205
votes
23answers
110k views

How to execute a command whenever a file changes?

I want a quick and simple way to execute a command whenever a file changes. I want something very simple, something I will leave running on a terminal and close it whenever I'm finished working with ...
205
votes
8answers
209k views

What is the “You have new mail” message in Linux/UNIX?

Sometimes, when I log into a box and 'su' to root, I get a cute little message saying I have mail (thank GOD it's not AOL). Where is this mail? What does it contain? Who/What sent it? How important ...
203
votes
4answers
258k views

What are PATH and other environment variables, and how can I set or use them?

Questions about setting environment variables the PATH are very common here, and in most cases the answers are very similar to each other. In the future it would be nice to have a good Q/A for ...
203
votes
2answers
5k views

How do I reset the time on my computer without turning it on?

Alright, so today, I did something very stupid: Do an experiment on my computer without backing it up. So I saw that the calendar in Windows could only go up to 12/31/2999 (or something like that). ...
197
votes
6answers
210k views

Inverting direction of mouse scroll wheel

Is there a way to make a mouse scroll wheel invert its direction? I'd like to scroll upwards and have that action scroll downwards and vice-versa. There is no setting on the Mouse control panel that ...
197
votes
10answers
49k views

Is there still a reason to choose a 10,000 RPM hard drive over an SSD?

For anyone who's serious about storage performance, SSDs are always the fastest solution. However, WD still makes their 10,000 RPM VelociRaptor hard drives, and a few enthusiasts even use ...
195
votes
2answers
197k views

How to remove an entry from Chrome's Remembered URLs from the url bar?

I've got a URL in Chrome "local.mysite.com" that autopopulates when I start typing "local.my" into the URL bar. Note that this URL DOES NOT EXIST in my browser history (at ...
194
votes
18answers
355k views

How can I download an entire website?

How can I download all pages from a website? Any platform is fine.
194
votes
14answers
119k views

How do you list all processes on the command line in Windows?

Is there a command equivalent to 'ps' on Unix that can list all processes on a Windows machine?
192
votes
13answers
344k views

How can I send a Ctrl+Alt+Delete through Remote Desktop in Windows 8?

I need to send a CtrlAltDelete to a remote machine through Remote Desktop. The CtrlAltDelete is being intercepted by Windows 8, regardless of whether the remote desktop has focus or is in full screen. ...
192
votes
6answers
106k views

How to control Windows 7 snap feature with two monitors?

There is the Snap feature in Windows 7. But it seems to not work when dragging window to the edge that are adjoin to the second monitor. How to make it working? May be some regedit cheat or something? ...
192
votes
2answers
70k views

Assigning custom extensions to a language's syntax highlighting in Notepad++

In the current version of Notepad++ opening .sql files results in Notepad applying SQL syntax highlighting to it. I'd like Notepad++ to do the same for other extensions as well, is there some setting ...
191
votes
12answers
37k views

How can I change to the previous directory instead of going up?

I currently spend a lot of my working hours moving back and forth between two paths which are very far down the tree and divert from each other at root. It strikes me that my life would be a lot ...
191
votes
6answers
185k views

In Mac OS, what is the keyboard shortcut to switch between windows of the same application?

I often use the Cmd+Tab shortcut to switch between different applications (for example: Xcode and Google Chrome), but is there a shortcut to switch between different windows of the same application ...
190
votes
5answers
437k views

How can I display the contents of an environment variable from the command prompt in Windows 7?

In Windows 7, when I start the Command prompt, is there any command to display the contents of an environment variable (such as the JAVA_HOME or PATH variables)? I have tried with echo $PATH, echo ...
190
votes
6answers
88k views

How can one turn off spell checking in Notepad++?

Notepad++ recently added built-in support for spell checking, and it is enabled by default. Where can I turn it off?
189
votes
6answers
100k views

Should laptops remain plugged in when their battery is 100% charged?

