One or a set of directives issued in the *nix environment to get information, change the state of something or to execute something. In other words: To gain an objective.

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1answer
21 views

Snapshotting a Linux container in Debian

I know that the command $ lxc-snapshot exists somewhere, but it seems that it's not available on Debian? Forgive my Linux ignorance - but how do I get a hold of this capability? Is there an ...
4
votes
1answer
488 views

Which 2-letter POSIX command is different from all the others?

I was interviewed for an internship and I got the same question as this one: http://www.glassdoor.com/Interview/Which-2-letter-POSIX-command-is-different-from-all-the-others-QTN_498236.htm The ...
12
votes
5answers
13k views

Delete 100 lines from vi editor using single command

I am using Ubuntu and trying to delete all 100 lines from vi editor but I got interview question of doing this in one command.
0
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0answers
23 views

Is it logical to give root execution to some commands executed by a normal user? [on hold]

Given a C/C++ program that uses some system calls or commands, say for example sockets. In this question the solution gives root access to a normal user to run a specific one executable, which means ...
0
votes
1answer
10 views

Extract audio from video in Thunar custom actions

Thunar custom actions can be used to convert media files by adding a simple command like avconv -i %f %f.mp3 I would like a command to extract aac sound from mp4 and flv files with a Thunar custom ...
0
votes
1answer
41 views

Command not working anymore in Thunar custom actions

I used to create a Thunar custom action as presented here in order to extract audio without transcoding from selected (multiple) video files . The command to be added in Thunar custom actions list ...
1
vote
0answers
37 views

Limit transfer speed rate by Iptables Rule

I have D-Link Router DSL-2730U that support iptables version 1.4.0 and i want to know if that possible that i can limit a PC transfer speed rate (upload & download) by PC MAC Address using ...
0
votes
1answer
42 views

linux + top command

I run the top command on my linux machine and I see that vim command take like 99.5% CPU PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND ...
1
vote
3answers
79 views

Execute command in another terminal and closing it without killing command

For closing terminal without killing script/command we use & operator at last while calling command. Like: gedit & Here I used gedit as an example command Same thing I want to do on ...
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votes
0answers
16 views

I want to open a window that has to run a command automatically and should not close and should take next commands [duplicate]

Am trying to open a window from command "xterm -e "" &" but the window is closing after the command execution, after that i tried with "xterm -hold -e "" &", this time window is not getting ...
1
vote
1answer
17 views

why jobs doesn't list commands from script

I have a script that runs some programs in the background, but after running it, they are not listed by the command 'jobs'. Why is this? (./m_prog -t m_prog1 m_config) & (./m_prog -t m_prog2 ...
1
vote
1answer
58 views

What does this `xhost …` command do?

Please help me understand this line of command: xhost +SI:localuser:lightdm in reference to the answer in this post and also suggest if there's a better way and why that's needed. I couldn't make ...
2
votes
0answers
54 views

fork and wait - Unix v6 [migrated]

Here is the last part I do not understand in the source code of old unix v6 command if. Source: http://v6shell.org/history/if.c, with Syntax-Highlighting: http://pastebin.com/bj0Hvfrw if(eq(a, "{")) ...
1
vote
1answer
62 views

How to permanently enable scl CentOS 6.4?

I installed a newer version of devtoolset (1.1) and was wondering how I would go about permanently setting these to be default. Right now, when I ssh into my server running CentOS, I have to run this ...
-4
votes
1answer
38 views

What is “jobs” commmand in Redhat Linux [closed]

What is jobs command in Linux and how to use it? Please give some example.
0
votes
0answers
23 views

Is there a large performance difference between find and find2perl

Is there a performance difference between find and find2perl? I work for a hosting company and I was told that our admins prefer us to use find2perl over find. Supposedly this is because find is ...
1
vote
2answers
49 views

Read Command : How to verify user has typed something

I am a beginner in Bash so please bear with me. I'm trying to create an if else statement to verify that the user has entered something. If they have it should run through the commands, and if not i ...
5
votes
2answers
53 views

Merging/Combining 2 text files according to numeric field

I have 2 text files file_1: 14595|Age 35|Salary xx|Position ax|2013|Info 1|Info 2|Info 3|Info 4|Info 5 14649|Age 30|Salary xx|Position az|2015|Info 1|Info 2|Info 3|Info 4|Info 5 file_2: ...
8
votes
2answers
449 views

Finding a file type assuming wrong extension

I have an image archive I keep up. Sometimes, the sites I pull them from reformat the file while keeping the extension the same, most often making PNG images into JPG's that are still named ".png". ...
0
votes
1answer
23 views

Linux bash commands in android 4.1.2?

Is there a way to run linux bash commands in android (particularly 4.1.2 rooted or not rooted)? Will it void the warranty from phone manufacturers?
1
vote
3answers
85 views

What does “>” do vs “>>”? [duplicate]

I am currently doing preparation for my GCSE computing controlled assessment on Linux. I type ls > list and ls >> list into the command line, but it does not do anything. I have googled it ...
30
votes
3answers
8k views

How to stop the find command after first match?

Is there a way to force the find command to stop right after finding the first match?
5
votes
3answers
4k views

Why doesn't ln -s tell that it fails when creating a symlink to an existing symlinked directory?

When running (on linux different ubuntu variations): >ln -s dir_1 symlink_dir >ln -s dir_2 symlink_dir It fails without telling that it fails. But if you do the same thing on a file instead ...
26
votes
20answers
6k views

How do I print pi (3.14159)? [closed]

What command could print pi for me? I want to specify how many digits it prints, I couldn't find anything online. I just want to be able to print pi.
1
vote
2answers
76 views

The command 'cp' can only used on block device?

