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

learn more… | top users | synonyms

2
votes
2answers
308 views

How do I prevent a script from terminating when the shell exits?

In particular, I created a script to start Firefox which I double-click and choose 'Run in terminal,' but when the shell exits Firefox is killed immediately. How do I prevent this from happening?
2
votes
1answer
334 views

Is there a difference between Linux and Unix? [duplicate]

Possible Duplicate: Is Linux a Unix? Kind of confused by the two terms. Is there any difference between the two terms?
-1
votes
2answers
1k views

Is the linux directory structure obsolete and obtuse? [closed]

I genuinely feel that the Linux directory system presents an obstacle for users migrating from other systems as well as being a bottleneck for the evolution of Linux itself. Rest assured I am not here ...
12
votes
4answers
5k views

How to display meminfo in megabytes in top?

Sometimes it is not comfortable to see meminfo in kilobytes while you have several gigs of RAM. In Linux it looks like that: And here is how it looks in Mac OS X: Is there a way to display ...
10
votes
1answer
414 views

Why doesn't mount respect the read only option for bind mounts?

On my Arch Linux system (Linux Kernel 3.14.2) bind mounts do not respect the read only option # mkdir test # mount --bind -o ro test/ /mnt # touch /mnt/foo creates the file /mnt/foo. The relevant ...
10
votes
1answer
1k views

Who creates /etc/{group,gshadow,passwd,shadow}-?

In any linux system I have access to (a couple of Archlinuxes, an Ubuntu, a Debian Sid and a Gentoo) there are the following 4 files in /etc/, all ending with a dash: /etc/group- /etc/gshadow- ...
8
votes
2answers
1k views

Output ls -l size field with digits grouped by thousands?

It is possible to make ls -l output the size field with digits grouped by thousands? If so, how? For instance: $ ls -l -rw-rw---- 1 dahl dahl 43,210,052 2012-01-01 21:52 test.py (Note the commas ...
8
votes
3answers
3k views

Batch delete exif info

How can I recursively remove the EXIF info from several thousand JPG files?
8
votes
2answers
1k views

Detailed sparse file information on Linux

I have a sparse file, in which only some blocks are allocated: ~% du -h --apparent-size example 100K example ~% du -h example 52K example I would like to know which blocks of the file are ...
7
votes
2answers
229 views

Strange temporary network outage in Linux

I'm facing a very annoying problem that I noticed a week from now and for which I can't find an answer: my network suddenly stops responding, usually coming back exactly 25 seconds later. I was using ...
7
votes
1answer
604 views

Lightweight virtualization on Linux with user isolation

What Linux-on-Linux virtualization technologies provide user isolation? Specifically, I want root in the virtual machine not to have any privilege on the host. This was not the case for LXC, but was ...
6
votes
1answer
2k views

top output: cpu usage > 100%

Here is the top output which I gathered: I noticed that top is showing vlc's cpu usage is > 100%. Can anybody please justify me why it is showing like this, whether this is a bug in top ...
5
votes
3answers
388 views

What exactly do we mean when we say we are using Linux?

I was going through an article on GNU which goes something like below There really is a Linux, and these people are using it, but it is just a part of the system they use. Linux is the kernel: ...
5
votes
2answers
28k views

Boot windows from grub rescue command prompt

Previously I had installed the Ubuntu 10.04 and Windows 7. Now I logged on to Windows, opened thepartition editor and deleted the volume containing the Ubuntu (Thought it will delete the Ubuntu and ...
5
votes
3answers
143 views

Use of ./ in running the compiled code

Why do we use ./ before running a compiled code in linux? It does not seem to necessary if I am in a directory higher than the one having compiled code. Let me explain by example. If my code is in ...
5
votes
3answers
875 views

What are the advantages of the Unix file system structure

If I install an application in Linux for example Debian/Gnu Linux, the files of the applications are copied to many different directories in the file system. Some scripts goes into /usr/share .. ...
5
votes
3answers
3k views

How do I “merge” two text files?

