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

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32
votes
3answers
13k views

How can I “relink” a lot of broken symlinks?

I have a directory tree which has a bunch of symbolic links to files under /home... however, I have moved /home to /mnt/home and need a way to "relink" all of the symlinks. Does such functionality ...
25
votes
5answers
6k views

How do I send stdin to the clipboard?

Is there functionality in unix that allows for the following: echo "Some Text" | copy-to-clipboard
22
votes
10answers
3k views

Run two commands on one argument (without scripting)

How can I perform two commands on one input, without typing that input twice? For example, the stat command tells a lot about a file, but doesn't indicate its file type: stat fileName The file ...
18
votes
2answers
7k views

How to execute consecutive commands from history?

Suppose I want to execute a sequence of four commands that I have executed before. If the first one is 432 in the command-history, then I could do: $ !432; !433; !434; !435 I'm curious, is there a ...
10
votes
3answers
559 views

syntax_highlight <source_file> | lpr

Does anyone know of a simple way to produce the PostScript corresponding to a syntax-highlighted version of a source file that can be piped directly to a PostScript printer? As the wording of the ...
10
votes
4answers
22k views

Getting all files that have been modified on a specific date

Is it possible to find all php files within a certain directory that have been modified on a certain date I'm using find /var/www/html/dir/ -mtime -28 | grep '\.php' to get files modified within ...
9
votes
4answers
17k views

How to use /dev/fb0 as a console from userspace, or output text to it

So I have a Palm Pre (original P100EWW) model that I enabled developer mode on, and installed a Debian Squeeze chroot. Works great. I have plans to use this for ANYTHING (bittorrent peer, web ...
8
votes
3answers
3k views

How do you send command line apps directly to the background? [duplicate]

I already know that pressing ctrl+z stops the app, then I can send the app to background with the bg command, but that means there is a brief preiod of time that the app is stopped. How do I send the ...
7
votes
3answers
7k views

How to revert chown command?

If I run: sudo chown -R user:user / Can I revert it to what it was before I ran it?
7
votes
4answers
628 views

How can I find a file whose name includes a given string, such as “abcde”?

Within a set of directories, how do I find a file whose name includes a given string, such as "abcde"?
5
votes
5answers
2k views

xargs and vi - “Input is not from a terminal”

I have about 10 php.ini files on my system, located all over the place, and I wanted to quickly browse through them. I tried this command: locate php.ini | xargs vi But vi warns me Input is not ...
96
votes
8answers
42k views

How can I find broken symlinks

Is there a way to find all symbolic links that don't point anywere? find ./ -type l will give me all symbolic links, but makes no distinction between links that go somewhere and links that don't. ...
29
votes
3answers
31k views

SSH inside SSH fails with “stdin: is not a tty”

I'm trying to connect to machine one with ssh and then connect to another machine two with ssh, but I get this error. ssh user@computerone.com 'ssh otheruser@computertwo.com' stdin: is not a tty ...
46
votes
8answers
99k views

How do I make my pc speaker beep

Using bash, how can I make the pc speaker beep? Something like echo 'beepsound' > /dev/pcspkr would be nice.
13
votes
1answer
2k views

What protocol/standard is used by terminals?

I was wondering how the "GUI" of a command line application is communicated over a network. Most of the time, it's quite simple (plain text / input) but sometimes it's more complex (aptitude). Is it ...
14
votes
2answers
5k views

What is meant by a shell is in “vi” mode or “emacs” mode?

This question follows directly from the answer to one of my previous questions here. I am newbie to unix world and this site has helped a lot to understand some core concepts. In this case I am ...
13
votes
3answers
13k views

find n most frequent words in a file

I want to find, say, 10 most common word in a text file. Firstly, solution should be optimized for keystrokes (in other words - my time). Secondly, for the performance. Here is what I have so far to ...
19
votes
6answers
3k views

put history command onto command line without executing it

I use !n where (n) is the line number for executing a line in the history file I want executed at the command prompt which I find via history|less. But there is a command line history event I wish ...
11
votes
3answers
12k views

How can I move files by type recursively from a directory and its sub-directories to another directory?

What would be a good way to move a file type from a directory and all of its sub-directories? Like "move all *.ogg in /thisdir recursively to /somedir". I tried a couple of things; my best effort was ...
6
votes
4answers
6k views

All commands that should be used to connect to wifi in command line

I would like to switch from gnome to awesome and I would like to connect my wifi network in command line (instead of using gnome tools). So, I searched on the internet and found approximatively the ...
24
votes
3answers
5k views

How can I display syntax highlighting on a file?

Is there a variant of cat that outputs syntax-highlighted lines of code when used on a source file? An idea: maybe vi[m] or another editor can be asked to dump the syntax-highlighted contents of said ...
20
votes
7answers
4k 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 ...
20
votes
7answers
8k views

Isn't less just more?

