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22
votes
2answers
4k views

Where is the fork() on the fork bomb :(){ :|: & };:?

Warning: Running this command in most shells will result in a broken system that will need a forced shutdown to fix I understand the recursive function :(){ :|: & };: and what it does. But I don'...
4
votes
1answer
126 views

Tomoyo Linux: Have a private folder, that can't be read by default

Is it possible to specify folders, eg: /home/$user/private that can not be listed, read or written to by any application in the default profile 0, but only with programs where I specify this as rule?...
3
votes
1answer
957 views

Compile the Ubuntu “Raring” Kernel with the Intel Compiler

Of course, the first question is: why I'm doing this. Just for fun! I'm learning more about Linux kernels and I have a virtual machine that I can replace in 15 minutes. Getting to business, I don't ...
2
votes
3answers
922 views

How to ensure File System is Mounted with ' atime ' enabled ?

Let's run mount /dev/mapper/VolGroup-lv_root on / type ext4 (rw) proc on /proc type proc (rw) sysfs on /sys type sysfs (rw) devpts on /dev/pts type devpts (rw,gid=5,mode=620) tmpfs on /dev/shm type ...
1
vote
1answer
396 views

Access time is not being updated when i run ` ls a ` and then ` stat a`

On CentOS Linux desktop let's create a folder named a. mkdir a Then let's access it ls a and then let's get it's statistics stat a File: `a' Size: 4096 Blocks: 8 IO Block: ...
1
vote
2answers
2k views

The command ` ls -ltu ` fails to list folders/files based on last accessed time

First on your linux desktop create 2 folders. a b Now run this in the terminal ls -ltu the result is drwxr-xr-x 2 root root 4096 Aug 30 20:33 b drwxr-xr-x 2 root root 4096 Aug 30 20:33 a Let'...
2
votes
0answers
184 views

Possible to limit number of cups printers?

The way I have configured CUPS on my workstation is by echo 'CUPS_SERVER=cups.example.com' >> ~/.profile echo 'export CUPS_SERVER' >> ~/.profile When I open the print menu in any ...
1
vote
0answers
181 views

How to change login screen size, Linux Mint

So I have been using linux mint for a little bit now. One thing that really bugs me is that the login screen size is always really small. I have used xrandr --output VGA1 --primary 1600x900 to set to ...
2
votes
0answers
2k views

openwrt firewall - block a set of ip addresses from internet access

I'm running OpenWRT Attitude Adjustment r33556 / LuCI Trunk (trunk+svn9325) on my WNDR3800. I would like to configure my firewall to: Only allow a specific range of IP addresses to access internet, ...
2
votes
4answers
270 views

Transforming text to tabular form

I have a text file with the following structure: aaa bbb ccc ddd eee fff 1 2 3 4 5 6 1.1 1.2 1.3 1.4 1.5 1.6 ggg hhh iii jjj kkk lll 7 8 9 10 11 12 2.1 2.2 2.3 2.4 2.5 2.6 and I want the ...
2
votes
2answers
153 views

How to get rid of power failure problems while using Linux?

I am using Linux. My daily working directory is present on a VFAT partition of my disk. Always I mount it and do my work. When power failure happens this directory sometimes gets corrupted and 'file ...
4
votes
1answer
9k views

What is the IPV4_FAILURE_FATAL ifcfg directive and under what scenarios would I want to use it?

CentOS / RHEL 6 I recently learned that there's a ifcfg directive called IPV4_FAILURE_FATAL exists for use in the files located here: /etc/sysconfig/networking-scripts/ifcfg-*. But I'm having a ...
1
vote
1answer
1k views

Using archlinux on vmware error 8000

I have been playing around with Linux a bit and I wanted to try using Arch Linux so I downlaoded the .iso and I set up vmware player saying that it was another Linux 2.6x kernel. As soon as I launched ...
2
votes
1answer
127 views

Why don't I see a file being copied right away with ls?

