The command-line is the interactive interface to your shell.

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0
votes
2answers
17 views

Add space after 8 characters then add space after every 4 characters

Here is the sample input: AbbigailAbieAbbyAbbi Using sed, I have separated them into 4 characters but seems like I got a problem because I have to separate the first 8 characters first then add ...
0
votes
0answers
7 views

cant edit anything on xampp as sudo user [on hold]

I’m new to Linux was an avid Windows user until recently trying on an old system seeing some major differences and converting, so I apologise if this question seems simple. I’m running the latest ...
8
votes
4answers
382 views

How do I remove spaces from shell variables?

I have done the following at command line: $ text="name with space" $ echo $text name with space I am trying to use tr -d ' ' to remove the spaces and have a result of: namewithspace I've tried ...
5
votes
3answers
110 views

I am trying to find a better/easier way to count alphabetic characters in a file or shell variable

I have a file containing the following text: we are going to write something 1 2 3 wc tells me I have 1 line 9 words and 38 characters. I'm looking to count the 26 letters only (a-z, no numbers or ...
1
vote
2answers
129 views

Count how many lines start with which characters

I have a file with a number of lines in a file filename. I want to count how many lines start with character 'a', with 'b' and so on in one go. What command i should execute.?
30
votes
8answers
4k views

Easy way to determine virtualization technology

I have command line access to a Linux machine which may or may not be virtualized. I want to determine what kind of virtualization technology it runs on, if any (VMWare, VirtualBox, KVM, OpenVZ, Xen, ...
0
votes
0answers
22 views

Gmail and mutt: msmtp error

Invalid SMTP URL: ssmtp://REDACTED@gmail.com@smtp.gmail.com:465/ I can use mutt to read my Gmail, but when I try to send I get the above message. When I installed mutt a screen came up for postfix ...
0
votes
0answers
13 views

How to maximize and minimize windows from the command line? [duplicate]

Is there any way to send a command to the currently focus window to minimize or maximize? I'd like to be able to control this from a script, or tool bar launch icon.
2
votes
2answers
37 views

Difference between who and whoami commands

The man page description of who command is who - show who is logged on But there exists a similar command whoami. The man page description of whoami is whoami - print effective userid Can anyone ...
3
votes
1answer
37 views

Get a list of applications that are playing sound [on hold]

I want to get a list of applications that are currently playing sound (using the sound card). I tried to search on a lot of places but did not succeed. Any method is fine (bash, Java, etc.). I want ...
14
votes
3answers
5k views

How do I find the window dimensions and position accurately including decorations?

I've been trying to figure out the size of a window for use in a small script. My current technique is using wmctrl -lG to find out the dimensions. However, the problem is this: The x and y figures ...
7
votes
3answers
4k views

How do I grep without leading whitespaces?

I'm greping through a large codebase, and leading whitespaces and tabulation seem to be quite annoying. Is there any way to get rid of it? grep -R "something" ./ E.g, instead of: foo/bar.cpp: ...
1
vote
3answers
49 views

How to display contents of mounted /boot and '/' root partitions?

How to display contents of mounted /boot and '/' root partitions of Debian on SSD drive from Linux Live CD? I know ls -1 to list directory contents, but what is exact steps to get this?
6
votes
5answers
12k views

count lines in a file

I'm sure there are many ways to do this: how can I count the number of lines in a text file? $ <cmd> file.txt 1020 lines
2
votes
2answers
607 views

How to change a firefox option on a quick way (via shortcuts, command line,..)?

In Firefox we have two options at Firefox->Preferences->Preferences->Fonts and colors->Colors menu, Use system colors and Sites can use other colors. I would like keep the first one ...
8
votes
3answers
895 views

How do I take a list and remove it from a file?

I have a long list of domain names that I need to remove from /etc/remotedomains. They're probably not in any particular order in the file. Each domain is on one line. How could I iterate through the ...
0
votes
0answers
25 views

How to modify ENV in Solaris 10 [duplicate]

I wanted to edit the contents of environment when entering this "ENV" in terminal. I googled this but so far none of the solution offered works in my end. The closes solution that i got was to edit ...
101
votes
27answers
21k views

Tracking down where disk space has gone on Linux?

When administering Linux systems I often find myself struggling to track down the culprit after a partition goes full. I normally use du / | sort -nr but on a large filesystem this takes a long time ...
4
votes
3answers
371 views

Switching among cli and vim and other files workflow

I saw some kind of workflow in vim: Vim had a file open. Then some combination of keys made vim disappear and the user was in the command line working in cli mode, then opened another file and then ...
6
votes
1answer
179 views

Echo difference between Ubuntu and Red Hat

I have mostly been experimenting with Ubuntu but recently was using a Red Hat Enterprise system and was surprised at a difference I found setting and displaying environment variables. In Ubuntu I ...
-3
votes
0answers
58 views

Create my own shell? [closed]

i need to create a shell in C using fork() and execv() that prompts the user to enter a command followed by a space and an argument. It should then exit as soon as the user enters exit command
0
votes
1answer
293 views

How to get sound intensity of an audio input through terminal?

I want to know the intensity of the sound being heard by an audio in source like a mic or Line-in through Command line. Kinda like the progressbar under the mouse but in CLI. audiointensity mic0 10 ...
1
vote
1answer
19 views

how to recall last argument in bash with vi setting

I use set -o vi setting in bash. The shorcut Alt+. (recalling last argument of previous command) here doesn't work as in emacs mode, so what is the equivalent for vi?
1
vote
2answers
51 views

How to identify user and server with short commands?

I've been teaching my students the basics of the Unix OS (and Linux) for 4 weeks now. I want to give them a home assignment next. It's the first one so the questions and tasks won't be hard. My only ...
0
votes
0answers
26 views

How to get mpd to recognize music library?

