Questions specifically about Linux, as opposed to Unix-like systems in general, or to questions about a specific distribution or program.

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16
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5answers
1k views

Where does uname get its information from?

Where does uname really get its information from? I figure this is something that should be straightforward. Unfortunately, I can't find any header containing just that information. Say someone ...
16
votes
4answers
2k views

What happens if you edit a script during execution?

I have a general question, which might be a result of misunderstanding of how processes are handled in Linux. For my purposes I am going to define a 'script' as a snippet of bash code saved to a text ...
16
votes
2answers
1k views

Why is JFS so obscure?

When I first got into using Slackware years ago I quickly learned to love JFS over ext3 or reiserfs given that it was reliable and if there was an unclean shutdown, its disk checking was very very ...
16
votes
3answers
5k views

File system compatible with all OSes?

I use Linux and Mac OS X on a regular basis, and sometimes I have to use Windows. I need to use a flash drive on all three, and I need a filesystem that will work well on all of them. None of the ...
16
votes
4answers
3k views

Block network access of a process?

Is it possible to block the (outgoing) network access of a single process?
16
votes
1answer
815 views

How to automate Linux server configuration?

Is there any way to automate Linux server configuration? I'm working on setting up a couple of new build servers, as well as an FTP server, and would like to automate as much of the process as ...
16
votes
5answers
1k views

What constitudes a 'field' for the cut command?

For example, the cut command can take a parameter -f, which according to man select only these fields; also print any line that contains no delimiter character, unless the -s ...
16
votes
4answers
15k views

How can I tell what version of linux I'm using?

Often times I will ssh into a new client's box to make changes to their website configuration without knowing much about the server configuration. I have seen a few ways to get information about the ...
16
votes
4answers
4k views

Block Particular Command in Linux for Specific user

How to block command, let say mkdir for specific user ? What I did just created read-only function and store in users profile ~/.bashrc /bin/mkdir() { echo "mkdir command not allow for you" ...
16
votes
2answers
2k views

When was a process started

To know when was a process started, my first guess was to check the time when /proc/<pid>/cmdline was written/modified the last time. ps also shows a START field. I thought both of these ...
16
votes
3answers
14k views

Where can I see a list of kernel killed processes?

Is there some way I can check which of my processes the kernel has killed? Sometimes I log onto my server and find that something that should've run all night just stopped 8 hours in and I'm unsure if ...
16
votes
1answer
512 views

How is new hardware support added to the linux kernel?

Imagine there's a company A that releases a new graphics adapter. Who manages the process that results in this new graphics adapter being supported by the Linux kernel in the future? How does that ...
16
votes
2answers
3k views

How does one change the delay that occurs after entering an incorrect password?

After entering an incorrect password at a login prompt, there s an approximately 3-second delay. How can I change that on a Linux system with PAM?
16
votes
4answers
917 views

Linux adoption path for a .NET developer [closed]

I am a .NET C# programmer, I love the .NET stack. I have tried Linux several times but every time I got put off as I could not do anything on it .. (like program for it or on it). Ever since Mono was ...
16
votes
1answer
2k views

What is maximum RAM supportable by Linux?

What is the maximum supportable RAM by Linux? Assume that hardware is/supports 64-bit. Among all Linux distros. Does it go up to 16 exabytes, or is it limited like with Windows which I believe is 192 ...
16
votes
1answer
15k views

How to skip “permission denied” errors when running find in Linux? [duplicate]

Possible Duplicate: How do I remove “permission denied” printout statements from the find program? When I run this command in Linux (SuSE): find / -name ant I get many error ...
16
votes
2answers
45k views

What user should apache and PHP be running as? What permissions should /var/www files have?

