A shell is software that lets users interact with the operating system, usually by typing at a command-line.

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What is the difference between /etc/environment and /etc/profile?

I understand that the former is loaded prior to the latter, but what is the conceptual difference? Are there any good reasons I should set some variables in one and not in other? Except the fact that ...
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1answer
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tee for Windows?

Does Windows provide the basic tee facility for copying standard input to an arbitrary set of files and then back out to standard output? I generally download a generic tee program, but curious if ...
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269 views

How to quickly get the previous line output in a terminal without using a mouse?

Linux (e.g. Ubuntu) terminal, is there a method to get the last line? Say I am randomly typing a td command, which has not been installed on my system, so I will get a message like below. I would like ...
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Transfer current command to a detachable session (tmux/screen)

I'm currently running a backup and it now needs to be transferred to detachable one like on tmux/screen. Is there a way to do this when the command is currently running? I can send the command the ...
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Per-directory bash/zsh history log files

I find I do a lot of work on a project in a set directory. Sometimes — a few months down the track — I need to redo something on that project but I can't remember what I did. I use ...
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Run a GUI app on remote computer from SSH

I want to run a GUI application on my Ubuntu computer, but it should started by a shell script on my Debian server trought SSH. Is this possible?
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Linux command to find files changed in last n seconds.

I would like a Linux command to find files changed in last n seconds. Is there a shell script or other tool that I can run from command line interface or gui?
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Linux & Shell - Is Shell a must?

A total newbie question. Why do we need a shell in Linux? As an example when I type - find . -name xy* - I was told that the shell takes this input and calls the find command (making sure the wild ...
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Ending a process in unix instead of interrupting it

At the unix command line if i press Ctrl-C,that does not end a process but rather interrupts it and i return to the shell prompt. So,i have the following two questions: 1.Is there a way i can see the ...
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How to find out the top space-consuming directories or files?

My disk is running out of space: $ df -h Filesystem Size Used Avail Use% Mounted on ... /dev/sda7 803G 715G 48G 95% /home I'd like to go through the whole home directory and find ...
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unix - split a huge .gz file by line

I'm sure someone has had the below need, what is a quick way of splitting a huge .gz file by line? The underlying text file has 120million rows. I don't have enough disk space to gunzip the entire ...
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How do I delete a file named “-p” from bash?

How do I delete a file named -p in bash? Trying rm "-p" complains that -p is not a valid argument.
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Will a Mac help me learn Linux?

I worked with a Mac last week for the first time ever. I noticed that the shell is very similar to Linux. I normally develop on a Windows machine and tend to be a noob at all things Linux. Will a Mac ...
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Set $PS1 differently on local computer and in ssh session

I keep my home directory under version control, so that my basic configuration is easily available on any computer. My bash command prompt on my local computer is a complicated, colorful thing that ...
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3answers
72k views

Run a shell script with an html button

I want to launch a bash script when a button is pressed on a website. This is my first attempt: <button type="button" onclick="/path/to/name.sh">Click Me!</button> But no luck. Any ...
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what's the usage of -exec xargs and -print0

I think these are the common ways of passing the result of one command to the next one, as inputs. Can anyone here explain to me how these three works? or forward me to some websites/URL?
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How to shut down a computer having a particular IP address?

If we have a collection of Windows and Linux computers on a LAN, is it possible to shutdown a computer having a specific IP address, using the Linux shell? Assume that I do not have ssh or telnet ...
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605 views

How can I easily see the man page for builtin shell commands?

If I see a command in a script that I don't know and I type (for example) man pushd or man umask I see the man page for builtin commands. I know that I can do man bash and scroll to find the help for ...
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Aliases in subshell / child process

I set up aliases in /etc/profile.d/alias.sh for each login shell. But if I run script.sh, I can't use that alias. How can I set alias even for subshells or child processes ? /etc/profile.d/alias.sh ...
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863 views

Running `exec` with a Bash built-in

I defined a shell function (let's call it clock), which I want to use as a wrapper to another command, similar to the time function, e.g. clock ls -R. My shell function performs some tasks and then ...
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How do I log all UNIX shell commands submitted by all users?

Is there an elegant way to log every command submitted in all shells on a machine? This is in the context of an infrequently-used Ubuntu server, of which I am the only human user. (There are several ...
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2answers
617 views

Can I keep . and .. out of .* expansion?

I often find it annoying (or worse) when I type command .* in bash and the command applies to the parent directory and current directory. Is there some shell option or other configuration I can ...
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107 views

Is it possible to modify bash to run one command through another (say a python script)?

I was wondering if it is possible to modify bash such that when I type command --arg1 what actually happens is ~/prerun.py command --arg1 (prerun.py would handle starting command --arg1 itself) ...
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Making bash TAB completion more like cmd.exe [duplicate]

I wondered if theres a way to do rotational style completion in bash similar to the behavoir on cmd.exe, I've found it speeds me up in regard to entering commands
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3answers
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what does it mean a red filename shown with black background?

