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

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4
votes
1answer
108 views

What is this construct in bash? mycommand(){dosomething;}

I actually found following one-liner on commandfu.com: cmdfu(){ curl "http://www.commandlinefu.com/commands/matching/$@/$(echo -n $@ | openssl base64)/plaintext"; } I have not come across a similar ...
17
votes
4answers
20k views

Understanding the exclamation mark (!) in bash

I used history | less to get the lines of previous commands and from the numbers on the left hand side I found the line I wanted repeated (eg. 22) and did !22 at the command prompt and it ...
3
votes
2answers
395 views

I need help with a cronjob to watch for runaway processes and kill them

I have an interesting situation, I have a runaway ruby process - I know exactly how I trigger it. Point is, it got me thinking about runaway processes (CPU usage or memory usage). How would one ...
6
votes
3answers
754 views

Deleting lots of files

I accidentally created 8 million files and every time I'm trying to delete them the server almost dies because of the rm process eating all disk IO (the server is remote without console). Should ...
27
votes
3answers
31k views
3
votes
2answers
937 views

Difference between wget versions

I have problem with wget behavior for 1.10 and later versions. I am using wget to download a report from my app. version 1.10.2: >wget-1.10.2.exe --http-user=trader --http-passwd=trader ...
1
vote
1answer
109 views

How can I create a file that just contains a binary number?

I would like to create a file that just contains a binary number. I think that touch can be used to create an empty file, but is there any way I can fill it with a binary number e.g. 10 (ten)? And how ...
2
votes
1answer
966 views

How can I check the Base64 value for an integer?

I would like to check the Base64 value for an integer. There is a base64 linux command but I don't understand how I can apply it on integers. I have tried with base64 10 but then I get the error ...
5
votes
4answers
224 views

How could I simplify this command to only use awk?

awk '/user/ {print $1 }' /etc/userdomains | sed 's/://' the format of /etc/userdomains is domain.tld: user otherdomain.tld: otheruser
8
votes
2answers
843 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 ...
9
votes
3answers
11k views

Grabbing the first [x] characters for a string from a pipe

If I have really long output from a command (single line) but I know I only want the first [x] (let's say 8) characters of the output, what's the easiest way to get that? There aren't any delimiters.
3
votes
1answer
6k views

How to increase the TTY fontsize?

I have a fedora machine, I am used to working on CLI since I had CRT monitor, after switching to TFT - the experience is not the same I had with CRT, the font is smaller now. How to change it?
8
votes
6answers
6k views

Modifying PDF files

I need to do some basic editing on existing PDF file. I.e. I need to: Add chapters/bookmarks Change some page numbering However I cannot find any tool - GUI or commandline - which would offer this ...
1
vote
1answer
1k views

vnc connection working with PuTTY but not with command line

I am using PuTTY to connect to a distant network to then set up x11vnc and then using ssl/sshvnc as a client. in the host name for PuTTY I have: ssh.inf.uk and port: 22 in the ssh tunnel options I ...
3
votes
6answers
592 views

How do I find a command if I don't know its name?

As a Unix beginner, I often find myself wanting to know the name of the command that achieves a particular function I'm after. How can I go about finding out the name of the command, given a ...
5
votes
1answer
904 views

How to get a persistent “history”-file even after a non-clean shutdown?

I am trying Ubuntu Server 10.10 in VirtualBox. I like that the commands I run is saved in a "history"-file that can be shown with the history command. But if I just turn off VirtualBox without the ...
3
votes
1answer
1k views

Montage together five gifs

I have five gifs all with the same number of frames and the same framerate. Is it possible to montage these together into one gif where each frame is similar to a normal montage of static images and ...
6
votes
6answers
528 views

How can I reproduce commands run on one machine on another machine?

I would like to install some software on a linux-machine that I have run in VirtualBox. Then I would like to do the same thing on a linux-VPS. I think that I can save all commands that I run using ...
11
votes
7answers
9k views

grep and tail -f?

Is it possible to do a tail -f (or similar) on a file, and grep it at the same time? I wouldn't mind other commands just looking for that kind of behavior.
1
vote
1answer
1k views

What strings should I look for in /var/log/auth.log?

I wrote a bash command to scan /var/log/auth.log for messages occurring on the current day indicating unauthorised access. Currently it just fetches messages matching BREAK-IN and unauthorized. What ...
7
votes
5answers
9k views

how do I add newlines between lines printed on the command line?

Mail logs are incredibly difficult to read... how could I ouput a blank line between each line printed on the command line. For example say, i'm grep-ing the log. That way multiple wrapped lines ...
17
votes
7answers
3k views

Command-line-friendly full-text indexing?

Is there such a thing as a full-text indexing engine, that can be queried from the command line and ideally wouldn't require using a gui at all ? I'm especially interested in indexing my ebooks and ...
10
votes
2answers
11k views

What does ^d mean in ls -l | grep ^d?

When I do ls -l | grep ^d it lists only directories in the current directory. What I'd like to know is what does the caret ^ in ^d mean?
24
votes
4answers
4k views

How to echo a bang!

I tried to create a script by echo'ing the contents into a file, instead of opening it with a editor echo -e "#!/bin/bash \n /usr/bin/command args" > .scripts/command The output: bash: ...
5
votes
1answer
463 views

How to use the ul command line utility

I wanted to answer http://unix.stackexchange.com/questions/3043/use-roff-to-underline-words with "just use ul, this command is meant specifically for underlining text", however I just can't grasp how ...
1
vote
2answers
755 views

How can I shutdown after unmounting a USB device from the command line?

