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

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Why does less tail mode stop working?

Using the less command on linux in tail mode (F command or less -f) consistently stops working on certain machines and/or certain files. New changes simply stop showing up. I know I've fixed this ...
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1answer
979 views

why doesn't a bash while loop exit when piping to terminated subcommand?

Why doesn't the command below exit? Rather than exit, the loop runs indefinitely. While I discovered this behavior using a more complex setup, the simplest form of the command reduces to the ...
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1answer
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How do I make OS X set the terminal title back to the original title when coming back from ssh?

Starting on OS X, I ssh into foo (a Linux box). My terminal title changes to foo. I then ssh into bar (another Linux box). My terminal title changes to bar. I log out of bar. My terminal title ...
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2answers
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How to move folder in unix using mv, only when target is on the same drive

I need to move a folder using unix mv command, but only if the target is in the same drive or the same filesystem. What would be the best approach?
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What's the difference between the terms “Shell” and “Bash”?

What is the the difference between "Shell" and "Bash" and what do these terms mean? As far as I know, there is no difference. But I've seen many books about "Shell" and others about "Bash"! So in ...
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how to `tail` the latest file in a directory

In shell, how can I tail the latest file created in a directory?
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4answers
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Parallel shell loops

I want to process many files and since I've here a bunch of cores I want to do it in parallel: for i in *.myfiles; do do_something $i `derived_params $i` other_params; done I know of a Makefile ...
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12answers
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Best way to organise one's sh/bash/python/etc. scripts

What is the best way to organise the sh/bash/python scripts you collect and write on your system?
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4answers
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echo newline character not working in bash

I have bash script which has lots of echo statements and also I aliased echo to echo -e both in .bash_profile and .bashrc, so that new lines are printed properly for a statement like echo ...
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2answers
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How can I found out if file is alias or symbolic link?

I'm working on a legacy system and I have a bunch of files that are referencing images that are located in other folders. lrwxrwxrwx 1 user nobody 56 Feb 10 2010 t100x100.jpg -> ...
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3answers
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What is the equivalent of bash's !$ and !! in the fish shell?

I've been using bash for a decade or so and have gotten used to being able to type !$ to repeat the last argument, e.g.: $ mkdir foo $ cd !$ cd foo (That last line is printed by the shell to tell ...
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Mouse cursor in Terminal?

I use Mac OS X Terminal.app. But the answer to this would probably apply to any typical UNIX-ish terminal emulator in a graphical environment. Question -- what do I do to: Use my mouse cursor to ...
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682 views

Figure out what non-symlink path would be?

On Linux, if I've cd'd around and am now in a directory, is there a way to figure out what the real path to that directory is if I had not used a symbolic link to get there? Consider: $ pwd ...
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1answer
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How do I unset or get rid of a bash function?

If you set or export an environment variable in bash, you can unset it. If you set an alias in bash, you can unalias it. But there doesn't seem to be an unfunction. Consider this (trivial) bash ...
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7answers
1k views

Is there any functional-like unix shell?

I'm (really) newbie to functional programming (in fact only had contact with it using python) but seems to be a good approach for some list-intensive tasks in a shell environment. I'd love to do ...
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1answer
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PowerShell vs. the Unix Shell

I've heard some things about the features of the PowerShell. Some of it seems like typical features of Unix shells. So it seems Powershell includes piping and the commandlets, similar to shell ...
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7answers
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Screen Capture - command line?

Is there a command line tool out there that can record your computer screen and audio device and then save that to a file?
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300 views

Is there a way of using ctrl-r after typing part of command in bash?

In bash the Ctrl+r command is very useful, I type Ctrl+r whatever and it searchs my history for commands containing the word whatever. But if I type whatever and realize that I would like search 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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3answers
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re-use '~/.profile` for Fish?

(I'm talking about the shell Fish, esp. Fish's Fish.) For Bash/ZSH, I had ~/.profile with some exports, aliases and other stuff. I don't want to have a separate config for environment variables for ...
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3answers
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Windows & Git Bash: Bash PATH to read Windows %PATH% system variable

I've recently added a directory to the Windows PATH manually by going into Control Panel -> System -> Advanced system settings -> Environment Variables -> User variables -> PATH. (Windows 7, 64-bit.) ...
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4answers
8k views

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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6answers
11k views

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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9answers
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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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8answers
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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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3answers
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how can i install CentOS 6 without the gui?

i just downloaded the centos 6 live cd and i tried installing it on virtually and i am never prompted to install centos with/without gui and its all automated. what happends is after i am booted into ...
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4answers
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How long is long for the Unix 'file' command?

When you pass a text file to the Unix file command, it might tell you something like: input.txt: UTF-8 Unicode English text, with very long lines Can somebody tell me the minimum number of ...
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4answers
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Bash Shell Tutorials [closed]

What are some good bash tutorials? I would like to learn more about the bash shells commands and how to use them.
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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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2answers
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Bash not loading '.profile' in new session on Linux

I'm setting up a new Linux machine I got from our IT dept, and noticed .profile is not loaded when I start a new terminal session. The current shell is Bash, though I changed it from the default sh it ...
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5answers
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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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1answer
12k views

du only for directories

In C-Shell, how can I get the same output as du -sh ./* but without listing the files in the root dir, i.e. just a list of subdirectories in ./ and the sizes of all their contents?
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6answers
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Clear stdin before reading

I have the following bash script: # do some time consuming task here read -p "Give me some input: " input Now as you might have guessed, if a user presses some random keys during the "time ...
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1answer
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Retrieve Linux command line history by date

I want to see what I typed on my bash command line on a certain day a week ago. Is there a way to retrieve command line history? Something like below, perhaps? > history --include-date | grep ...
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3answers
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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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3answers
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Is there a shell which supports fuzzy completion as in Sublime Text?

I'm using bash and I was wondering if there is any plugin in bash or other shell which allows me to do this cat tfnislong.txt + [tab] completes to cat ThisFileNameIsSoLong.txt just like tab completion ...
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1answer
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How can I kill Firefox by console?

I know I can type: ps -A | grep firefox I get something like: 6818 ? 00:04:23 firefox Now I can kill it by means of: kill -9 6818 How can it be done in one command and how can I make ...
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4answers
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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
531 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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2answers
14k views

How to change proxy setting using Command line in Mac OS?

I am using Mac OS and sometimes some work need to be done using a proxy so I need to change my proxy setting frequently. But changing proxy setting in System Preferences is very messy. Is there a ...
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105 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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4answers
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How do I combine stdout and stderr for different shells?

I know the answer for some shells, e.g. with cmd.exe you can: some.exe > out.txt 2>&1 How do you achieve the same for other shells (bash, ksh, tcsh, powershell, etc)?
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2answers
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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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4answers
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BASH history truncated to 500 lines on each login

For some reason, I cannot get my system to keep my BASH history after a reboot. Here are the relevant sections of my ~/.bashrc: shopt -s histappend PROMPT_COMMAND='history -a; updateWindowTitle' ...
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4answers
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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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1answer
22k views

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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3answers
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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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2answers
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What is the difference betwen /etc/environment and /etc/profile?

I understand that the former is used prior to the latter, but what is the conceptual difference? Is 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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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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8answers
981 views

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 ...