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

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5answers
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Is there a way to edit files inside of a zip file without explicitly extracting them first?

I sometimes need to make changes to a .zip or .jar file, so I usually move the file to /tmp, extract all the files with unzip, edit a few files, and then re-zip up the files. This works, but it can ...
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 ...
16
votes
2answers
36k views

how to bring a background job to foreground

in Linux/shell, how can I bring background jobs to foreground and vice versa?
16
votes
10answers
18k views

Mac OS X - Could not start Terminal.app - shell has illegal value

I can not run the Terminal.app after rolling back my system from time machine. Mac OS X Version 10.6.2 It displays the following error. "Your are not authorized to run this application" "The ...
16
votes
4answers
6k views

How to set terminal size in Android adb shell?

When I connect to Android using "adb shell" and run certain commands such as "vim" or "mc", they are restricted to a "window" of 25x80 characters. Since I'm connecting from a desktop computer where ...
16
votes
9answers
14k views

Command aliases in Command Prompt?

How can I make command aliases in Windows' Command Prompt like I would with bash? I found out about doskey in a forum thread, so I can do something like: doskey ls=dir /b ...and now the command ls ...
16
votes
4answers
15k views

How to diff directories for different files, but not line-by-line

I want to see, recursively, files that are different in two directories. Diff can do this, but it shows me the line-by-line differences, which I don't want. Is there a tool that does this, or a way to ...
16
votes
1answer
29k views

When creating a symbolic link, how do I troubleshoot 'too many levels of symbolic links'?

I'm trying to create a symbolic link on Ubuntu 10.04 it says: me@laptop:~/PHPUnit$ ls assertions.php LICENSE PHPUnit README.markdown build.xml package.xml phpunit.bat ...
16
votes
2answers
17k views

Unix: How to merge two directories

Say I have two folders with various content, foo and bar. How can I merge bar into foo so that: Files in foo that are not in bar are untouched. Files in bar that are not in foo are now in foo. Files ...
16
votes
3answers
12k views

Check number of pending security updates in Ubuntu

Let me start by saying I have been forbidden to enable automatic updates on our Ubuntu servers, for both security and regular packages. When I log into any of my four Ubuntu servers, the welcome ...
16
votes
3answers
2k views

Prevent currently running linux task to be killed after logout from SSH

I have a computational task running for a few days on a linux server via SSH connection. It is not on the background, so the SSH connection is under hold of the task. I want to restart the local ...
16
votes
5answers
14k views

Linux Shell: Copy output into clipboard w/o using the Mouse?

Is it possible to copy the output into the clipboard without using the mouse? For example, I would like to do something like this: $ pwd >> clipboard
16
votes
6answers
320 views

Want to try out Linux, what do?

I've been learning ruby on rails for a while. At first I resisted using the console, but after a while I can say that I LOVE it. If Linux is anything like that, I think it's going to be legit. I ...
15
votes
4answers
2k views

dir C: vs dir C:\

I've accidentally found that if I do: dir C:\ I get a list of files that are direct children of the C: drive, in the root. However, if I do: dir C: I get a huge list of files that I'm not even ...
15
votes
4answers
3k views

A command before every bash command

Does anyone know a mean of putting a 'time' command before every command in a bash session?
15
votes
2answers
4k views

How to use a pipe to edit a file with vi

Lets say I have a file called file.txt. In it is a name of a file that I want to edit with vi. I want to do something like this so that I can edit the file: cat file.txt | vi However, that doesn't ...
15
votes
3answers
14k views

What's the difference between /etc/bash.bashrc and ~/.bashrc? Which one should I use?

When should I use each of the two .bashrc files to set my aliases, prompt, etc?
15
votes
3answers
3k views

How can I prevent tmux exiting with Ctrl-d?

I use tmux on my server and recently I found to my cost that ctrl-d will exit tmux and lose all the session information, my intention was to simply end the ssh session but failed to notice I was still ...
15
votes
4answers
2k views

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 ...
15
votes
3answers
10k views

How to update bash on Mac OS X Yosemite

Just trying to learn bash scripting a little. My old bash version: Bash version 3.2.53(1)-release... I've updated my bash on mac os x yosemite with homebrew: brew update brew install bash Then ...
14
votes
4answers
36k views

How do I rename files with spaces using the Linux shell?

I named a number of files with spaces in them, and I want to replace the space with "_". However, every time I write a command in the shell with the file name (eg "Spring 2011"), the shell doesn't ...
14
votes
7answers
26k views

How can I list only non-empty files using ls?

How can I list (using ls) all files that are not empty (size > 0) using linux?
14
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7answers
1k views

Is there a way to go to any directory from any other directory directly?

Is there a way to go to any directory from any other directory directly? For example, lets say that I'm at root and I wanted to go directly to currentProject without doing: cd dropbox/dev/...
14
votes
9answers
11k views

How do I copy file named starting with a dot?

I am trying to copy all files under directory A to directory B. All files under directory A are starting with dot, for example: A/.a A/.b A/.c which I found if I use: cp A/* B, always get error: ...
14
votes
3answers
23k views

Linux : To monitor a Service and restart if stopped?