When your laptop's battery is 100% charged, should you leave it plugged in so any battery power doesn't get used, or will that cause overcharging, overheating, etc.? Should the laptop be unplugged ...
188
votes
7answers
208k views

Can I delete the the folder C:\ProgramData\Package Cache\?

There is a new folder full of installers located at C:\ProgramData\Package Cache\. I believe this is from visual studio 2012 RC. Does anyone know if I can delete these GB of data without ...
188
votes
9answers
13k views

How far will you get with an 'rm -rf /' command?

I've often wondered how far the system will actually get if you run rm -rf /. I doubt the OS would be able to erase itself (?) Bonus Question: After the command has been executed, will rm have ...
187
votes
18answers
22k views

What is the advantage of using 'tar' today?

I know that tar was made for tape archives back in the day, but today we have archive file formats that both aggregate files and perform compression within the same logical file format. Questions: ...
187
votes
8answers
160k views

How to tell git which private key to use?

ssh has the -i option to tell which private key file to use when authenticating: -i identity_fileSelects a file from which the identity (private key) for RSA or DSA authentication is read.  ...
187
votes
2answers
92k views

“directory junction” vs “directory symbolic link”?

MKLINK [[/D] | [/H] | [/J]] Link Target /D Creates a directory symbolic link. Default is a file symbolic link. /H Creates a hard link instead of a symbolic link. /J ...
185
votes
11answers
58k views

How do I reorder tmux windows?

In screen, I can just type C-a :number 0 to move a window to the top of the window list and push all the other windows down one. What's the equivalent command sequence for tmux? I looked at the man ...
185
votes
4answers
12k views

What is the purpose of the holes marked “Do Not Cover” on hard drives?

On many hard drives, there's a text warning to "not cover this hole", sometimes adding that doing so will void the warranty. What is the purpose of this hole and why would covering it cause damage or ...
182
votes
1answer
262k views

How to remove one or all auto-complete text entries in Chrome? [duplicate]

Possible Duplicate: Remove auto-complete field entries in Google Chrome Ok... so this is embarrassing. I typed in "boobs" on EncyclopediaDramatica's search because, well, it's a really ...
181
votes
24answers
9k views

What are some options for transfering large files without using the Internet? [closed]

My employer's Internet connection is extremely slow. It's a $6,000 a month, 9 Mb, bonded T1, shared by over 150 users. It's not untypical to see regular file transfer speeds of 20-100 KBps. And ...
180
votes
8answers
200k views

How to check which apache modules are enabled/installed?

Which is the most elegant way to check which apache modules are enabled?
179
votes
19answers
36k views

32-bit vs. 64-bit systems

What are the differences between 32-bit and 64-bit systems? If you have used both of them, what kind of sharp differences have you experienced? Would it be a problem to use 32-bit programs on ...
178
votes
5answers
440k views

How do I get the distinct/unique values in a column in Excel?

If I have a column with values, and I want to find out what distinct values are in there (not how many - but the actual distinct values), how can I do that? In SQL Server I would do something like ...
177
votes
8answers
11k views

What do the parentheses and number after a Unix command or C function mean?

I keep seeing parentheses and a number after a command in Unix or Linux or C function. For example: man(8), ftok(2), mount(8), etc. What do these mean? I see them in man too.
176
votes
4answers
113k views

How to pin either a Shortcut or a Batch file to the new Windows 7, 8 and 10 Taskbar and start menu?

We are having trouble adding our batch scripts to the Windows 7, 8 or 10 taskbar or start menu. Our batchfiles take some arguments and just execute other application based on those arguments . To ...
175
votes
10answers
35k views

How to copy text from Console2?

I just started using Console2 as an alternative to cmd.exe I can't figure out how to copy text from the console to the clipboard -- dragging over it with the mouse won't mark anything, and there is ...
173
votes
18answers
247k views

Move an off-screen window back on-screen on Mac OS X

It seems that Mac OS X 10.6.1 Snow Leopard has a tendency to leave some windows off-screen at times, especially when I disconnect an external monitor from my MacBook. How can I move the window back ...
171
votes
8answers
189k views

Getting curl to output HTTP status code?