I just spun up an Ubuntu 11.10 box and then ran apt-get install apache2 php5 to install apache2 and PHP 5 on the box. Now it is functioning as a "web server" and it loads the "It Works!" page. Now I'm ...
15
votes
10answers
26k views

List partition labels from the command line

Is there a command that will list all partitions along with their labels? sudo fdisk -l and sudo parted -l don't show labels by default. EDIT: (as per comment below) I'm talking about ext2 labels - ...
15
votes
5answers
3k views

Why do most linux distros default gnome?

Why the default desktop environment of most popular linux distros is gnome? KDE seems to me an equally good desktop environment. Is it for licence reason? historic? or else?
15
votes
4answers
633 views

What is new in Kernel 3.0?

I understand this is somewhat less Ubuntu related, but it affects it. So,what is so new about it that Linus decided to name it 3.0? I'm not trying to get information about the drivers that got into ...
15
votes
3answers
8k views

How can I reserve a block of memory from the Linux kernel?

I have a device that needs a block of memory that is reserved solely for it, without the OS intervening. Is there any way to tell BIOS or the OS that a block of memory is reserved, and it must not ...
15
votes
4answers
2k views

How is the linux graphics stack organised?

Can anybody explain(hopefully with a picture), how is the linux graphics stack organised? I hear all the time about X/GTK/GNOME/KDE etc., but I really don't have any idea what they actually do and how ...
15
votes
2answers
1k views

Why writing to /dev/random does not make parallel reading from /dev/random faster?

Typically reading from /dev/random produces 100-500 bytes and blocks, waiting for an entropy to be collected. Why doesn't writing information to /dev/random by other processes speed up reading? ...
15
votes
5answers
8k views

Using different versions of Python

Background: Since I develop python programs that must run on different python versions, I have installed different versions of python on my computer. I am using FC 13 so it came with python 2.6 ...
15
votes
2answers
10k views

Get the chmod numerical value for a file

In FreeBSD and also in Linux, how can I get the numerical chmod value of a file? For example, 644 instead of -rw-r--r--? I need an automatic way for a Bash script.
15
votes
2answers
8k views

How to Determine the Amount of RAM Slots In Use?

I forgot how many RAM modules are installed on my laptop. I do not want to unscrew it but want to look it up on the console. How do I gather this information?
15
votes
4answers
16k views

What's the best way to join files again after splitting them?

If I have a large file and need to split it into 100 megabyte chunks I will do split -b 100m myImage.iso That usually give me something like xaa xab xac xad And to get them back together I have ...
15
votes
3answers
4k views

How to fix Ctrl + arrows in Vim?

I am using Putty -> Suse box -> vim 7.2 combo for editing and want to remap Ctrl + arrows combo to a particular task. But for some reason, Vim ignores the shortcut and goes into insert mode and ...
15
votes
2answers
283 views

Open man page and search for string in a single command

Instead of doing man chmod and then /a+x to jump to the first section in the chmod man page that mentions a+x, I would like to know if there is a way to open the man page to a specific search string, ...
15
votes
5answers
3k views

Can ps display only non kernel processes on Linux?

How can I ask ps to display only user processes and not kernel threads? See this question to see what I mean...
15
votes
6answers
294 views

What do I need to be aware of if I want to write an application that will run on any Linux distro?

I'm planning on writing an app that I would like to be able to run on any Linux installation without having to rewrite any of the code in doing so (except maybe the interface, GNOME vs KDE, etc). I'm ...
15
votes
5answers
3k views

How to start a new Linux distro?

Some of my friends and I are interested in starting a new Linux distro. How do we do that? What do we need to plan? Backstory I represent a community of Linux sysadmins/implementors whose special ...
15
votes
7answers
10k views

Linux boot loaders supporting full disk encryption?

Are there any Linux boot loaders supporting full disk encryption (a la TrueCrypt). I know there was work towards adding encryption support to GRUB2, but this does not seem to be ready yet. Any other ...
15
votes
2answers
439 views

Can I list the filesystems a running kernel can support?