Actually I'm not so sure whether i should use Shell Scripts, or if there some ways already. But whatever approach we use, i would like to keep a Service running all the time. Let's say iptables as an ...
14
votes
7answers
2k 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 ...
14
votes
7answers
22k views

Change directory using sudo

How to I change into a directory owned by root? If I do: sudo cd RootOwedDir I get: sudo cd: command not found If I su root I get: authentication failure, probably because I never really set up an ...
14
votes
6answers
3k views

How to show the current Vi mode when using Vi keybindings in the shell?

I use the vi keybindings in my tcsh shell. Now, I don't know which vi mode I'm in (insert mode or command mode), which leads to a lot of frustration. Does anyone know of a way to show the current ...
14
votes
2answers
14k views

How to calculate a relative path from two absolute paths in Linux shell?

We have two paths. First one is directory, second either a directory or a file. /a/b/c and /a/d/e.txt Relative path from first path to second will be: ../../d/e.txt How to calculate that in Linux ...
13
votes
7answers
19k views

How can I sort all files by size in a directory?

How can I display the files in a unix directory sorted by their human readable size, going from largest to smallest? I tried du -h | sort -V -k 1 but it does not seem to work.
13
votes
5answers
390 views
13
votes
4answers
2k views

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)?
13
votes
2answers
11k views

http get from the shell in Mac OS X

I'd like to download a link like: http://example.org/file.mp3 Now, I'm enough of a shell junkie to know what SCP does, but that's about where my geek-dom ends. So is there a shell program that lets ...
13
votes
4answers
2k views

bash: colorized man page

Where do I have to take a look at in the system to colorize the man pages? The man pages are viewed with less, so I tried adding the following lines to my .bashrc to change the colors: (Which works ...
13
votes
3answers
4k views

How can I launch a file properties dialog from the command line?

It's simple programmatically with ShellExecute to specify the properties verb when instructing Windows to open a file, but can this be done from the command line or run box? Ideally I'd like to do ...
12
votes
5answers
3k views

Which directory does path `//` represent in Linux?

When I want to go back to upper level directory in Linux by typing cd .., I typo-ed cd //. To my great surprise, no errors are reported. What's more the prompt becomes username@hostname://$. ls ...
12
votes
12answers
15k views

how to `tail` the latest file in a directory

In shell, how can I tail the latest file created in a directory?
12
votes
7answers
9k views

Best practices to alias the rm command and make it safer

Some time ago I erroneously deleted my home folder because I ran a rm -rf * on the wrong terminal, whose working directory was the home folder! I wish I had an alias for the rm command, but it was ...
12
votes
11answers
20k views

Is there any replacement for putty [closed]

Is there any nice looking terminal with more features and sexy looks than putty? I find it very boring.
12
votes
3answers
1k views

How to run a command in background with no output unless there's an error

How to suppress a command's output but show it if the command exit codes an error?
12
votes
4answers
2k views

Who deals with the star * in echo *

Who deals (interprets) the * in echo * Does the echo see the star or the shell take care about it and return a list of filename .. What about cp temp temp*
12
votes
3answers
10k views

Bash shell: list all files of type .png or .PNG?

In a bash script, how can I say 'for all files of type .png or .PNG'? I'm trying : for i in (`ls *.PNG` && `ls *.png`) but getting a syntax error.
12
votes
4answers
10k views

Terminal Vs. Shell [duplicate]

Possible Duplicate: What are the differences between shell , console & terminal? This probably sounds like a stupid question but I'm having a lot of trouble clearly differentiating between ...
12
votes
8answers
4k views

Growl Notifications for Shell Task Completion

(OSX Specific) I, like many others besides myself often find myself kicking off a process in the shell that takes a minute or two to complete (a large svn commit for example). During that time, I ...
12
votes
3answers
4k views

How do I host a mintty shell inside of Console2?

I like to use Console2 for my Windows shell work, where I usually make it open a cygwin bash prompt. I'd like to try out MinTTY (2), and want to host it within Console2 as well. If this is possible, ...
12
votes
1answer
3k views

ZSH tab completion of git commands is very slow. How can I turn it off?

If I type: rm <TAB> I'll see possible completions almost instantly. However, if I type: git rm <TAB> It'll hang for several seconds if it's in a git repo, or fail to show any ...
12
votes
2answers
4k views

Writing shell scripts that will run on any shell (using multiple shebang lines?)

I've just started getting deeper into shell scripting, and I've always just thrown my script in a file, marked it chmod +x and then done /path/to/script.sh and let whatever interpreter is the default ...
12
votes
3answers
3k views

Making Linux shell prompt show last return value

I'm currently on a Linux machine and the shell prompt is showing me the last return value and number of executed commands (picture included, with these numbers shown in purple). My own computer doesn'...
12
votes
2answers
22k views

The application “SomeApp.app” can’t be opened

Problem: after downloading an application in OS X Yosemite (10.10.x) trying to open the application (either from the command-line or by double-clicking the application) produces an "The application “...
11
votes
8answers
17k views

Windows Vista: How to execute a .exe program in the cmd “As Administrator”

Yes, that's it. I need to run a program .exe in the dos cmd line and it needs to run like when you right button and select "run as an administrator"