I have a compilation problem, and when I check my lib/ directory I get this output from "ls": What the red/black combination mean? I checked in the output of "dircolors -p" as suggested here ...
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Shell SIGKILL Keybinding

How can I setup a keybinding to send a SIGKILL to the current foreground job? I already know that Ctrl+C is SIGINT and Ctrl+\ is SIGQUIT. I would like a more severe option. Is there anything ...
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Runing a command without inheriting parent's environment

Is there a way to run a command "as if" it is in a new login session? I've already tried env -i. However, I don't want to deal with various ENV variables I have to set or unset. I've also tried bash ...
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1answer
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HOSTNAME environment variable on Linux

On my Linux box (Gentoo Linux 2.6.31 to be specific) I have noticed that the HOSTNAME environment variable is available in my shell, but not in scripts. For example, $ echo $HOSTNAME returns ...
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1answer
381 views

How can you reverse the direction of alt-period in Bash?

In Bash, you can press Alt-. to insert the last argument of the previous command. If you press it multiple times, it cycles through the last arguments of all of the commands in your history. However, ...
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What parameters does ulimit have?

I see in examples that the -u option is used with the ulimit command, but I cannot find documentation that says what that option means. man ulimit shows the manual for a system library function. What ...
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UNIX shell scripting: how to recursively move files up one directory?

I have a large number of small files, f, arranged in a directory structure like so: /A/B/C/f There are 11 directories at the level of A, each with about 100 directories at the level of B, each with ...
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How can I keep the color when I run the external command inside vim?

For example, for the command ls --color displays colorful results when being executed in the shell. However, when I call :!ls --color inside vim, all color information is gone. What should I do to ...
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Is it possible to set wget to show the transfer times in milliseconds?

Generally, wget shows transfer times in seconds. Is there a way I can to make it show the time in milliseconds?
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What do these cryptic strings really mean in registry associations?

Looking at my HKEY_CLASSES_ROOT\Word.Document.12\shell\Open\command\command value (Word 2010 'Open' shell association) I see this sort of nonsense: ...
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393 views

Is it possible to configure the way bash completes directory names?

I'd like to instruct bash to use a special method to perform completion on certain directory names. For example, bash would call a program of mine to perform completion if a path starts with "$$", and ...
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1answer
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versions of netcat

I've tried the two main versions of netcat : GNU and BSD. (mine is BSD Version). On GNU version, the command $ nc -l -p 12345 works fine but with BSD, option -l (listen) can't be used in conjonction ...
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160 views

Windows 7 coming from Linux/Unix?

I've got a Windows 7 box going for my job, and most high-level computing experience is coming from shell environments in Linux. I'm completely lost in the Windows shell, and when I try to use a GUI ...
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476 views

Tabbed terminal that connects to a GNU Screen session?

I use the session feature of screen extensively. For example, I'll start a screen session for "project1" as "screen -S project1", and then when I need to reconnect I use "screen -d -r project1". ...
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281 views

What to use for Shell Access? [closed]

I just purchased a virtual dedicated server-plan that comes with shell access. It's been a while since I've actually used shell access remotely, so I'm a bit behind the times. Years ago I used PuTTY, ...
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What does ~ mean in a Linux shell?

I'm new to Linux and have been seeing this often. Could someone explain the concept here? ~/.somefilename What does the ~ (tilde) signify?
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Why are not all files compressed and how to improve the solution

I have a folder with about 20K files. The files are named according to the pattern xy_{\d1,5}_{\d4}\.abc, e.g xy_12345_1234.abc. I wanted to compress the first 10K of them using this command: ls | ...
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8answers
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Remove linux file named with set of shell responsive characters

I've created a file named \;:$"\' to test a software of mine. I ended up with an error, because I cannot delete the file property. I'm trying to find a precise character combination to remove it via ...
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3answers
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How to join files on the command line without creating temp files?

I have two files in a Linux / Bash environment: # Example data $ cat abc 2 a 1 b 3 c $ cat bcd 5 c 2 b 1 d I'm trying to join the two files on the first column. ...
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How to “undo” unzip command?

I used "unzip XXX.zip" to extract a zip file, unfortunaly, i make a mistake. Now i want to delete all the file and directorys generated by "unzip". How can I undo it?
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2answers
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how to delete all characters after cursor in shell

I want to delete all characters after cursor in putty or shell. How can i achieve this? Every time I want to delete the complete line, I need to press delete key and that is something I don't want to ...
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2answers
2k views

Smart tab completion (for directories)?

Are there shell versions that have a more intelligent tab completion? I'd like to be able to type cd foo-<TAB> Then it would show me the possible completions along with numbers that I can ...
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505 views

Documenting Unix commands on the command line

I would like to append both the last command and the output of the last command to a text file for the purpose of a tutorial. For example: After I do an ls in my home directory I see this on the ...
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6answers
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Why does my LD_LIBRARY_PATH get unset launching terminal?

I have a shell script to set up some environment variables and launch whatever program I send in as an argument: export PATH=$HOME/local/bin:$PATH export ...
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2answers
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How do I make “find” exclude the folder it searches in?

I'm running the following command: find /var/www/html/content/processing -type d -mtime +1 -exec rm -rf {} \; I would like to delete all the folders under the processing folder (the processing ...
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3answers
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Disable color in shell/terminal

I want to disable all color in my shell. Not ls, not nano, not vi, nothing. What's the best way to achieve this?