When I do more filename and less filename, it would seem that the resulting terminals are quite similar. I can navigate and search through my files identically (j, Space, /pattern, etc.). I find it ...
13
votes
4answers
8k 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?
20
votes
6answers
23k views

Sorting files according to size recursively

how to scan a folder recursively and find the largest files in the folder, and sort them by size. I have tried using ls -R -S but it tends to list the directories as well I need to scan the folders ...
6
votes
1answer
4k 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 ...
10
votes
3answers
1k views

Lowercasing all directories under a directory

I want to lowercase every directories' name under a directory. With which commands can I do that?
9
votes
5answers
29k views

Pass the output of previous command to next as an argument

I've a command that outputs data to stdout (command1 -p=aaa -v=bbb -i=4). The output line can have the following value: rate (10%) - name: value - 10Kbps I want to grep that output in order to ...
9
votes
1answer
2k views

Searching for a command line tagging tool for mp3 and ogg that supports pictures

I am searching a command-line tagging tool that supports ogg- and mp3-tagging and allows to add a picture to the tags. Currently I use lltag but that does not support pictures. dagger is the tool I ...
8
votes
3answers
1k views

Bash: Capture / Use last (or Nth) line in stdout

Query I use Bash. When I'm looking for files, often I'll do the following: find -name stackexchange.hs And often the results will look like: /youre/the/man/now/dog/stackexchange.hs ...
5
votes
3answers
2k views

How can I expand a relative path at the command line, with tab completion?

In bash is there any way to expand a relative path into an absolute path, perhaps with tab completion? I ask because sometimes I will search for a file, find it, then vim it: cd /etc cd apache2 cd ...
7
votes
4answers
499 views

ls command operating differently depending on recipient

How does commands like ls know what its stdout is? It seems ls is operating different depending on what the target stdout is. For example if I do: ls /home/matt/tmp the result is: a.txt b.txt ...
6
votes
3answers
4k views

What's wrong with these two cron job's?

I have the following cron jobs defined. 55 8 * * 3 /usr/bin/php /home/mark/dev/processes/customClient/events.php > /home/mark/dev/processes/customClient/events-`date +%Y-%m-%d ...
5
votes
2answers
2k views

Remove all lines in file A which contain the strings in file B

I have a CSV file users.csv with a list of userNames, userIDs, and other data: username, userid, sidebar_side, sidebar_colour "John Lennon", 90123412, "left", "blue" "Paul McCartny", 30923833, ...
5
votes
4answers
2k views

How to remove URI encoding from file names?

I realise this might be quite a simple question, but I'm still quite new to the command line and only have a grasp of basic commands. I've downloaded some lecture presentations (~25 or so) from my ...
4
votes
3answers
2k views

Show lines matching a pattern and the 4 lines before each

For example, from this file: CREATE SYNONYM I801XS07 FOR I8010.I801XT07 * ERROR at line 1: ORA-00955: name is already used by an existing object CREATE SYNONYM I801XS07 FOR ...
3
votes
3answers
252 views

extract from line to line and then save to separate file

I tried my luck with grep and sed but somehow I don't manage to get it right. I have a log file which is about 8 GB in size. I need to analyze a 15 minute time period of suspicious activity. I ...
3
votes
4answers
6k 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' ...
5
votes
2answers
6k views

What does the tilde (~) mean at the end of a filename? [duplicate]

What is the file with the ~ at the end of the filename for? $ ls # aliased to add flags -rwxrwxr-x 1 durrantm 2741 May 16 09:28 strip_out_rspec_prep_cmds.sh~* drwxrwxr-x 13 durrantm 4096 May 16 ...
5
votes
2answers
695 views

Is there a way to retrieve the name of the Desktop Environment?

The title is quite exhaustive: is there a way to retrieve the desktop environment name (e.g. Gnome, Unity, XFCE, LXDE, KDE...) from the command line or using Python?
2
votes
2answers
794 views

What does the `who` command result `root :0` mean?

The return value of command who will always include root :0 in X Window pts. I guess it actually means the GNOME login. Am I right? Another question is where to get this knowledge, as I don't see it ...
165
votes
31answers
101k 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 ...
35
votes
5answers
100k views

How to stop a background process?

I have started a wget on remote machine in background using &. Suddenly it stops downloading. I want to stop its process, then start it again. How can I stop it? I haven't close its shell window. ...
37
votes
12answers
56k views

Efficiently delete large directory containing thousands of files

We have an issue with a folder becoming unwieldy with hundreds of thousands of tiny files. There are so many files that performing rm -rf returns an error and instead what we need to do is something ...
26
votes
3answers
17k views

How to Determine the Amount of RAM Slots In Use?

I forgot how many RAM modules are installed on my laptop. I do not want to unscrew it but want to look it up on the console using bash. How do I gather this information?
9
votes
10answers
2k views

Development environment for C

Looking for ideas on setting up a convenient and productive development environment for C development. I found C editing with Vim very helpful but I would like to get a wider sampling of suggestions.
40
votes
7answers
47k 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).
35
votes
9answers
64k views

How can I get a count of files in a directory using the command line?

I have a directory with a large number of files. I don't see a ls switch to provide the count. Is there some command line magic to get a count of files?
20
votes
2answers
55k views

How to display open file descriptors but not using lsof command

Hi I have read Here that lsof is not an accurate way of getting the number of File Descriptors that are currently open. He recommended to use this command instead cat /proc/sys/fs/file-nr While ...
14
votes
10answers
6k views

Console Text Editor with Windows-like keyboard shortcuts (ctrl-z, x, c, v)

Ok, I realise that I risk a religious war asking a question about text editors, but here goes. Requirements Mostly used for config file edits Text based not GUI Available for Raspian flavour of ...