I recently upgraded from Ubuntu 12.04 to 12.10 and at one point, it encountered an Apache config file conflict in apache2.conf. I didn't give me a merge option at that point, so I just rejected the ...
5
votes
1answer
439 views

What are the main differences between Unix and Linux kernels today?

I know that many of the same programs run flawlessly on top of both kernels. I know that historically, the two kernels came from different origins. I know philosophically too that they stood for ...
5
votes
0answers
98 views

How can different file descriptors point to the same file in open file table? [duplicate]

Possible Duplicate: How can same fd in different processes point to the same file? I have a hard time grasping the two ideas of File Descriptor Table and Open File Table. Open File Table ...
5
votes
2answers
5k views

Cleancache vs zram?

I have an old laptop here with only 512 MB of RAM. Since a few kernel releases, I am using zram to convert 256 MB of it to a compressed ramdisk which is then used as swap. This has proved to be very ...
5
votes
1answer
904 views

How to be notified when a USB device was plugged?

My system have to auto-mount for usb devices, how can I be notified when a usb device is plugged? Where can I read more about? I would like to treat that using shell script or C.
4
votes
4answers
706 views

Help me choose the right distribution for learning and hosting web apps

I'm coming to Linux from the Windows world, and I want to learns the ins and outs of the system in order to make it my primary day to day work and hosting environment. I'm pretty much a complete ...
4
votes
2answers
358 views

Knowing Privilege rights on a file in Linux

i wanted to know the Read / Write Access on to a file , so i did this way ls -l Denem.sh This command displayed -rwxr-xr-x 1 pavan employee 672 DEC 20 2000 pavan.sh Could anybody please tell ...
4
votes
2answers
716 views

How do I get most of my standard Linux utilities and commands on Android 3.1?

By standard, I mean just what users often get by default with one of the popular distros. For example, uname, finger, vim, tmux, etc. I have a Galaxy Tab 10.1 (Android version 3.1, already rooted) ...
4
votes
3answers
1k views

Permissions issues for shared directory on a server

The setup is we have a VPS running Debian Squeeze, and I've set up a shared directory for us to share files. So far I've followed this guide: ...
4
votes
2answers
1k views

Remapping caps-lock to escape, and menu to compose, on the linux console

When running X I use a .xmodmaprc to remap certain keys thusly: ! Make it so that both Caps Lock and Escape do Escape clear Lock keysym Caps_Lock = Escape ! Remap the menu key as Compose keysym Menu ...
3
votes
1answer
289 views

How does the Linux file structure work?

I see the different folders bin, dev, mnt, proc, srv, sys, etc. What are the properties of all these different folders? What are there purposes? Are there files in some of them that I should not ...
3
votes
2answers
3k views

How to connect two computers via internet with ssh?

I want to connect another computer via internet that doesn't have a public IP. Is there any away to do this?
3
votes
1answer
1k views

LVM2 partition alignment

How to do the following with Linux tools : LVM partition alignment and alignment of partition on LVM ? What in case where I want to setup LVM partition (for "pv") and then partitions ? To be more ...
3
votes
2answers
2k views

256 color in real console

I have in my .bashrc export TERM=xterm-256color but this cause blinking all colored text (ls --color, in vim etc.) in real console (CTRL + ALT + F1) . So is there any possibility to recognize in ...
3
votes
1answer
647 views

Bootable USB appearing as HDD not Removable Device

I have a unique problem with an older Toshiba satellite laptop that happens to be a LegacyFree laptop meaning you can't access the bios via the normal F2, Del, Esc, etc. I can only select a boot ...
3
votes
1answer
2k views

Multiple SSH chaining (tsocks, socksify, proxycommand, etc. )

http://i.stack.imgur.com/YTOvt.png Goal: you need to reach "Server B" from the Client "directly" with SSH, SCP. "Server B" is next to "Server A". E.g.: they're on the same subnet, but only "Server ...
3
votes
1answer
2k views

How to change font-size, number of rows / columns on a terminal

I am running a Linux server (without xwindows or any kind of GUI), with a modern 22" LCD monitor. Given the huge size of my monitor, I would like to increase the number of rows and columns on my ...
2
votes
2answers
54 views

What environment and credential is used by startup, background and service processes

Startup scripts (on boot) Processes running in (or sent to) the background (when using SSH -fN for example) Services etc... What $path variable will they be using? What credentials? Anything else I ...
2
votes
2answers
2k views

How to change the output redirection of a running process?