I have arch running on my desktop and I'm trying to play music with mpd using ncmpcpp. They are both up and running, but the problem is when I open ncmpcpp it doesn't show my music. I copied the music ...
13
votes
3answers
5k views

Break a large file into smaller pieces

How do I break a large, +4GB file into smaller files of about 500MB each. And how do I re-assemble them again to get the original file?
0
votes
1answer
23 views

How to determine Apache user from the command-line?

There is a question about the group, but I couldn't find any question/answer for getting the Apache user. Therefore how to determine Apache user from the command-line?
1
vote
2answers
44 views

Print UTF-8 file with command line tools

I want to print a file using a command like cat filename > /dev/lp0 where the file contains characters like ùàç encoded in UTF-8. Is this is possible or do I need to use CUPS? I'm using an ...
1
vote
1answer
767 views

How to access u boot environment from linux?

How can I access and change the u-Boot env variables in linux. Using the u-boot/tools/env directory in u boot directory: u-boot$ make env Which created the executable file fw_printenv. I copied ...
3
votes
3answers
189 views

Method for storing/remembering one liner commands

Often when configuring and adjusting unix-based systems I use a lot of one-line commands that are difficult to remember. For example, to determine what version of ntp (the time server) is running, you ...
1
vote
2answers
34 views

Outputting common lines from 2 files and uncommon lines from both the files in one output file

I have 2 text files. Lets name them file1.txt and file2.txt file1.txt is as follows chr10 181144 225933 chr10 181243 225933 chr10 181500 225933 chr10 226069 255828 chr10 255989 267134 ...
5
votes
7answers
644 views

What is the easiest way to add a string on the beginning of every line of the file from the command line?

I am looking for a way to add some string to the beginning of every line (same string for every line). Not something customizable but rather something that will be easy to remember and available on ...
3
votes
2answers
408 views

Jingle CLI client / Jitsi replacement / VOIP

I am looking for a Jingle client for the command line. Currently, I use Jitsi, but my dreams of not needing the GUI for more than just web-browsing are not realized due to my reliance on this ...
0
votes
1answer
656 views

Proper escaping of double quotations for curl post data?

I'm trying to test out a server, by sending it JSON data and reading the response. I need to POST data like {"item":"value with spaces"} but when I use curl I find that it sends the backslashes as ...
5
votes
3answers
1k views

Easy way to paste command line output to paste bin services?

Are there any command line tools on Linux that allow you to post output from commands or text files directly to a sharing service such as pastebin.com?
3
votes
9answers
2k views

How to generate a year-quarter date from the command line?

I'm interested in outputting a representation of the current year-quarter, as well as the year-quarter for the previous month. If today is 2012 January 1st, I'd like to get 2012q1 and 2011q4 as ...
44
votes
5answers
2k views

cd by just typing the directory's name?

I either had this somewhere 20 years ago or I dreamed about it. Basically: If if type blobblob I get blobblob: command not found Fair enough. I would like it so that when my shell gets those ...
1
vote
2answers
53 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 ...
2
votes
0answers
21 views

Close All Piped Commands if one close

I'm running at least 3 commands (with progs) using pipes. For example program1 bla bla | program2 blabla | program3 bla bla Is possible to close all programX PIDS automatically if at least one ...
1
vote
2answers
618 views

What is the difference between the whatis and apropos commands?

CentOS 6.3 / RHEL 6.3 Can someone please explain the difference between the whatis command and the apropos command? I noticed that both appear to be installed by default and I'm not sure what the ...
35
votes
3answers
41k views

ssh-add complains: Could not open a connection to your authentication agent

I've been trying to get ssh-add working on a RaspberryPi running Raspbian. I can start ssh-agent, when I do it gives the following output into the terminal: ...
1
vote
1answer
39 views

Is autocompletion for applications done by shell?

When I type evince, and then hit tab, the bash shell will list all files that can be opened by evince, which seems to be based on the ext part of the filename. Is this done by shell or the ...
2
votes
2answers
34 views

Use awk to find first occurrence

I have a log file that gets updated when my script runs. The script will insert "Start of script" text when it starts and "End of script" text when it finishes running. I am trying to capture the ...
5
votes
7answers
634 views

Linux command line. Move all files and directories in directory, except some files and directories

I have a folder A which has files and directories, I want to move all those files and directories to another folder B, except file, file2, directory, and directory2. How can this be done?
0
votes
0answers
21 views

What does !$ mean exactly? [duplicate]

echo !$ outputs different strings depending on my previous command line call. For example: mrdumbdumb-redhat:~ mrdumbdumb$ ls mrdumbdumb-redhat:~ mrdumbdumb$ echo !$ echo ls ls ...
1
vote
1answer
567 views

How to get byobu to start at startup with a command executed, as root?

I want when the computer start, a byobu session is started and a command executed in the first window (windows 0), without requiring any user intervention. It is very important that this doesn't ...
2
votes
4answers
140 views

How to display the number of lines, words and characters in separate lines?

I want to display the number of lines, words and characters, in a file, in separate lines? I don't know anymore than using wc filename for this.
4
votes
4answers
3k views

How to use ifconfig to show active interface only

By default ifconfig will show me all available interfaces , but what if I just want to display active ones? Like, en0 only in below. en0: ...
3
votes
2answers
101 views

get result text from CLI command

I'm writing a bash script and I need to capture the text resulting from the output of the rsync command, for instance, the following command: rsync -av "$FOLDER1" "$FOLDER2" prints: ... sent ...
7
votes
1answer
347 views

Is there a way to make perl -i not clobber symlinks?

A friend of mine points out that if you do: perl -pi.bak -e 's/foo/bar/' somefile when "somefile" is actually a symlink, perl does just what the docs say it will do: It does this by renaming ...