According to my last question I think we can't use 'cp' to copy file to the tape device or device like '/dev/lp0'.But I still don't understand why. To make this question simple enough,just tell me if ...
1
vote
1answer
251 views

find - exec rm vs -delete

I'm trying to understand the difference between these two commands: sudo find / -name .DS_Store -delete and sudo find / -name ".DS_Store" -exec rm {} \; I noticed that the execmethod is ...
0
votes
1answer
32 views

What is the command to check what version of Java ME I have installed?

I have Debian 6 installed on a device and want to check what version of Java ME I have installed. I tried java -version, but I get -sh: java: not found. What command should I use?
0
votes
0answers
30 views

How do I force a command to be run on local login?

I was wondering how do I force a command on login of a linux system? (debian 7). This is for a 2FA authentication command. I am asking for a local login.. not ssh.
1
vote
1answer
72 views

Get two values from command output in a bash script

I have a bashscript, which executes a command and calculates a pair of values, which output can look like this. a,b (10.0000000000, 10.0000000000) -> volt (2088133.7088034691, -222653.3238934391) ...
2
votes
1answer
67 views

Convert all non-JPG images to JPGs

What command can I use to convert all images in a folder which are not JPGs (PNG and BMP primarily) to JPG? I'd also like the conversion quality to be 100%. And I'd like the converted images to ...
1
vote
1answer
36 views

What is the name of the app displaying custom text in fullscreen size?

I have seen years ago a very handy application: the command displayed it's first argument enlarged to fit the whole screen. For example... thiscommand AA ...then you could see two very big A ...
1
vote
1answer
69 views

Using alot MUA with nottoomuch-addresses

I try to use the MUA alot to work with the nottoomuch-addresses.sh script for autocompletion of addresses within alot like described in: ...
2
votes
2answers
34 views

Is there a `--paranoid` type flag for common, potentially irreversible commands?

I'm not aware of any standard flag that is implemented. There are some git commands that let you specify a -n parameter that will show you what the command is going to do, but doesn't actually do it. ...
1
vote
1answer
32 views

Checking permission for files

Is there any way to check/find files and directories that only I created and check their permission?
-2
votes
1answer
65 views

Sorting by size

When I run ls | sort -S I get sort : option requires an argument -- ´S´ Why I cant sort the list of my files with the sort option by size? I know that I can use only the ls command alone. ...
2
votes
2answers
90 views

What filesystem mount point am I currently working on?

I would like to know in what filesystem mount point I am currently on, similarly to using pwd to know what directory I am in. I know you can use df . (or df $(pwd) or many variants), but I find it ...
1
vote
3answers
36 views

Command that passes its input through to output AND performs command?

I'm trying to use the quote program to make a little shell script that'll keep updating the stock prices every second. quote has to access the Internet and therefore has a small delay when it runs. I ...
1
vote
2answers
67 views

Find average CPU, vMem, sMem usage on 1, 5, and 15min

I am trying to find at time T the average CPU usage on 1, 5, and 15min, just like what you get from /proc/loadavg Same thing for virtual memory, and swap memory. I would be fine with a python ...
0
votes
2answers
191 views

What are the meanings of different Unix commands? [closed]

I am running Ubuntu 14.04 on my machine. I am new to Linux and feeling lost when I see different command line commands (or what exactly are they called?) like sudo, apt-get, mkdir, -R, -n etc. while ...
1
vote
2answers
59 views

Replace text/string with new line

I have had a requirement where I need to move data to a new line based on a text: Input :61: 456 B66666 :61: 878 N78777 :61: 534533534 BNNN Output :61: 456 B66666 :61: 878 N78777 :61: 534533534 BNNN ...
0
votes
4answers
61 views

How to save in a variable the convert from decimal to binary without use an echo

I've been trying to save in a variable the value of the convert of a number from decimal to binary, like this: num1=10 echo "obase=2;$num1" | bc | tee -a register.txt but I don't want to show it ...
3
votes
2answers
241 views

How to use getopt in bash command line with only long options?

There is a getopt command in bash command line. getopt can used with short options (such as getopt -o axby "$@"), and can be used with both short and long options (such as getopt -o axby -l long-key ...
1
vote
1answer
41 views

Execute commands when specific user and ip login to ssh

How can I execute a few commands when a specific user with a specific IP logs on via ssh?
6
votes
3answers
3k views

Difference between 'ifconfig' and 'ip' commands

I read some articles/tutorials on 'ifconfig' command, most of them included a common statement - "ifconfig is deprecated by ip command" and suggested to learn ip command. But none of them ...
4
votes
2answers
4k views

How to see the total progress while copying the files

We know that if we give --progress parameter to rsync it will show the progress of files copied. But issue is that is shows the progress for each single file not total or overall progress. So how to ...
-8
votes
2answers
53 views

How to create my arbitary output? [closed]

How can I write a shell script that give me following output: Today is: Thursday, November 05, 2014 The IP for localhost.localdomain is: 192.168.141.140
1
vote
1answer
129 views

Why is variable assignment preceding command ignored? [duplicate]

The bash 4.1 manpage states (emphasis added)... Simple Commands A simple command is a sequence of optional variable assignments followed by blank-separated words and redirections, and ...
0
votes
1answer
60 views
6
votes
2answers
443 views

what is the meaning of this sed command: `;/@/{h;s/test/next/g;x;G}`?

sed -e 's/72;/72, next_val = 0x11111111;/;/@/{h;s/test/next/g;x;G}' fmt_vuln.c > fmt_vuln2.c could you tell me about what is the meaning of ;/@/{h;s/test/next/g;x;G}?
5
votes
1answer
411 views

What exactly are commands? How to identify? [duplicate]

I want to know what exactly are Linux commands? & how to identify and locate them? (Say Introduce the "commands") In other words what are different kind/type/category of commands? How to identify ...