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

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31
votes
2answers
16k views

Setting environment variable for just one command in Windows cmd.exe

In Bash, I can do EDITOR=vim command and command will be run with EDITOR set to vim, but this won't affect the value of EDITOR in the shell itself. Is it possible to do this in cmd.exe?
30
votes
5answers
3k views

Deleting millions of files

I had a dir fill up with millions of gif images. Too many for rm command. I have been trying the find command like this: find . -name "*.gif" -print0 | xargs -0 rm Problem is, it bogs down my ...
30
votes
6answers
23k views

zsh with Cygwin

How can I configure zsh to be the default shell under Cygwin?
30
votes
7answers
70k views

List open SSH tunnels

I use a lot of SSH tunnels to various servers on my linux machine (for tunnelling to databases, web servers etc) and it would be really handy to view a list of current open tunnels via a shell script. ...
29
votes
9answers
4k views

Any shortcut for “cd ..”?

Is there any shortcut for cd ..?
29
votes
4answers
49k views

Delete matching files in all subdirectories

How can I remove all .swp files in all of my subdirectories under Linux?
28
votes
7answers
74k views

How can I use a bash like shell on windows

I use Linux and a Mac. I'll be teaching some command line stuff soon. What can I install on Windows to give me a terminal window most similar to a basic mac/linux bash shell. Would like to be able to ...
28
votes
6answers
30k views

How to find my stolen Macbook

A friend of mine just had her Macbook stolen. Her Dropbox account is still working on the Macbook, so she can see each time the Macbook comes online, and she can get its IP address. She has given ...
28
votes
7answers
103k views

How do I run the Windows 7 Explorer shell with Administrator Privileges by default?

The Windows 7 shell (Explorer) can be made to run with Administrator privileges by this manual process: Kill Explorer shell by holding down Shift+Ctrl, right-clicking the Shut down button in the ...
27
votes
8answers
7k views

Is it possible to restart a computer in response to an email notification?

I'm looking for a way to reboot machines after getting an email notification. The setup I want to use this on is a render farm. We have 5 boxes with 8 Nvidia GTX 980Ti in them. They're running ...
27
votes
6answers
8k views

What zsh features do you use? [closed]

I do a lot of work in the terminal so I have learned a lot about my shell of choice, zsh. What features of zsh do you use to make yourself that much more productive at work? One of my favorites is ...
27
votes
4answers
15k views

How do I change a users default shell in OSX?

What is the correct OSX way of changing a users default shell? When I googled for it I found several references to an application called NetInfo Manager but I couldn't find it on my system. There were ...
27
votes
2answers
17k views

Bash Shebang for dummies?

I have some bash scripts I have setup that mostly use #!/bin/bash but I regularly come across some that look like #!/bin/bash -e #!/bin/bash -x #!/bin/bash -ex and so on. Can someone explain ...
27
votes
5answers
14k views

What is the difference between bash and sh?

I see two types of code being used: #!/usr/bin/sh and: #!/user/bin/bash I searched for this online and opinions vary a lot. The explanations I saw on most websites say that sh is older than ...
27
votes
3answers
24k views

Mac OS X: conventional places where binary files should live

I've downloaded an application that is a command-line application, and want to put it somewhere where I can run it from the command-line without having to type the path explicitly. What are the ...
26
votes
6answers
64k views

why run a Linux shell command with &?

I am using Red Hat Linux Enterprise version 5. I've noticed people sometimes running commands with a couple of & options. For example, in the below command, there are two & signs. What is the ...
26
votes
7answers
34k views

Find and delete all the directories named “test” in linux

I have many directories named "test" and I would like to remove them. I know how to find them and print them using: find . -name test -print Now, how to do I remove the directories? Please note ...
26
votes
4answers
41k views

How do I find (and kill) process running on a certain port? [duplicate]

Possible Duplicate: Finding the process that is using a certain port in Linux I'm using Ubuntu Linux 11.04. How do I write a shell script expression that will find the process running on ...
26
votes
2answers
10k views

Re-enter interactive mode after Ctrl-z

In interactive mode (in Octave, gnuplot, R, etc.) I occasionally press Control + z by mistake. This pauses the program and kicks me back to the terminal. Is it possible to re-enter the original ...
25
votes
6answers
16k views

How can I change all files belonging to one user to another user?

