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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27
votes
3answers
7k 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
3k 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 ...
25
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
46 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 ...
0
votes
1answer
45 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
13 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
23 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
46 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
54 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
31 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
64 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: ...
1
vote
2answers
30 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. ...
-3
votes
0answers
55 views

7z command for files larger than 4GB ( unzip doesn't work) [duplicate]

My unzip command doesn't work for files that are greater than 4GB. Consider my file name is unzip -p -a filename.zip, the command doesn't work since the size of the file is larger. I need to know the ...
1
vote
1answer
31 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
30 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
75 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
32 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
47 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
149 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
39 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
47 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
108 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
36 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
2k 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
3k 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 ...
-7
votes
2answers
50 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
100 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
51 views
6
votes
2answers
413 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
403 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 ...
-2
votes
1answer
160 views

Delete all mails from inbox using linux command prompt

How can I delete emails from an individual email account? e.g. how can I empty userxyz@mydomain.com? I know the following: /var/spool/mail/mydomain /var/mail/mydomain I have many inboxes some of ...
1
vote
1answer
26 views

What does the parenthesis mean in a command description like “mklost+found(8)” [duplicate]

When googling for linux commands, I often see a number in parenthesis like this: mklost+found(8) What does it mean? Is it a version number of the program, reference to some standard, or what?
11
votes
5answers
33k views

How to move all files and folders via mv command

How can I move all files and folders from one directory to another via mv command?
0
votes
0answers
26 views

want to replace a file data from another file [duplicate]

I want to replace a file data from another file Suppose file1 have data written below and file2 have some data i want to store replace file1 data from file2 from starting word // +++ CUSTOMIZATION ...
19
votes
4answers
1k views

The difference between -r and -R

It often happens that I want to apply an operation recursively. Some commands, such as grep, use a lowercase r to indicate recursion. For example grep -r foo . Other commands seem to prefer an ...
1
vote
2answers
78 views

How to kill all processes for a given user that take longer then X time

When I list processes with ps auxf I often see some that are stuck and I need to manually kill them. How can I do it with one command? Example ps result: $ ps auxf USER PID %CPU %MEM VSZ ...
1
vote
3answers
79 views

What is the concept hidden behind the term “command”?

I have been using, studying and developing for Linux for quite a few years now, and over time, I have successfully convinced a few people to join the cause, and make the switch to Linux. However, ...
2
votes
1answer
50 views

Command to print few consecutive lines from middle of a file [duplicate]

For a file containing 20 lines, lines 6-10 can be printed using following command: head -10 filename | tail -5 Can this exactly same thing be done without using 'head' and 'tail' commands ?? ...
0
votes
2answers
51 views

execute command from txt file

I have file and in this file i have this lines: ssh root@server1.com ssh root@server2.com etc.... And i have script that i like to go on every server and execute the ls command on each of this ...
2
votes
1answer
69 views

How to convert .doc to ODF with a command line?

I'd like to convert many Microsoft Word documents to ODF (the OO.org formata with a command line (because there are many of them). (I need them for reading afterwards on a device where reading OO.org ...
1
vote
0answers
33 views

Edit a command? [duplicate]

I'm using many basic commands of unix/linux. In Mac OS X Mavericks, I type cat for a file, but output was faulty. In example, content of the file named bar: foo bar Then: ...
5
votes
1answer
183 views

What does `init [2]` mean in the COMMAND column of ps?

Reading What do the brackets around processes mean? I understand that the executable name is printed. Linux ps man page: Sometimes the process args will be unavailable; when this happens, ps will ...
9
votes
6answers
1k views

How do you remember command options? [closed]

I am curious to know what trick you use to remember options for various commands? Looking up man pages all the time is time consuming and not so cool!
4
votes
5answers
98 views

unix command to print till 3rd occurence of “/” in each line

I have one file contains data as follows... /tutordashboard/manageTutorLogInStatus/?ua=TQ-AUTOCLOSE-REENTER&filterId=089089087087080&dt=1325757272 ...
2
votes
1answer
48 views

What is a command that will only show me the command syntax and options?

Is there a command which will just list all the options for a given command on one or two lines and not as long and words as man or info ?
0
votes
2answers
48 views

`cron` service and `at` command

Help to understand: is there any relation between cron and at command. Actually if I stop the cron services in SUSE by running following command: /etc/init.d/cron stop after above, if I run at ...
1
vote
3answers
158 views

What is $() in a command?

What is $() in Linux Shell Commands? For example: chmod 777 $(pwd)
85
votes
3answers
8k views

Why is “echo” so much faster than “touch”?

I'm trying to update the timestamp to the current time on all of the xml files in my directory (recursively). I'm using Mac OSX 10.8.5. On about 300,000 files, the following echo command takes 10 ...
6
votes
4answers
2k views
1
vote
3answers
201 views

How to rename file using substring of the same file name [duplicate]

I want to rename my file with its substring.Because unfortunately renamed all the files in my server. Now I want to remove suffix( .gz) of all the files including files in subdirectories also. Below ...