I'm trying to detect what filesystems a kernel can support. Ideally in a little list of their names but I'll take anything you've got. Note that I don't mean the current filesystems in use, just ones ...
15
votes
1answer
3k views

per process swapiness for linux

/proc/sys/vm/swappiness is nice but i want a knob that's per process like /proc/$PID/oom_adj so that i can make certain processes less likely than others to have any of their pages swapped out unlike ...
15
votes
2answers
1k views

Linux: Total swap used = swap used by processes +?

So, I'm trying to do some investigation on where does swap use come from in a system with high swap usage: # free total used free shared buffers cached Mem: ...
15
votes
2answers
10k views

Booting native Arch Linux on an Android device

I have a Galaxy Note 10.1 (n8010) and I want to make it boot Arch Linux natively. I mean boot Arch Linux instead of android. All that I need is to alter the initramfs, which I can't find anywhere in ...
14
votes
3answers
966 views

Why do Linux people always say to read the manual? [closed]

Why do Linux people always say to read the manual when it would be so much easier to just give you an answer? There's no manual! It didn't come with one.
14
votes
2answers
1k views

Accidently created a file called -X, how can I delete it? [duplicate]

Possible Duplicate: How do I delete a file whose name begins with “-” (hyphen a.k.a. dash or minus)? Like an idiot, I ran this command: tar -cf -X awstats-icon icon ...
14
votes
5answers
6k views

What is the difference between ls and l?

I accidentally typed l instead of ls today and found that the command still printed a list of the files in my current directory. Trying l --help brings up the help file for ls suggesting that l is ...
14
votes
4answers
969 views

Why not always use rsync?

I wanted to ask is there any reason not to use rsync for everything and abandon cp? I wasn't aware of rsync and now I don't know why cp is ever needed.
14
votes
10answers
2k views

What linux is best suited for people new to computers?

What would be the easiest linux for people who are new to computers? The computers here have 256Mb RAM with 40GB hard-disks. UPDATE: Most of them apparently have more than 265MB of RAM with some ...
14
votes
5answers
12k views

How can I limit the bandwidth used by a process?

I have a CentOS 5.7 server that will be backing up its files nightly. I am concerned that visitors to the various sites that the server hosts will experience degraded performance while the backup is ...
14
votes
3answers
700 views

Move files and change ownership at the sametime

On Linux (Debian, Ubuntu Mint...), Is there any option command or something that I can use to transfer files to another user without having to do : sudo mv /home/poney/folderfulloffiles ...
14
votes
8answers
9k views

How to determine which sd* is usb? [duplicate]

Possible Duplicate: How to know if /dev/sdX is a connected USB or HDD? The output of ls /dev/sd* on my system is - sda sda1 sda2 sda3 sda4 sda5 sda6 sda7 sdb sdc sdc1 sdc2 ...
14
votes
6answers
10k views

Execute a specific command in a given directory without cd'ing to it?

Is there a way to execute a command in a different directory without having to cd to it? I know that I could simply cd in and cd out, but I'm just interested in the possibilities of forgoing the extra ...
14
votes
6answers
5k views

How does Linux kernel compare to microkernel architectures?

I read once that one advantage of a microkernel architecture is that you can stop/start essential services like networking and filesystems, without needing to restart the whole system. But considering ...
14
votes
3answers
2k views

Why don't you need to update drivers? (Or do you?)

In my life I've not once updated drivers on any of my Linux systems, though they have all been desktops. A friend was asking me why one does not need to update Linux drivers and I found myself unable ...
14
votes
10answers
52k views

Cannot enable network after CentOS 6.3 fresh install

I am trying to perform a fresh CentOS 6.3 installation then run various yum commands such as yum install httpd. The installation runs fine, however I cannot run any network based commands like yum I ...
14
votes
2answers
6k views

/proc/PID/fd/X link number

In Linux, in /proc/PID/fd/X, the links for file descriptors that are pipes or sockets have a number, like: l-wx------ 1 user user 64 Mar 24 00:05 1 -> pipe:[6839] l-wx------ 1 user user 64 Mar 24 ...