I'm using curl at the command line on Linux to issue HTTP requests. The response bodies are printed to standard out, which is fine, but I can't see from the man page how to get curl to print the ...
171
votes
9answers
240k views

Find out which process is locking a file or folder in Windows

How can I find out which process is locking a file or folder in Windows? For instance, when trying to delete a folder, Windows reports this: The action can't be completed because the folder is ...
171
votes
9answers
21k views

Why does emptying disk space speed up computers?

I have been looking at a bunch of videos and now understand a bit better how computers work. I better understand what RAM is, volatile and non-volatile memory, and the process of swapping. I also ...
170
votes
25answers
160k views

What can I do to stop the Play / Pause button from opening iTunes?

In Snow Leopard the Play / Pause media button (on the F8 key) opens up iTunes. How can I disable that? Preferably keeping the old Leopard behaviour, so I can use it to control other media applications ...
168
votes
14answers
151k views

How do I detach a process from Terminal, entirely?

I use Tilda (drop-down terminal) on Ubuntu as my "command central" - pretty much the way others might use GNOME Do, Quicksilver or Launchy. However, I'm struggling with how to completely detach a ...
167
votes
6answers
141k views

How can I delete a symbolic link?

I created a symlink using mklink. Now I need to change it but I can't figure out how to delete it so I can recreate it correctly.
167
votes
12answers
21k views

Why are pixels square?

Pixels in screens are square, but I'm not sure why. Both pixelated images look pretty bad - but I'm not sure there's any advantage of squares over hexagons here. Hexagons also divide up into 3 ...
166
votes
22answers
183k views

Is there a built-in checksum utility on Windows 7?

Is there a built-in checksum/hash utility on Windows 7?
165
votes
14answers
326k views

How to download files from command line in Windows, like Wget is doing?

How can I download something from the web directly without Internet Explorer or Firefox opening Acrobat Reader/Quicktime/MS Word/whatever? I'm using Windows, so a Windows version of Wget would ...
165
votes
14answers
289k views

Is there a way to “auto login” in PuTTY with a password?

Is there a way to configure a password for a stored session in PuTTY? I know there is the capability to specify an "auto-login username" (under Connection/Data), but is there a way to do the same ...
162
votes
16answers
324k views

How do I place a bootable ISO on a USB drive?

What's the best way of placing a bootable ISO on a USB drive, such that the drive is bootable? ISOs such as a live Linux preview disk, Windows installation ISO, etc.
159
votes
10answers
74k views

Get colors in 'less'' command

when I read a file in Linux with the command 'less' or 'more', how can I get the content in colors?
159
votes
7answers
145k views

How to list files of a Debian package without install

This command can only list contents of installed packages, dpkg -L PACKAGENAME but how to list contents of a non-installed package, to preview/examine the package?
159
votes
15answers
26k views

Is the performance of a CPU affected as it ages? [closed]

This is a hypothetical question about how a CPU operates. If I purchase two identical CPUs, and use one long term (say one year), will it be identical in speed to the unused CPU? Will the number of ...
159
votes
3answers
150k views

Go back to previous directory in shell

Is there a way to go back to previous directory we were in using bash,tcsh without using pushd/popd ? I'd like to type something like "back" and got returned to the previous directory I was in. Edit: ...
158
votes
8answers
251k views

How to get the summarized sizes of folders and their subfolders?

Let's say I want to get the size of each folder of a linux file system. When I use ls -la I don't really get the summarized size of the folders. If I use df I get the size of each mounted file system ...
158
votes
9answers
315k views

Mac OS X: Best Way to Make an ISO from a CD or DVD

Both command-line and screen-oriented pointers appreciated! update: I verified the disk utility, hdiutil, and dd methods. dd seems the fastest, 30 minutes on my macbook pro vs. 40 minutes for ...

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