I'm looking for a Linux command that can change ownership of all files belonging to a given user, preferably in a targeted directory, to another specified user. My dream command would look something ...
25
votes
5answers
86k views

How can I edit the $PATH on linux?

I am using ubuntu 9.04 I need to add some folder to my $PATH. I know how to read the path: echo $PATH I want to be able to edit it and add 2 other paths. Thanks
24
votes
3answers
20k views

What are the differences between fish and zsh? [closed]

I'm a bash user willing to switch to a more friendly and advanced shell. I read a lot of good things about zsh, but I gave a quick test at fish and it seems great too. Both seem very close in term of ...
22
votes
3answers
13k views

How to remove shell integration of Notepad++?

I need to remove the annoying shell integration of Notepad++. How do I do that, please?
22
votes
3answers
21k views

What is the difference between CMD and Command prompt in windows?

Until now, I never thought (and never observed) that cmd and command are two different things. Well, are they? Take a look at this pic: Actually, I usually open cmd from the Run dialog whenever I ...
22
votes
5answers
10k views

Bash/ZSH: Undoing 'disown'

Is there a way to 'reattach' a process to the shells job table after it it has been 'disowned'? Edit: $SEARCHENGINE totally fails me. Doesn't look too good.
22
votes
4answers
25k views

Clear terminal using keyboard shortcut

I was curious if there is a way to clear the terminal buffer/output through some keyboard shortcut. I am using Ubuntu. I am aware that Ctrl + L clears the terminal, but you can still scroll back to ...
22
votes
3answers
5k views

Multiple standard input? How?

From this commandlinefu post: $ diff <(wget -q -O - URL1) <(wget -q -O - URL2) Seems like multiple standard inputs but---if I remember my Linux Porgramming course correctly---this can't be ...
22
votes
1answer
6k views

ZSH Completion colors and OS X

Consider this minimal .zshrc : export CLICOLOR=1; export LSCOLORS=exfxcxdxbxegedabagacad; # It is the default value on OSX, so this line can be omitted autoload -Uz compinit compinit zstyle ...
21
votes
3answers
10k views

Random password generator: many, in columns, on command line, in Linux

A while back, I came across a random password generator for the command line that displayed a grid of "memorable" passwords. Output was something like this: adam@host:~$ CantRememberThisCommand ...
21
votes
3answers
7k views

Use GNU screen as login “shell”

What's the best way to have screen automatically run when you open a new shell, whether by login, xterm, or anything else? I see the most common recommendation is to put exec screen in your regular ...
20
votes
10answers
59k views

How to resume CUPS printer from command line?

I have printer in CUPS that due to driver problems (HP 1010) from time to time goes into pause. I would like to write a shell script that will execute once per hour to resume a printer in CUPS. But ...
20
votes
5answers
3k views

Finding the definition of a bash function

I work in an environment that has a lot of legacy shell script magic lying around. One thing used heavy from the command line are bash functions that get sourced from some file included from some ...
20
votes
4answers
5k views

Equivalent/Alternatives for Alt+Dot in Mac

One thing i miss from the Linux shell is the Alt+Dot shortcut. What it does is insert the last argument of the previous command. It appears to be a trivial technique, but it's really useful. i.e. if ...
20
votes
2answers
20k views

Run or send a command to a tmux pane in a running tmux session

I want to write a shell script which will attach to a named tmux session, select a window (or pane) in that session and run a command in that selected window (or pane). How do I do this from a bash ...
20
votes
2answers
7k views

