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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34
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2answers
71k views

Updating Time : ntpdate[3108]: the NTP socket is in use, exiting

The time on my system is incorrect for some reason. i need to run an update but i can't seem to be able to this is the errror. ntpdate pool.ntp.org 31 Aug 12:31:59 ntpdate[3108]: the NTP socket is in ...
34
votes
6answers
90k views

play mp3 or wav file via Linux command line

I would like to make an alarm system backed by a Ubuntu (no graphical interface) box, which plays various announcement and alarm audio tracks (.mp3 or .wav) via the command line. For example: $ root&...
34
votes
2answers
4k views

How come one user can delete another user's 755 files?

I have a backup upload script that scp’s files to another server using the user upload. Another script on the target server then chown’s these to another user and sets the file mode to 755. If I then ...
34
votes
3answers
51k views

How to show output on terminal and save to a file at the same time?

I am using: user@unknown:~$ sudo command -option > log to save the results of "command" to the file "log", but I'd like to also get the result on the terminal, is this possible? I am using ...
34
votes
4answers
32k views

How do I find out what processes are accessing the hard disk in a GNU/Linux-based system?

I'm looking for the equivalent to top for disk access, so I can tell which process(es) are currently reading and/or writing to disk. I'm currently using Ubuntu, but I imagine there's a standard tool ...
34
votes
6answers
71k views

Bash script to delete files older than x days with subdirectories

I'm trying to delete a ton of files older than x days. Now I have a script to do that find /path/to/files* -mtime +10 -exec rm {} \; But this will also delete the subdirectories. There are a ton ...
34
votes
6answers
2k views

A more comfortable way to edit a long $PATH?

I want to add, in ~/.bashrc, a few directories to my $PATH. My $PATH is quite long so it's a bit hard to see what directories it contains and in what order. I know I can modify my ~/.bashrc to be: ...
34
votes
4answers
44k views

How to retrieve video file information from command line under Linux

I'd like to see from command line all informations pertaining to a given video file, including length, quality, bitrate, resolution, audio and video formats, number and language of audio streams and ...
34
votes
10answers
38k views

How to know which Linux Distribution I'm using?

How to know which Linux Distribution I'm using? uname -a gives Linux xxxxxx.net 2.6.9-42.0.3.EL.wh1smp #1 SMP Fri Aug 14 15:48:17 MDT 2009 i686 i686 i386 GNU/Linux How can I know this is Ubuntu/...
34
votes
3answers
15k views

Bad font anti-aliasing in Ubuntu

I'm switching from Fedora 8 to Ubuntu 9.04, and I can't seem to get it to get a good font anti-aliasing to work. It seems that Ubuntu's fontconfig tries to keep characters in integral pixel widths. ...
33
votes
16answers
85k views

How do I check whether I am using KDE or Gnome?

or maybe something else? I am using Redhat OS.
33
votes
4answers
23k views

Looping Through Subdirectories and Running a Command in Each

I have a set of repositories sorted into directories based on their VCS (Git, Mercurial, SVN). With Subversion I was able to run svn update * in the parent directory and it would loop through each ...
33
votes
2answers
36k views

Can GNU Grep output a selected group?

Is it possible to use GNU grep to get a matched group from an expression? Example: echo "foo 'bar'" | grep -oE "'([^']+)'" Which would output "'bar'". But I would like to get just "bar", without ...
33
votes
2answers
15k views

Linux: Is there something similar to “top” for I/O?

My disk often is utilized, but top (and htop, a custom replacement) show nothing suspicious. Is there a way to sort processes by I/O (more specific: disk) utilization? EDIT Found out using iotop ...
33
votes
2answers
48k views

Linux Bash Script, Single Command But Multiple Lines?

I have the following script I wrote by searching Google, and it backs up my Linux system to an archive: #!/bin/bash # init DATE=$(date +20%y%m%d) tar -cvpzf /share/Recovery/Snapshots/$HOSTNAME_$...
33
votes
5answers
12k views

Two keyboards on one computer. When I write with A I want a US keyboard layout, when I use B I want Swedish. Possible?

