All Questions
509,772
questions
2427
votes
7
answers
3.1m
views
How do I make a POST request using curl?
How do I make a POST request using cURL's command-line tool?
Laurie Young
2154
votes
3
answers
252k
views
Why does Windows think that my wireless keyboard is a toaster?
I've inherited an old PC from my girlfriend's dad and when setting up the printer I got a bit of a surprise:
Two questions spring to mind here:
Why does Windows think my wireless keyboard is a ...
- 11.9k
2008
votes
15
answers
1.7m
views
How do I scroll in tmux?
How do I scroll with either the keyboard or mouse? The tmux man page indicates one must enter copy-mode to scroll. Is there a way to quickly scroll without manually entering copy-mode?
- 20.2k
1751
votes
10
answers
1.6m
views
How can I sort the output of 'ls' by last modified date?
How can I sort the output of ls by last modified date?
nearly_lunchtime
1582
votes
6
answers
164k
views
How do I make a machine "blank screen" for a period of time (as a penalty) if certain noise levels are reached?
My kids (4 and 5) yell a lot when playing games on the computer. I found an effective cure for this. When I hear loud noises, I ssh into the game computer and do:
chvt 3; sleep 15; chvt 7
This ...
- 8,533
1467
votes
19
answers
2.4m
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 ...
- 15.4k
1287
votes
16
answers
1.8m
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 ...
- 22.9k
1159
votes
25
answers
1.5m
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.
The ...
- 13k
1070
votes
17
answers
1.1m
views
How to clear/flush the DNS cache in Google Chrome?
As you probably know Google Chrome has its own internal DNS cache. Is there a way to clear it without having to wait for the time out or close the browser?
- 10.8k
1004
votes
20
answers
524k
views
What are the Windows A: and B: drives used for?
In Windows you have a C-drive. Everything labeled beyond that is with the following letter.
So your second drive is D, your DVD is E and if you put in a USB stick it becomes F and the following ...
861
votes
3
answers
178k
views
Transatlantic ping faster than sending a pixel to the screen?
John Carmack tweeted,
I can send an IP packet to Europe faster than I can send a pixel to the screen. How f’d up is that?
And if this weren’t John Carmack, I’d file it under “the interwebs being ...
- 7,618
809
votes
13
answers
874k
views
What does 'source' do?
$ whatis source
source: nothing appropriate.
$ man source
No manual entry for source
$ source
bash: source: filename argument required
source: usage: source filename [arguments]
It exists, and it is ...
- 8,758
806
votes
31
answers
994k
views
Is there a built-in checksum utility on Windows 7?
Is there a built-in checksum/hash utility on Windows 7?
- 8,417
806
votes
8
answers
2.7m
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 ...
- 28k
784
votes
10
answers
643k
views
How to recursively chmod all directories except files?
How to chmod 755 all directories but not files (recursively)?
Inversely, how to chmod only files (recursively) but no directories?
- 10.4k
764
votes
15
answers
327k
views
macOS keeps asking my ssh passphrase since I updated to Sierra
It used to remember the passphrase, but now it's asking it to me each time.
I've read that I need to regenerate the public key with this command, which I did:
ssh-keygen -y -f id_rsa > id_rsa.pub
...
- 7,761
715
votes
12
answers
809k
views
View list of files in ZIP archive on Linux
How can I view the list of files in a ZIP archive without decompressing it?
- 7,703
701
votes
5
answers
101k
views
Why does this PNG image display differently in Chrome & Firefox than in Safari and IE?
Check this image out:
On Chrome and Firefox it will show as a pear. Now, try to save it and look at it saved on your desktop. Also, try viewing in Safari or Internet Explorer. It will display as ...
- 3,739
684
votes
18
answers
84k
views
How are pseudorandom and truly random numbers different and why does it matter?
I've never quite got this. Just say you write a small program in any language at all which rolls some dice (just using dice as an example). After 600,000 rolls, each number would have been rolled ...
676
votes
18
answers
773k
views
How to copy with cp to include hidden files and hidden directories and their contents?
How can I make cp -r copy absolutely all of the files and directories in a directory
Requirements:
Include hidden files and hidden directories.
Be one single command with an flag to include the ...
- 15.8k
673
votes
17
answers
655k
views
How do I convert a video to GIF using ffmpeg, with reasonable quality?
I'm converting a video to GIF file with ffmpeg:
ffmpeg \
-i input.flv \
-ss 00:00:00.000 \
-pix_fmt rgb24 \
-r 10 \
-s 320x240 \
-t 00:00:10.000 \
output.gif
It works great, but output ...
- 6,840
665
votes
20
answers
394k
views
How to *disable* automatic reboots in Windows 10?
Windows 10 lets you 'schedule' a reboot for later. I want to disable it.
Evidently Windows scheduled itself for a reboot last night when I wasn't looking and just closed everything I had been working ...
- 12.2k
664
votes
12
answers
1.1m
views
How to stop an automatic redirect from “http://” to “https://” in Chrome
I had something set up wacky in our DNS setup which is now resolved.
