A family of Unix-like operating systems using the Linux kernel. If your question is about a certain distribution only, use a more specific tag.

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48
votes
11answers
17k views

What's a good solution for file-tagging in linux?

I've been looking for a way to tag my files and search/filter them based on those tags. Here are my (updated) requirements : any file readable by the user can be tagged freely a user can search ...
47
votes
9answers
73k views

How can you see the actual hard link by ls?

I run ln /a/A /b/B I would like to see at the folder a where the file A points to by ls.
47
votes
4answers
73k views

What is effect of CTRL + Z on a unix\Linux application

I was curious and confused that what exactly is the behaviour of CTRl+Z. I know, If a process in running in foreground, and we press ctrl+z, it goes to background. But what exactly happens. Does it ...
47
votes
6answers
124k views

How do I restart Linux (Ubuntu) from the command-line?

Because of my problem with mouse-clicks being ignored in Ubuntu, I want to restart from the command-line. (I have an open Terminal, and the keyboard is not ignored.) How do I restart a computer ...
47
votes
3answers
88k views

How do I create a 1GB random file in Linux?

I am using the bash shell and would like to pipe the out of the command openssl rand -base64 1000 to the command dd such as dd if={output of openssl} of="sample.txt bs=1G count=1. I think I can use ...
47
votes
9answers
93k views

How to get parent PID of a given process in GNU/Linux from command line?

Resolved before asked: cat /proc/1111/status | grep PPid
47
votes
1answer
34k views

logrotate configuration file syntax - multiple wildcard entries possible?

Since the man page doesn't answer my question and I don't want to force a rotation cycle, I decided to ask the question here. The man page for logrotate gives the following example: "/var/log/...
47
votes
1answer
10k 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 ...
46
votes
7answers
79k views

How to list folders using bash commands?

Is there any way to list just the folders in a directory using bash commands? ( as the ls command lists all the files and folders )
46
votes
5answers
67k views

How to determine available free space on Ubuntu?

I am in a situation where I am getting an error when I try to save a file to my Ubuntu server via ssh. It says there isn't any available space left. I don't know how that can be true. What should I do ...
46
votes
5answers
102k views

mount dev, proc, sys in a chroot environment?

I'm trying to create a Linux image with custom picked packages.What I'm trying to do is to hand craft the packages I'm going to use on an XO laptop, because compiling packages takes really long time ...
46
votes
7answers
20k views

What happens if mv is interrupted?

What happens if the Linux mv command is interrupted? Say, I'm moving a whole directory to some other place and interrupt it while it's moving. Will the source directory still be untouched?
46
votes
6answers
30k 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 ...
46
votes
3answers
8k views

How urgent is a *** System restart required *** for security?

To learn a bit of server administration I've set up a simple Ubuntu 14.04 server on which I run a personal website. I've set it to automatically install security updates, but leave out the other ...
45
votes
4answers
44k views

How to wget a file with correct name when redirected?

So after some time of searching on Google and Super User (and scanning man pages) I was unable to find an answer to something that (I think) should be simple: If you go here: http://www.vim.org/...
45
votes
3answers
21k views

Convert a PDF to greyscale on the command line in FLOSS?

I have a colour PDF file, and I'm going to print it out and then photocopy it in black and white. I'd like to know what it's like in B&W before photocopying it. Is it possible to 'greyscale' a PDF ...
45
votes
3answers
54k views

Obtain kernel config from currently running Linux system?

I accidentally deleted my .config for my kernel configuration on Linux, and seem to remember there was a way to retrieve the kernel configuration via the proc filesystem somehow. Is this still ...
45
votes
8answers
95k views

Remove file without asking

How can I remove file without asking user if he agrees to delete file? I am writing shell script and use rm function, but it asks "remove regular file?" and I really don't need this. Thank you.
45
votes
5answers
26k views

How do I configure SSH so it dosen't try all the identity files automatically?

I have been putting my ssh identity files inside my ~/.ssh/ folder. I have probably about 30 files in there. When I connect to servers, i will specify the identity file to use, with something like ...
45
votes
6answers
27k views

Getting macro keys from a Razer BlackWidow to work on Linux

I picked up a Razer BlackWidow Ultimate that has additional keys meant for macros that are set using a tool that's installed on Windows. I'm assuming that these aren't some fancypants joojoo keys and ...
45
votes
7answers
17k 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?
45
votes
4answers
26k views

Is there a way to find out what application using most of bandwidth in Linux?

I'm looking for an utility that could show me how much of a bandwidth each process are using. It should just print the data and exit as I want to feed that list into conky.
45
votes
2answers
76k views

Where does Google Chrome for Linux store user specific data?

Where does Google Chrome for Linux store user specific data such as bookmarks ? I can't find a .chrome or .google directory under my home directory, any other directory I should look at ?
45
votes
6answers
150k views

How do I select all text from a file with nano?

I open a file in Ubuntu nano editor from the comand line and I want to copy all the contents of the file so I can paste it in an another application outside the shell. So far I can only copy using ...
44
votes
9answers
3k views

How to quickly change the first word in a Bash command?

I would like to improve my workflow a bit with Bash, and I realize I often want to execute the same command to a different executable. Some examples: Git (where I would like to quickly change the ...
44
votes
7answers
70k views

Copy entire file system hierarchy from one drive to another

I would like to copy the entire file system hierarchy from one drive to another..i.e contents of each directory as well as regular files in Linux platform. Would be gratefull to know the best way to ...
44
votes
5answers
17k views

tmux disregarding the configuration file

I just installed tmux on Ubuntu 10.04 and tried to remap the prefix key to C-a by creating the file ~/.tmux.conf with these lines: set-option -g prefix C-a unbind-key C-b When starting tmux, both ...
44
votes
3answers
70k views

How to get list of dependencies of non-installed RPM package?

apt-cache show <package> shows also it's dependencies. yum info <package> does not show dependencies, but it obviously know them. How to ask yum for dependencies of specified package?
44
votes
6answers
28k views

How do I get ls --color=auto to work on Mac OS X?