I know how to redirect output and how to suppress them in bash. Now, suppose I accidentally forgot to append the output redirection part to the command (e.g. 2>&1 or > /tmp/mystdout) and my ...
2
votes
5answers
719 views

What do these commands mean?

What would be a more straight forward readable way of these commands? And why exit 255 and not exit 1? [ $# -eq 3 ] || { echo error ; exit 255 ; } grep -q "string" && exit 0
2
votes
5answers
4k views

How do I resize a partition in Ubuntu linux without losing data?

I ran out of space in my on the drive only to find that there was another unformatted partition in the system that is available. I now want to resize the current partition to take in the empty ...
2
votes
3answers
879 views

Is there a linux vfs tool that allows bind a directory in different location (like mount --bind) in user space?

For a user process, I want to mount a directory in other location but in user space without root privilieges. Something like mount --bind /origin /dest, but with a vfs wrapper. Like a usermode ...
1
vote
2answers
103 views

Changing user to root when connected to a linux server and copying files

My script is coded in a way that doesn't allow you to connect to a server directly by root. This code basically copies files a server to my computer and it works but I don't have access to many files ...
0
votes
2answers
154 views

setfacl access issues

I have a list of users (user1,user2,user3,superuser). user1, user2 and user3 belong to a usergroup called normalusers . Now, I need to issue the access control list command for the user superuser to ...
6
votes
1answer
4k views

Group within group file permissions

I tried finding this on here, but couldn't so sorry if it's a duplicate. Say I have 2 groups and a user: group1, group2, user1 with the following structure: group1 is a member of group 2, user1 is a ...
6
votes
1answer
579 views

Linux kernel 3.3 power regression

I am using Fedora 16 in my DELL n4110. I recently upgraded the kernel from 3.2 to 3.3. In contradiction to the official claim, my system still drains battery as hell. It only provides 1:30 to 2 hrs of ...
6
votes
3answers
2k views

xorg memory leaks

On my desktop Xorg leaks a lot of memory. I use to let this machine on for days (weeks, months ...), but about once a week I'm forced to restart xorg, because it is taking too much memory. Am I the ...
6
votes
2answers
2k views

Will the system make sure that mdadm is sync-ed before completing a reboot?

This is a follow up to my crazy mdadm problem. I'm trying to figure out what might have caused sda to get out of sync in the first place. The only thing I can think of is that I had just run a bunch ...
5
votes
1answer
98 views

Using ACL with Multiple Default Groups

I have looked though the answers to similar questions and refreshed my memory on ACLs by reading tutorials on Linux ACLs. Yet, I am still stumped. What have I done wrong, or what do I not understand? ...
5
votes
1answer
198 views

Linux: What is a tainted kernel?

Under certain conditions, the Linux kernel may become tainted. For example, loading a proprietary video driver into the kernel taints the kernel. This condition may be visible in system logs, kernel ...
5
votes
1answer
334 views

Swapping <esc> and <caps lock> in a way that persists with external keyboards

I have a file called ~/.speedswapper which contains the following: ! Swap caps lock and escape remove Lock = Caps_Lock keysym Escape = Caps_Lock keysym Caps_Lock = Escape add Lock = Caps_Lock ...
5
votes
2answers
477 views

Turning off swapping for only one process with cgroups?

I would like to turn off swapping for only one process. Swap should work as usual for the other processes. How I can implement this with cgroups?
5
votes
1answer
133 views

Permanent Environment Variable for all users

I want to have all users on the system to have an environment variable named SPI that points to /usr/local/share_ideas directory. How do I do it?
5
votes
2answers
2k views

What's the default order of linux sort?

For a long period I think the default behavior of sort program is using ASCII. However, when I input the following lines into sort without any arguments: # @ I got: @ # But according to the ...