I have a laptop which I use an external keyboard with. When I type using the external keyboard I want to use a US keyboard layout, since that's the type of external keyboard I have. On the other hand, ...
33
votes
8answers
7k views

Is flash drive wear a significant issue?

My netbook has a flash drive instead of a hard disk drive, and I'm using Ubuntu Netbook Remix with ext3 as the file system. I've read some articles concerning flash drive wear, and the main concerns ...
33
votes
2answers
6k views

Is it possible to compile a Darwin Distro from source, like you can a build a Linux Distro?

I have read through and undertaken Linux From Scratch (and BLFS) and I was wondering, can I follow this guide to create a Darwin Distro by substituting the xnu kernel? Would the process be vastly ...
32
votes
5answers
5k views

Windows vs Linux Local Time?

Ever since I started using Linux in dualboot with Windows I noticed that when I rebooted the machine, the time on the other OS was wrong, e.g. it was 12:00 on Linux, then I rebooted and on Windows it ...
32
votes
8answers
21k views

Swap partition size on a 64 GB RAM computer for memory-intensive work

I have 64 GB RAM and 240 GB SSD on my computer, which I'm going to use for memory-intensive calculations (machine learning, data mining, etc.). Most of the advice I found on the Internet are ...
32
votes
5answers
3k views

Deleting millions of files

I had a dir fill up with millions of gif images. Too many for rm command. I have been trying the find command like this: find . -name "*.gif" -print0 | xargs -0 rm Problem is, it bogs down my ...
32
votes
8answers
57k views

How can I keep a process alive after closing the putty session?

I am using putty to interact with Linux server. I have started a process using putty. The process is running and will take 5-6 hours. I want that process to keep running after I close the putty ...
32
votes
4answers
59k views

yum install gcc-g++ doesn't work anymore in CentOs 6.4

Today installed CentOs 6.4 fresh new on my workstation. I wanted to install g++. With my surprise I didn't succeed by using yum install gcc-g++ The thing is that even by doing a search I don't ...
32
votes
4answers
42k views

How do I do a binary diff on two identically sized files under Linux?

I have two identically sized files, and I need to do a binary diff to check whether they're the same. I'm currently runnnig diff file1.img file2.img but it's taking quite a while to process my 4 ...
32
votes
2answers
35k views

How to find uptime of a linux process

How do I find the uptime of a given linux process. ps aux | grep gedit | grep -v grep gives me a whole lot of information which includes the time at which the process was started. I am specifically ...
32
votes
1answer
67k views

How can I filter out unique results from grep output?

In linux, I can grep a string from a file using grep mySearchString myFile.txt. How can I only get the result which are unique?
32
votes
4answers
21k views

How do I “identify with services” on IRC?

I am using irrsi as my irc cilent on ubuntu I have entered "/join #android-dev" in my command window. But I am getting this error message: 22:05 -!- #android-dev Cannot join channel (+r) - you need ...
32
votes
5answers
15k views

Sudo vs root; any actual differences?

I'm working with a support member for a product, and he insists that I need to be root to install a series of patches, and that sudo won't work; he doesn't provide a reason but seems very firm in his ...
32
votes
4answers
13k views

bash watch command with colors preserved

From man watch: Non-printing characters are stripped from program output. Use "cat -v" as part of the command pipeline if you want to see them. So how do I use cat -v if I want to see the ...
32
votes
3answers
28k views

How do I create a relative symbolic link in Linux?

I need a symlink that resolves relative to the directory it is placed in. What command is used to create such a thing?
32
votes
5answers
4k views

Does running commands verbosely make them slower?

I've found myself using the -v flag for lots of applications less and less (especially for trivial stuff like tar and cp). However, when I did and I was, say, unzipping a large file, it would take ...
32
votes
4answers
24k views

How to copy a file without using scp inside an ssh session?