I'm trying to move my bash configuration from Ubuntu to Mac OS X and it looks like ls is slightly different. For instance, it won't accept the --color option. How do I get this to work?
44
votes
5answers
28k views

How do I execute multiple commands when using find?

I'm trying to run multiple commands on things I have found, how can I achieve this? find . -exec cmd1; cmd2 does not seem to work; it instead runs cmd2 after cmd1 has been executed on every file.
43
votes
9answers
5k 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?
43
votes
8answers
265k views

How to set current time on Linux?

Why is the output of the following commands different? root@vmi2115:/var# hwclock Sun 26 Jun 2011 01:21:38 PM CEST -0.273230 seconds root@vmi2495:/var# date Sun Jun 26 15:21:39 CEST 2011 root@...
43
votes
4answers
103k views

How do you set a password for transmission-daemon, the BitTorrent client server?

The config file is ambiguous, and keeps getting overwritten when you restart the daemon in Debian, anyway. In /etc/transmission-daemon/settings.json, there are these options: rpc-username rpc-...
43
votes
4answers
29k views

How to make cut/copy/paste in GVim on Ubuntu work with Ctrl+X,Ctrl+C,Ctrl+V?

By default, the cut/copy/paste short-cuts in GVim on Ubuntu are: Cut "+x Copy "+y Paste "+gP I would like to use control key combos in GVim, like I use in Firefox and othe gnome ...
43
votes
3answers
13k views

In Linux, how do I truncate command-line output?

If I grep -nr sumthin * in my source code directory, it also spews out very long lines from minified JavaScript or CSS files. I want to get just the first 80 characters per line. For example, a ...
42
votes
2answers
7k views

what is the difference between “command && command” and “command ; command”

I see these two usage on Ubuntu "command && command" and "command ; command", e.g. apt-get update && apt-get upgrade What would differ if I use apt-get update; apt-get upgrade? I ...
42
votes
9answers
76k views

How to auto detect text file encoding?

There are many plain text files which were encoded in variant charsets. I want to convert them all to UTF-8, but before running iconv, I need to know its original encoding. Most browsers have an ...
42
votes
9answers
32k views

Linux: Compare Directory Structure Without Comparing Files

What is the best and simplest way to compare two directory structures without actually comparing the data in files? This works fine: diff -qr dir1 dir2_ But it's really slow because it's comparing ...
42
votes
2answers
18k views

What's the difference between “su” with and without hyphen?

I'm quite new to Linux terminal and I'm not quite sure what the difference between su with a hyphen and su without a hyphen is, for example: su - username vs. su username. I looked into the ...
41
votes
5answers
74k views

How do I get the size of a Linux or Mac OS X directory from the command-line? [duplicate]

What command do I use to find the size of all the files (recursively) in a Linux or Mac OS X directory?
41
votes
1answer
123k views

Give write permissions to multiple users on a folder in Ubuntu

There is a folder that is owned by user tomcat6: drwxr-xr-x 2 tomcat6 tomcat6 69632 2011-05-06 03:43 document I want to allow another user (ruser) write permissions on document folder. The two ...
41
votes
6answers
41k views

Uploading files to S3 account from linux command prompt

I've got several large files sitting in my linux hosted account that I need to upload to my S3 account. I dont want to download them first and then upload it into S3. Is there any way I can "upload" ...
41
votes
9answers
156k views

What is the shell command to display contents of a file?

Like that of .txt or .html
41
votes
3answers
8k views

How to rate-limit a pipe under linux?

Is there a filter which I could use to rate-limit a pipe on linux? If this exists, let call it rate-limit, I want to be able to type in a terminal something like cat /dev/urandom | rate-limit 3 -k | ...
41
votes
3answers
109k views

How can I clear the IP address of Ethernet interface without cycling the interface up/down or restarting it

What is the Linux command to clear IP address of an interface without bringing it down and/or restarting network services. Seems strange ifconfig is able to change IP address but has no option to ...
41
votes
3answers
31k views

Ubuntu shutdown fail “* Killing all remaining processes…”

I have a fresh installation of Ubuntu Server. "reboot" works, but shutdown fails on the * Killing all remaining processes... step. I am using: sudo shutdown now After the failure, indicated by [...
41
votes
3answers
39k views

Why is the CPU usage reported by top in Linux over 100%?

I've seen the CPU usage go over 100%. How is this possible? Is it because I have four CPU cores, so 100% isn't really the max? Also, when a program does this, what else can I do in top besides using ...
41
votes
5answers
24k views

How to use different network interfaces for different processes?

I have two network interfaces on a Linux PC, and I need to manually set the interface that a given process will use. The program (Twinkle softphone) does not have a similar option, so I believe that ...
41
votes
3answers
21k views

Does rm -f follow symbolic links?

I have a directory like this: $ ls -l total 899166 drwxr-xr-x 12 me scicomp 324 Jan 24 13:47 data -rw-r--r-- 1 me scicomp 84188 Jan 24 13:47 lod-thin-1.000000-0.010000-0.030000.rda drwxr-...
41
votes
2answers
57k views

Can I create an SSH user which can access only certain directory?

I have a Virtual Private Server which I can connect to using SSH with my root account, being able to execute any linux command and access all the disk area, obviously. I would like to create another ...