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

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42
votes
7answers
121k views

Run a command without making me wait

On the CLI, sometimes a command I type takes a while to complete, and sometimes I know when that's about to happen. I'm a bit confused on "backgrounding" and such in Linux. What is the most common ...
3
votes
1answer
492 views

How to check corrupt and duplicated fonts on Linux?

I need to find software that can detect duplicate fonts out of a folder, and be able to tell if a font file is corrupted. Needs to be command line so I can script it for situations, although if you ...
0
votes
4answers
28k views

Opening Firefox from terminal [duplicate]

When I type firefox in terminal, it starts Firefox but the terminal "hangs". What is happening behind the scenes? Can I open Firefox from terminal and keep on using the same terminal tab for other ...
13
votes
2answers
7k views

what is `env <command>` doing?

What is the command env ls -al doing? I had a Linux test and there was question: "How to run command directly, but not its alias?" I knew that there exists solution like prefixing command with some ...
6
votes
2answers
15k views

Get common name (CN) from SSL certificate?

I have a SSL CRT file in PEM format. Is there a way that I can extract the common name (CN) from the certificate from the command line?
3
votes
1answer
229 views

bash: color matching string [duplicate]

I am looking for a command which would color a matching string in text. I.e. I am looking for functionality similar to what grep does, but I want to see the complete text not only the matching lines ...
3
votes
2answers
1k views

How do I create a dialog with multiple text fields using zenity?

I want to crate a GUI for some command line programs and I need to get info from multiple text fields e.g. 'Username', 'Password' and a checkbox 'Sign automatically?'. I need to set particular ...
32
votes
7answers
8k views

How do I get a websites title using command line?

I want a command line program that prints the title of a website. For e.g.: Alan:~ titlefetcher http://www.youtube.com/watch?v=Dd7dQh8u4Hc should give: Why Are Bad Words Bad? You give it the ...
9
votes
4answers
34k 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: ...
2
votes
1answer
2k views

Unable to install SciPy

I need to use the module skimage, which calls the module SciPy (I need to find contours) import numpy from sys import argv from PIL import Image from skimage import measure # Inicialization ...
3
votes
4answers
684 views

How do you find what keys the “erase” and “line-kill” characters are in Ubuntu?

I'm new to Unix and have bought today a copy of "The Unix Programming Environment". I'm trying out the stuff from the book. But some of them are not working as expected like : To kill a line and ...
5
votes
2answers
2k views

Show tail of files in a directory?

I have a directory that is too huge to browse by any means. Grepping returns argument lists too long, WINSCP crashes when trying to open the directory. Is there a way I can view just the last 200 ...
3
votes
1answer
336 views

Getting size of directories and exclude some folders

I have an directory structure like this: application1 application1_edit application2 application2_edit Is there any way to get the total size for every folder (including sub-directories) and ...
2
votes
1answer
1k views

Can I split a avi file into 2 valid (watchable) files with only standard unix commands?

The question is self explanatory. I have a very big movie file, I want to split it in 2. How can I do this?
5
votes
1answer
2k views

List a directory, including subdirectories, with file count and cumulative size

Is there a way to list out the content of a directory including subdirectories with a file count and cumulative size? I would like to see: Number of directories Number of sub directories number of ...
0
votes
2answers
385 views

Regex and patterns on a ksh command line

I'm wondering what's the difference between using * and .* in a regex string. I guess, * stands for "0 to n characters" but I don't see what .* stands for. For example, what is the difference ...
3
votes
4answers
9k views

get age of given file

How can I get the age of a given file in, at least, days? I'm well aware of ls -lh and similar commands. I want something that will work sort of like this: getfage <FILE> # prints out '12d' ...
20
votes
2answers
2k views

Create a test file with lots of zero bytes

I know how to create an empty file: touch /var/tmp/nullbytes but how can I create a 1MB file that only contains nullbytes on the commandline with bash?
-2
votes
2answers
360 views

How to handle binary data in Linux [closed]

One of the my servers gives me data with Content-Type: application/binary, i.e data that I am getting looks like some alien data. Now I need to convert that data into plain data, but I am not aware ...
0
votes
1answer
355 views

Current IP address as visible from the internet? [duplicate]

I know I can get the locally assigned IP address of my current machine by the local router like so: ifconfig However, I want to know what my IP address is as visible from the outside world. Or, in ...
7
votes
1answer
4k views

Get the current volume level in OS X Terminal CLI?

I would like to check the current volume level from the CLI on my Mac. I know I can set it like this: osascript -e 'set volume <N>' But that doesn't seem to work when trying to get the ...
3
votes
1answer
146 views

Navigating the CLI: Go back N words

I'm a Vim user, so I'm learning Emacs commands for use in the Bash CLI. I know that on my systems I can use Vim-keybindings in Bash but I'd like to learn how to use it effectively in its default ...
3
votes
2answers
7k views

What is “Exit 2” from finished background job status?

I have an exercise to put in a file some data (*conf from some directories) and need to do this in background. I did it and I am wondering what is the meaning of output messages: [A@localhost tests]$ ...
4
votes
3answers
10k views

How to execute same command “X” multiple times with a time delay of some number of seconds? [duplicate]

I know how to execute multiple commands at same time but now what I need is to run the same command multiple times with some time delay between the command execution. Requirements I don't want to ...
8
votes
6answers
12k views

How to remove blank lines from a file in shell?