Is it due to the buffering in memory? I did cp /network/large_file . & and I kept doing ls -lh to monitor progress, but the file didn't appear until it was about 400MB. Linux 2.6 kernel, Bash 4, ...
-1
votes
1answer
3k views

How to create a GUI in shell script without any third party libs just like setup command [closed]

How to create a GUI in shell script without any third party libs (like setup command)
2
votes
1answer
726 views

Linux: I need to create installer for my own application using shell script

Linux: I need to create installer for my own application using shell script. I need to distribute my application as installer without GUI and also not as rpm's or any other packages. My application ...
2
votes
1answer
351 views

Atime value changing only once after file creation

I've mounted disk with explicit given value - atime: mount -o mount -o atime /dev/disk1 /myDisk then I've created a file by touch file_A after this operation stat output looks like that: Access:...
7
votes
1answer
734 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 ......
1
vote
0answers
36 views

Setting up a shared folder with group: ACL and file creation [duplicate]

I'm very new to ACL, and at the moment I've been trying to set up a shared folder such that any user belonging to a certain group (lets call it "thegroup") can have full access to the folder (which ...
3
votes
1answer
2k views

How to 'free' a TCP port?

I have some code that listens to a specific TCP port. However, when I stop this code and restart it quickly afterwards, I see the error ERROR: could not bind to socket on 0.0.0.0:7700 If I wait a ...
64
votes
3answers
34k views

Why is swappiness set to 60 by default?

I just read some stuff about swappiness on Linux. I don't understand why the default is set to 60. According to me this parameter should be set to 10 in order to reduce swap. Swap is on my hard ...
2
votes
1answer
123 views

Why does apt-get remove only a few kB?

I installed nginx (sudo apt-get install nginx) and then removed it with sudo apt-get remove nginx. I to need ensure that the application is uninstalled and cannot run. (I'm still able to run service ...
0
votes
1answer
171 views

Something very strange happen to my server today

If I type cd ~username it will say Can't find /home2/username Actually ~username exists, in /home3, and it used to work. Nothing strange has happened. Somehow Linux thinks that all of my /home2 ...
1
vote
1answer
6k views

Is there any way to check df -k hanging for nfs mount issues?

I am trying to write a script for such failure scenarios. In a scenario where maybe, if remote connection is lost, df waits for the remote server to respond (looks like df is hanging). I know I could ...
64
votes
3answers
551k views

How to check OS and version using a Linux command [duplicate]

What is the Linux command to check the server OS and its version? I am connected to the server using shell.
3
votes
2answers
914 views

SELinux: allow a process to create any file in a certain directory

I have a script that, when invoked, will cause the contents of dmesg to be written to a file, with the file's name basically being a timestamp. SELinux prevents this. Following the advice of Fedora'...
1
vote
1answer
140 views

Unstable network on integrated Debian environment

Good afternoon, I recently installed Debian Wheezy (7.0) on a freescale board (SABRE MCIMX6Q / iMX6Q) and discovered some disturbing lags for all network communications. What I have tried so far was ...
0
votes
2answers
798 views

Should I change SSD?

Demsg shows this EXT4-fs error (device sda1): ext4_ext_get_blocks: inode #7743113: (comm flush-8:0) bad extent address iblock: 3503, depth: 1 pblock 0 EXT4-fs (sda1): delayed block allocation failed ...
12
votes
5answers
5k views

Using grep or awk

To capture a particular pattern, awk and grep can be used. Why should we use one over the other. How does this work in the background? Which is faster and why? E.g If I had a log file and I wanted ...
20
votes
4answers
6k 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 ...
1
vote
2answers
169 views

Backing up a large file

I have a test running which crashes. I need to find out how far it reached before crashing. It will restart again after crashing and wipe the log file. This wiping takes 10 minutes though. So If I'm ...
1
vote
2answers
2k views

Hugepages in linux - how to make sure that java process will start using hugepages

I'm running java server on Red Hat Enterprise Linux Server release 5.9. Recently I started to use HugePages as it has some advantages I would like to use. System was configured correctly (as many ...
5
votes
2answers
3k views

Why do hard links seem to take the same space as the originals?

Thanks to some good Q&A around here and this page, I now understand links. I see hard links refer the same inode by a different name, and copies are different "nodes, with different names. Plus ...
2
votes
2answers
4k views

How to generate signal interrupt on a file descriptor in Linux?