Previously, I asked this question about how to suspend Linux after a set amount of time. I would like to ask a similar question. Supposing I have a USB device attached to my system (OS = Fedora 13), ...
19
votes
5answers
19k views

How do I convert an epoch timestamp to a human readable format on the cli?

How do I convert an epoch timestamp to a human readable format on the cli? I think there's a way to do it with date but the syntax eludes me (other ways welcome).
4
votes
2answers
3k views

Is there a way to empty the trash/wastebasket from the command line?

This would be great especially considering the latest version of Ubuntu is very slow when displaying directories on my PC...
12
votes
3answers
4k views

Sunrise and other astronomical data from the command line

Is there a simple open-source, command-line program that can show the sunrise and sunset times at a given date and location, and perhaps moon and planet data as well? Browsing the Debian package ...
6
votes
1answer
3k views

Show a notification across all running X displays

Using the command line, I'd like show a notification on every running X display. ( and running console ) Something like: notify-send-all 'Warning' 'Nuclear launch in 5 minutes, please evacuate' Is ...
21
votes
1answer
14k views

What is the difference between modify and change in stat command context?

The stat command's manual page says: %x Time of last access %y Time of last modification %z Time of last change I am unable to understand what is the difference between ...
20
votes
4answers
14k views

How to redirect output of wget as input to unzip?

I have to download a file from this link. The file download is a zip file which I will have to unzip in the current folder. Normally, I would download it first, then run the unzip command. $ wget ...
6
votes
2answers
2k views

Getting and setting screen size for Xorg

I would like to run a command like get-screen-resolution during a X session to get a '800x480' output. ( or whatever the actual screen size is ). Is there something available for this? Currently I ...
6
votes
1answer
487 views

Difference between references of Linux “utilities”, “commands” and “programs”

I read uses of the word "utilities" for commands/programs such as 'ls', 'chmod', 'mv', etc. Is "commands" is Linux referring to the same things as top, ps, etc., or are those something different? ...
8
votes
3answers
622 views

how to queue a command to run after another command finishes?

Sometimes I start a program that takes a very long time to finish (emerge), then realize that I should go to bed instead of waiting for it. If I know this in the first place I would run program; halt ...
2
votes
5answers
2k views

how to pass the result of `find` as a list of files?

The situation is, I have an MP3 player mpg321 that accepts a list of files as argument. I keep my music in a directory named "music", in which there are a few more directories. I just want to play all ...
42
votes
6answers
15k views

How can I move files and view the progress (e.g. with a progress bar)?

When moving large directories using mv, is there a way to view the progress (%)? The cp command on gentoo had a -g switch that showed the progress.
6
votes
3answers
1k views

Command line join of password protected wireless networks in Ubuntu, Arch Linux, or other distros?

Is there a way to join a password protected wireless network via the command line in installations of Ubuntu or Arch Linux with no desktop environment or any GUI installed? Also, could this be done ...
7
votes
2answers
3k views

How do I merge two *.srt files

Please see this question. I have just merged two avi files cd1.avi and cd1.avi into movie.avi using: avimerge -o movie.avi -i cd{1,2}.avi Problem is that I had to subtitle files linked to the ...
11
votes
3answers
14k views

How do I put a hat on 'e' (ê)?

Since I've migrated to linux a few years ago, one issue still remains. The ê character features a lot in my "moeder taal" (home language). In Windows making the character was easy, I simply had to ...
11
votes
4answers
6k views

How do I merge two *.avi files into one

I have two *.avi files: sequence1.avi sequence2.avi How do I merge these two files using a command-line or GUI?
8
votes
3answers
14k views

How do I count the number of occurrences of a word in a text file with the command line?

I have a large JSON file that is on one line, and I want to use the command line to be able to count the number of occurrences of a word in the file. How can I do that?
10
votes
3answers
6k views

copy recursively except hidden directory

How do I copy recursively like cp -rf *, but excluding hidden directories (directories starting with .) and their contents?
2
votes
1answer
264 views

How to save temp data

updated: I'd like to save a large amount data ( ~ 100MB ) from the standard input in temporary location for the duration of my bash session. Piping it to a file won't work as I have only 30MB of ...
5
votes
2answers
1k views

How to suspend and resume processes

In the bash terminal I can hit Control+Z to suspend any running process... then I can type fg to resume the process. Is it possible to suspend a process if I only have it's PID? And if so, what ...
8
votes
5answers
476 views

What's the best way to take a segment out of a text file?

What's a good way of extracting say, lines 20 -45 out of a huge text file. Non-interactively of course!
7
votes
2answers
944 views

grep - why do brackets in grep pattern remove the grep process from ps results?

Why do brackets in a grep pattern remove the grep process from ps results? $ ps -ef | grep XXXX [...] XXXX [...] grep XXXX $ ps -ef | grep [X]XXX [...] XXXX
3
votes
3answers
356 views

Quoting commands

As I've learned to use Linux over the years, I've repeatedly come across the idiom of quoting commands with a leading backtick (`) and a following single quote ('), like so: `rm -rf /tmp/foo/bar' (I ...
1
vote
3answers
929 views

Commandline gstreamer player

Is there a good, simple commandline player that uses gstreamer?
7
votes
1answer
3k views

Command-line mv exclusion list

Is there a way to mv,cp, or any file operation such that I could specify all the files I don't want affected? For example, say I have a folder with the files file1, file2, and file3, and I want to ...