the files and ...
48
votes
9answers
100k views
How do I get an entire directory in sftp?
I'm just learning to use sftp, and I want to copy a directory from the remote computer to my local computer. If I try
get [directory]
it gives me this error:
Cannot download non-regular file: ...
46
votes
3answers
9k views
How to turn off word-wrap in less
Short version:
How can I make the less utility in Linux not wrap lines?
Long version:
Often I need to view huge CSV files using less with hundreds of columns. I frequently only care about the first ...
45
votes
8answers
22k views
How to reliably keep an SSH tunnel open?
I use an SSH tunnel from work to go around various idotic firewalls (it's ok with my boss :)). The problem is, after a while the ssh connection usually hangs, and the tunnel is broken.
If I could at ...
44
votes
4answers
38k views
How do I find out what version of Linux I'm running?
Is there a way to determine what version (distribution & kernel version, I suppose) of Linux is running (from the command-line), that works on any Linux system?
44
votes
3answers
10k views
What is the difference between shell, console, and terminal?
I'm confused with the terminology. What is the difference between shell, console, and terminal?
42
votes
2answers
21k views
Go back to previous directory in shell
Is there a way to go back to previous directory we were in using bash,tcsh without using pushd/popd ?
I'd like to type something like "back" and got returned to the previous directory I was in.
Edit:
...
41
votes
12answers
126k views
How do I get Java support on Google Chrome in Linux?
Is there a way to run Linux Google Chrome with Java support?
40
votes
9answers
72k views
How to wipe free disk space in Linux?
When a file is deleted, its contents may still be left in the filesystem, unless explicitly overwritten with something else. "wipe" can securely erase files, but does not seem to allow erasing free ...
40
votes
4answers
34k views
chown is not changing symbolic link
I'm trying to change the user/group of a symbolic link with the command:
$ chown -h myuser:mygroup mysymbolic/
But it's not changing. I'm logged in as root. The current user/group is set to ...
39
votes
5answers
101k views
How can I give write-access of a folder to all users in linux?
I installed apache2 on Ubuntu just now, and noticed that the /var/www folder is protected. I can just sudo everything but I would rather just give it write access.
How can I do this?
I tried sudo ...
39
votes
5answers
42k views
How to get the summarized sizes of folders and their subfolders?
Let's say I want to get the size of each folder of a linux file system. When I use ls -la I don't really get the summarized size of the folders.
If I use df I get the size of each mounted file system ...
39
votes
2answers
16k views
Finding the process that is using a certain port in Linux
I'd like to be able to find out which process is currently using a certain port in Linux. Is there any way to do this?
37
votes
7answers
11k views
Better Ubuntu Fonts
I have been using Ubuntu for a while. I like it. I like it a lot.
But once in a while, when I switch to Windows, I feel better because I really like the font. It feels really much pleasant to watch ...
36
votes
9answers
52k views
Linux: How to move all files from current directory to upper directory?
I tried something like mv . .. but it doesn't work.
36
votes
5answers
114k views
How to install real Firefox on Debian?
Debian 6 ("Squeeze") uses a rebranded version of Firefox called Iceweasel. It however lacks plugin support, most of my favorites don't work.
So what is best way to install the "real" Firefox on ...
35
votes
7answers
12k views
Get colors in 'less'' command
when I read a file in Linux with the command 'less' or 'more', how can I get the content in colors?
35
votes
3answers
16k views
What's the equivalent of Linux's updatedb command for the Mac?
If I want to use the locate command on a Linux machine, I usually run sudo updatedb first to update the database. I can run the locate command on OS X 10.5 but I can't find updatedb. What's the ...
35
votes
3answers
40k views
ps aux output meaning
When typing ps aux, what does each column of the output mean? For example
$ ps aux
timothy 29217 0.0 0.0 11916 4560 pts/21 S+ 08:15 0:00 pine
root 29505 0.0 0.0 38196 2728 ? ...
34
votes
8answers
1k views
How do you configure a Windows machine for a Linux user?
How do you configure a Windows (preferably latest version) machine for a Linux power user, so that s/he can get most out of it?
Mod note: if all you have to add is a one-liner, your answer will be ...
33
votes
12answers
3k views
How do I remove a file in Linux whose name looks like it's ONLY a hyphen, as in “-”
I've tried
rm -- -
rm "-"
rm "\-"
rm \-
Gave Perl a shot
~$ perl -e '$junk = glob("-"); chomp $junk; print "$junk\n"; `rm $junk`;'
-
rm: cannot remove `-': No such file or directory
...and...
...
33
votes
8answers
2k views
Why is Bash everywhere (in most if not all Linux distributions)?
Bash is used by default in every Linux distribution I have tried, over alternatives like Z shell (zsh). Is there a technical or historical reason for this?
33
votes
14answers
71k views
How do I figure out which /dev is a USB flash drive?
I want to mount a USB drive, two of them and I need two different mount points. Unfortunately, the Linux kernel underwent a name change and I can't figure out which /dev location is the right one. Is ...
33
votes
4answers
55k views
How can I list all IPs in the connected network, through Terminal preferably?
Using Ubuntu 10.10, I was wondering if there was a command line command that can list all the IPs of devices connected to the network?
I would use this for example, to list all the computers ...
33
votes
3answers
2k views
Palindrome passwords disallowed—why?
I tried to change a Linux password to "sitonapotatopanotis" and got this error: BAD PASSWORD: is a palindrome
Why does this rule exist?
32
votes
3answers
41k views
No option to hibernate/shutdown in GNOME 3?
I have installed Fedora 15 Alpha with GNOME 3. Everything is working fine. However, I can't see any option to hibernate or shutdown.
In the top panel when I click my user name, I only have one option ...
31
votes
13answers
23k views
Linux utility for finding the largest files/directories
I'm looking for a program to show me which files/directories occupy the most space, something like:
74% music
\- 60% music1
\- 14% music2
12% code
13% other
I know that it's possible in KDE3, but ...
31
votes
6answers
2k views
Linux equivalent of Windows Registry
What is the Linux equivalent of Windows Registry? If there is no equivalent or similar structure in Linux, how are the things that are done by the Windows Registry handled in Linux?
31
votes
1answer
2k views
If I buy a computer with Windows 8 and Secure Boot, will I still be able to install Linux?
I've heard a lot about how Microsoft is implementing UEFI Secure Boot in Windows 8. Apparently it prevents "unauthorized" bootloaders from running on the computer, to prevent malware. There's a ...