I have logged on to a system with ssh and there is no scp present on both the systems. How to copy a file without using the scp program.
32
votes
1answer
37k views

How can I logout an open, remote SSH session?

I sshed into a Linux machine (bash shell) from a public Windows machine (in our lab) and forgot to log out. I'm now back at my seat in another room and I am too lazy to walk back and log out that ...
32
votes
2answers
63k views

How do I gunzip to a different destination directory?

How do I gunzip to a destination directory other than the current one? This did not work: gunzip *.gz /putthemhere/
32
votes
2answers
14k views

What's the difference between “adduser” and “useradd”?

I wonder: Why are there these two commands on Debian Linux, with very similar names and functionality? This has always been confusing for me. Is any of them superior to another? Why aren't they ...
32
votes
3answers
4k views

Can history files be unified in bash?

I routinely run multiple screen sessions on my Linux desktops and servers. A problem with this is that when I grep through my command history, I find I issued a command in a different session, and ...
32
votes
3answers
23k views

What is the difference between 'locate' and 'find' in Linux?

Why there are two so similar command in Linux? and normally what are the circumstances to use each of them?
31
votes
10answers
3k views

Prevent user typing accidental space between rm and wildcard

Intention: rm -rf string* Problem: rm -rf string * The first case is a legitimate and common use of rm, a small typo can cause a lot of problems in the second case. Is there a simple way to ...
31
votes
4answers
58k views

How to type special characters in Linux?

In windows there is possibility to type from keyboard special signs by holding alt key and typing a few numbers, that depends on with sign you want to use. Does it work with linux in the same way?
31
votes
6answers
50k views

how to download dropbox files using wget command?

Seems I can only download dropbox files using explorer such as chrome and firefox. If I use wget to download, then I would get a file which is in html format. Why? For example you can open this link ...
31
votes
5answers
35k views

How Do I Find The Hardware Block Read Size for My Hard Drive?

I'm trying to figure out the optimal size for a large copy from my hard drive using dd. I'm trying to figure out what the best blocksize to use it, which I would assume is the hardware block size for ...
31
votes
4answers
35k views

How can I install objdump on Mac OS X?

I want to get the source code of a small command line tool using objdump on Mac OS X. I've used arm-linux-objdump on Linux and find it a great tool. Is there any way to install objdump on OS X? I've ...
31
votes
4answers
53k views

Delete matching files in all subdirectories

How can I remove all .swp files in all of my subdirectories under Linux?
31
votes
6answers
14k views

/usr/local or /opt?

How do you generally proceed for your package installations on Linux, for packages that are not part of your distrib's repos? On my side I am used to install in /opt. But since, I saw this doc on the ...
31
votes
5answers
111k views

How can I add a regular user to the sudoers file?

How can I add more users to the "sudoers" file?
31
votes
7answers
43k views

Batch-convert files for encoding

How can I batch-convert files in a directory for their encoding (e.g. ANSI->UTF-8) with a command or tool? For single files an editor helps, but how to do the mass files job?
31
votes
4answers
38k views

How do you find the parent process of a zombie process?

How do you find the parent process of zombie processes? When the child process is something where the parent is not entirely obvious... Is there some way to list processes in tree format or ...
31
votes
1answer
86k views

How can I convert multiple files to UTF-8 encoding using *nix command line tools? [duplicate]

Possible Duplicate: Batch-convert files for encoding or line ending I have a bunch of text files that I'd like to convert from any given charset to UTF-8 encoding. Are there any command line ...
31
votes
9answers
56k views

Flow chart software for Linux? [closed]

Been using Visio at work to do flowcharts, and I'm liking how easy it is to do overall, notably creating and linking shapes. I'm trying to find something for Linux that works the same way, or at ...
31
votes
10answers
44k views

How to extract text with OCR from a PDF on Linux?

How do I extract text from a PDF that wasn't built with an index? It's all text, but I can't search or select anything. I'm running Kubuntu, and Okular doesn't have this feature.