Putty SSH: CTRL+Cursor keys don't work skip to previous/next word

When I am connected to my local Ubuntu dev server with putty (from my Windows 7 box) via SSH, the following key combinations don't work to move the cursor forward and backward on word boundaries: ...
20
votes
3answers
11k views

Screen a running process

Sometimes I forget to run a program under a screen session and can't stop it in the middle, and I know it's going to take long. Is there a way to screen an already running process without restarting ...
18
votes
5answers
20k views

Console like Gnome Terminal for Windows [closed]

I'm looking for console like the Gnome Terminal for Windows to replace cmd.exe. I'd like to have tabs and easy copy&paste. Do you know a tool like that?
18
votes
8answers
30k views

Make ls sort by file type (then name)

By default the ls command sorts just by filename, but I want directories to appear before other file types. I might even want files to be sorted by extension, like the way Windows explorer sorts by ...
18
votes
6answers
24k views

Will rm -rf * remove all files/folders in the current directory?

Will rm -rf * remove all files/folders in the current directory ? I want to make sure the wildcard * won't move up in upper directories and erase all my filesystem. :D I remember doing chmod 777 .* ...
18
votes
6answers
15k views

Full command text with unix ps

When we enter: ps -f ... the CMD column text doesn't show the full command. Any way to prevent this truncating? Seems like it's showing the first 80 characters. We are running a fairly ...
18
votes
3answers
24k views

How do I fork a process that doesn't die when shell exits?

If I run emacs from the shell: $ emacs foo & and then kill that shell, emacs dies. How can I run a command so that it will not die when the shell dies? I found references to nohup, but that ...
18
votes
4answers
81k views

How to display current path in command prompt in linux's sh (not bash)?

I would like to display current path in sh prompt (not bash shell), which currently just shows "#", I tried with introducing this env PS1="$(whoami)@$(hostname):$(pwd)" and set ...
18
votes
7answers
9k views

How to retrieve the absolute path of an arbitrary file from the OS X

I'm looking for a simple command that can be used within Bash to find the absolute and canonicalized path to a file on an OS X (similar to `readlink -f' under Linux). The following sample bash ...
18
votes
4answers
12k views

Why is the size of a directory always 4096 bytes in unix?

I am sure a directory file has much less information than 4096 bytes. I know the sector size is 4096 bytes. But normal files smaller than that do exist. Why does Unix reserve 4096 bytes for each ...
18
votes
3answers
6k views

Using wildcards in commands with zsh

Using commands such as rsync and scp with ZSH I've run into trouble. Instead of the (normal) behaviour of giving me all matching files, it won't run and returns: ➜ ~ rsync -azP user@server:~/* ~/ ...
18
votes
7answers
19k views

Stop Windows 7 Explorer from automatically expanding folders

Windows 7 Explorer can be opened in any folder from the command line. But, it automatically expands (on the left nav panel) the Favorites, Desktop, and [Username] folders. This makes it hard to see ...
18
votes
1answer
4k views

Why do we have login, non-login, interactive, and non-interactive bash shells?

So the bash man pages explain what login and interactive shells are: A login shell is one whose first character of argument zero is a -, or one started with the --login option. An ...
17
votes
3answers
3k views

Why does clang generate unintelligible text when redirected?

I am trying to save the output of a command to a file. The command is: clang -Xclang -ast-dump -fsyntax-only main.cpp > output.txt However the resulting output.txt file when opened (by gedit and ...
17
votes
9answers
50k views

Opening Explorer shell with admin privileges on XP (with IE7 installed)

I used to demote my user account so that it had no admin priveleges and used a 'sudo-like' trick where you create a shortcut to IE6 and enabled the 'Run with different credentials' option to open a ...
17
votes
3answers
7k views

How can I do Ctrl-Z and bg in one keypress to make process continue in background?

I follow this pattern of suspending the task and then letting it to continue too often with the Ctrl-Z bg sequence. I was wondering is there any way to compress that to single keypress? My shell is ...