I want to remove all empty lines from a file. Even if the line contains spaces or tabs it should also be removed.
1
vote
1answer
209 views

Make terminal print name of parent process OSX [closed]

Slightly above n00b, but not by much. I made an alias to search for and display all of the processes associated with a specific user account that seem to auto initiate every time I log in, which are ...
1
vote
2answers
218 views

Using globbing/wildcards when Opening Files from Terminal

I have a folder A. Inside the folder, there are some files a,b,c,d and there is a subfolder, B, containing files e,f,g. Suppose I want to open files a,b,c,d: then I just type xdg-open *. However, ...
10
votes
3answers
12k views

Generate File of a certain size?

I'd like to generate a file with the name example.file. I could use touch example.file but I want the file to be exactly 24MB in size. I already checked the manpage of touch, but there is no ...
2
votes
2answers
93 views

Proper escape sequence for a non-standard file name [duplicate]

I'm trying to remove a file I made by mistake using --exclude with tar. I ended up making a tar file named --exclude=*.tar Now I want to delete it but I'd like to rename it first. How do I escape it ...
2
votes
1answer
1k views

Command(s) to install tempfile on CentOS 6.4

I'm looking to install the package for tempfile but am not finding it? possibly use mktemp but I'm not sure if there is a difference in behaviour besides a dot notation in the temp name? $ tempfile # ...
0
votes
1answer
272 views

what does the following command do?

what does the following command do? I have tried to study the linux command but I could not find out what this command does. here is the command: touch finger ; finger touch
5
votes
3answers
183 views

Robustly segmenting a csv file containing noisy data

Say I have a csv file with these columns: timestamp,cpu,memory An example of the shape of the actual data would be this chart: Having the data visualized in this way, it's easy for the human eye ...
-1
votes
2answers
514 views

How to install Okular under SUSE (on a server)?

I would like to install the pdf viewer Okular on a SUSE Linux Enterprise Server 11. I am familiar with apt under Ubuntu, but on SUSE, I only found rpm to install .rpm files. I am wondering how Okular ...
2
votes
1answer
131 views

What is the meaning of the .: in this linux statement?

Somebody helped me run a java program with the following (working) line of code. The zookeeper-3.4.5.jar exists in the working directory. What it is the meaning of the .: syntax here? Does that just ...
4
votes
1answer
348 views

Can I pipe lpt port over tcp?

I'd like to pipe data in and out to a lpt (parallel IEEE 1284) port on another machine, to remotely use a device. Can it be done in a common unix-y system? I have ubuntu 12.04. :) I was thinking ...
3
votes
4answers
518 views

Is there a difference between ./script and bash script? [duplicate]

Given a shell script file that begins as #!/bin/bash # (bash script here), and has been chmod +xed, is there any difference in running ./script and bash script from the command-line?
0
votes
1answer
912 views

Script for running sequential job

I started recently to learn using Linux. I want to write a script in bash shell to run a serial job on a cluster. I have been searching for hints and instructions on how to write such a script. I ...
2
votes
4answers
4k views

Count tabs per line in text file with utils

I have a tab-tabulated file. I would like to check if every line has the same number of tabs. For first step, I'd like to print the number of tabs for each individual line. I've tried grep -o '\t' ...
0
votes
2answers
262 views

Using Pipeline to Direct Files to Program that Opens Them

I have a Music folder, in which I have some music tracks, which aren't organized too well. Thus, if I want to find a particular track, I usually type: ls Music | grep <keyword>, where ...
3
votes
2answers
938 views

How can I uninstall packages from the command line on Ubuntu?

I am wondering how one would uninstall software from the command line/terminal. What commands would I use?
18
votes
2answers
85k views

Sending messages to another user

Is there any command to send messages through the Linux shell to other people on the same network? I'm using write user and then write the message itself. But there's any command that doesn't show my ...
9
votes
2answers
19k views

How to write text into the first line of a file?

I've been looking around sed command to add text into a file in a specific line. This works adding text after line 1: sed '1 a\ But I want to add it before line 1. It would be: sed '0 a\ but I ...
5
votes
1answer
25k views

What does 2>&1 in this command mean? [duplicate]

I understand that this command attempts to write to nowhere or a null device but what does 2>&1 mean here? wget -q -O - http://yourwebsite.com/wp-cron.php?doing_wp_cron > /dev/null ...
2
votes
2answers
153 views

Run last line of error message as a command

If you were trying to run a package that is not installed, for example: me ~: gparted The program 'gparted' is currently not installed. You can install it by typing: sudo apt-get install gparted ...
0
votes
1answer
344 views

How to start “Shape collage” application from terminal

I just installed application "shape collage" on my Archlinux, but I don't know how to start it via the terminal. Command shape-collage doesn't seem to work.
2
votes
2answers
116 views

What is the meaning of this error: example: Is a directory

I'm trying out fuse with this tutorial. When I try to run the example using the command below, I get this error: memsql@memsql-virtual-machine:~$ ~/fuse-2.9.3/example> ./hello /tmp/fuse -d bash: ...
1
vote
2answers
253 views

How to use `ls` to group and show only a first word of directory name?

I want to define a new ls command to do something like this The first when i use ordinary ls command: $ls undergrade.AI undergrade.KDD undergrade.AI2 undergrade.micro ...
3
votes
0answers
390 views

Xorg Setting checking from Command Line

How do I determined, whether Xorg is using Xinerama, DDC and Reduced Blanking ?? Just adding few options in Xorg.conf is sufficient ? If I have to check from command-line, then how can I check ...
1
vote
3answers
118 views

Terminal: Use different command on previous file

I know that there is the !! command to reuse the previous command. How would one reuse the file or directory specified in the previous command but use a different command on it? Example: I want to ...
5
votes
2answers
831 views

Why does Bash history not record this command?

The command printf "#!/bin/bash\n" > t generates an error(bash: !/bin/bash\n": event not found), but hitting the up key does not recall the command so that I can modify it. Why is that? (What I ...