How can I generate a signal interrupt on a file descriptor in Linux? Motivation is to generate a interrupt in userland as we have in microcontrollers. I'll have file descriptor for I/O, and want to ...
0
votes
1answer
355 views

start up Java GUI app on start up after login Linux mint

I want to start Java GUI app on start up. Java app is server and is GUI and I want to start GUI on start up after login how to do this? Any ideas?
2
votes
2answers
1k views

make permanent virtual interface?

I want to have two IPs sharing the same interface and it's just working fine by creating a virtual interface using the following command (eth0 is my original interface): ifconfig eth0:0 <someip>...
2
votes
4answers
22k views

Copying files from one machine to another without asking for password

I am currently using this command. I am on another machine (ip1) scp file.txt root@ip2:/home/praveen/test.c /home/praveen The command will prompt for password. I use it in some shell scripts, and ...
2
votes
2answers
790 views

Does sync command remove the dirty cache in the memory?

I am aware that sync command flushes the dirty cache into disk. I have run free command first, then sync, and then free again. The result of latter free command shows more free memory available than ...
2
votes
3answers
42k views

Method to check connectivity to other server

I want to check connectivity between 2 servers (i.e. if ssh will succeed). The main idea is to check the shortest way between server-a and server-b using a list of middle servers (for example if I'm ...
6
votes
1answer
5k views

I need to RDP to a server through a reverse tunnel

I have a windows PC that is on network A and a windows PC on network B. Also in network B I have several Linux servers. From the PC on network A, I can ssh to any server on network B. I cannot, ...
2
votes
2answers
1k views

A single key on keyboard produces extra keypresses for each simultaneously pressed key

I recently acquired MK-85 mechanical USB keyboard from QPAD. The keyboard works perfect on Windows. It works perfect in Syslinux. It works almost perfect on Linux. The only issue on Linux is that a ...
0
votes
1answer
129 views

Has the launcher security issue in KDE and Gnome been fixed?

One of the first things I heard about Linux is that it doesn't get any kind of malware. Now, I see it can get malware through WINE and e-mail (although I don't even open attachments or follow links ...
6
votes
4answers
8k views

Capture output of a bash command, parse it and store into different bash variables

Explanation: I have a small bash script which simply runs any Linux command (e.g. say ifconfig) The typical output of ifconfig is something like this: eth0 Link encap:Ethernet HWaddr 30:F7:0D:...
0
votes
3answers
78 views

Evaluating the output of a program as an integer

I'm trying to create a script that will evaluate the output of a command line, and then print if it's larger than 200. The program /exc/list will count the number of "stories" I have in a directory ...
1
vote
2answers
1k views

tkdiff error on Linux Redhat 5.5

I installed tkdiff as root, and it runs fine under that user, but when I switch to a local user I get the error: Application initialization failed: Can't find a usable init.tcl in the following ...
1
vote
1answer
325 views

Overcoming data word length limitation of usbmon

When capturing USB traffic with usbmon, I sometimes see the following: ffff8801ed3703c0 2599784347 S Bo:1:008:2 -115 74 = 24484880 087ffa7f dd7ffc08 d87fec7e d3000080 5e80a30c d1d43300 00803c9b The ...
8
votes
3answers
3k views

Is there a convenient small Unix virtual machine I can install as an Android app?

Ubuntu for Android seems to be missing in action. I'm travelling tomorrow and I need to take a basic Linux machine with me. I'd rather just take my tablet than a laptop. So is there a reasonable ...
5
votes
1answer
21k views

Command to transpose (swap rows and columns of) a text file [duplicate]

Is there currently a generic command that will "pivot" input. e.g. #labeled.file name: bob title: code monkey name: joe title: pointy haired is converted to: name title bob code monkey joe ...
0
votes
2answers
4k views

Linux fan control?

For some unknown reason, my laptop fan stays on consistently. Even when I'm using less than 2% CPU and the air coming out of the vent is seemingly cooler than the air in the room, the fan always stays ...
3
votes
1answer
902 views

Kernel module blacklist not working

I'm trying to figure out how to blacklist modules, and I'm trying it on the usb storage. Unfortunatelly it seems ot have no effect, and I get the module in even if it's not used (apparently). My ...