The remaining problem is that chrome has cached the incorrect setup.
Specifically, when using Chrome http://example.com is now ...
- 6,749
654
votes
7
answers
957k
views
Permissions on private key in .ssh folder?
I changed my permissions in my .ssh folder and now when I use a piece of software that uses my private key, I have to type my password each time. What should my permissions be on my id_rsa file to ...
Jody G
653
votes
24
answers
331k
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 ...
- 7,557
649
votes
42
answers
568k
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 ...
- 13.4k
641
votes
5
answers
868k
views
How can I get the same SSID for multiple access points?
I need to upgrade my existing wireless infrastructure and this time I want 2 access points to cover my house, since I get blind spots no matter what with a single AP. I have physical cabling to my ...
- 6,827
638
votes
5
answers
1.7m
views
How to find a directory on linux?
I have a VPS with Suse Linux 10.3.
I've logged in via SSH/putty and am trying to find where my web files are located.
Since I'm uploading via FTP in a directory called httpdocs, I assume that this ...
- 14.4k
610
votes
15
answers
365k
views
When reading a file with `less` or `more`, how can I get the content in colors?
When I read a file in Linux with the command less or more, how can I get the content in colors?
- 8,813
608
votes
11
answers
262k
views
From a quality perspective, what is better: turning volume up in the software, in the OS, or on the speakers?
If music isn't loud enough, how do I get the best quality (even if the difference is in fact so small it's negligible)?
By making the music louder in my music player, game or other sound-producing ...
- 4,457
602
votes
9
answers
843k
views
Using ffmpeg to cut up video
I am using ffmpeg to cut out a section of a large file like this:
ffmpeg -i input.wmv -ss 60 -t 60 -acodec copy -vcodec copy output.wmv
The -ss part works fine but the -t is ignored. It correctly ...
- 6,149
601
votes
5
answers
288k
views
How do you reload your .vimrc file without restarting vim?
Can you edit your .vimrc file and reload it without having to restart Vim?
- 6,121
596
votes
12
answers
649k
views
Automatically answer 'Yes' when using apt-get install
Is there a way to make apt-get install automatically choose "yes" upon the Do you want to continue [y/N]? confirmation dialog?
- 6,957
586
votes
12
answers
347k
views
Can I make cURL fail with an exitCode different than 0 if the HTTP status code is not 200?
I was always assuming that when curl got an HTTP 500 response it was returning an exit code that meant failure (!= 0), but that seems to be not the case.
Is there a way I can I make cURL fail with an ...
- 6,161
581
votes
7
answers
783k
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 ...
- 16.8k
580
votes
16
answers
499k
views
Reload a Linux user's group assignments without logging out
When assigning a user's secondary group list using:
# usermod -G <grouplist> <user>
is it possible to force this group assignment to take effect without logging out all running sessions?
...
- 6,292
575
votes
3
answers
417k
views
"directory junction" vs "directory symbolic link"?
In the context of NTFS:
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 ...
- 27.6k
574
votes
4
answers
229k
views
How to turn off word-wrap in less
Short version:
How can I make the less utility in Linux not wrap lines?
Long version:
Often I need to view huge CSV files using less with hundreds of columns. I frequently only care about the first ...
- 9,462
569
votes
6
answers
210k
views
Difference between .bashrc and .bash_profile
What's the difference between .bashrc and .bash_profile and which one should I use?
- 9,113
568
votes
5
answers
805k
views
How do I run multiple commands on one line in PowerShell?
In a cmd prompt, you can run two commands on one line like so:
ipconfig /release & ipconfig /renew
When I run this command in PowerShell, I get:
Ampersand not allowed. The `&` operator is ...
- 9,534
562
votes
13
answers
3.3m
views
Windows 7 SP1 Windows Update stuck checking for updates
I installed Windows 7 fresh and installed SP1. Now, when I try to check manually for Windows Updates it just hangs on the Checking for updates screen.
I tried running the tools in How do I reset ...
- 6,123
552
votes
14
answers
533k
views
How do I make rm not give an error if a file doesn't exist?
I'm writing a makefile that will clean up some useless files at the end of the compilation. If a target has already been made, it will of course skip that target and the useless file may not be there....
- 8,712
543
votes
6
answers
583k
views
Remove audio from video file with FFmpeg
How can I strip the audio track out of a video file with FFmpeg?
- 5,677
540
votes
6
answers
1.3m
views
How to decompress a .bz2 file
I have a file as: filename.bz2 I need to decompress.
I have tried the command: tar xvjf filename.tar.bz2, but it didn't work as the file is not a tar file.
How do I decompress this file?
- 5,545
529
votes
9
answers
926k
views
How to remove systemd services
If I install a new service then decide I don’t want that application anymore and delete it, the service is still listed in the output from systemctl as error.
Where is this coming from and how can I ...
- 5,391
521
votes
16
answers
829k
views
How to fix warning about ECDSA host key
I'm trying to setup password-less SSH on an Ubuntu server with ssh-copy-id myuser@myserver, but I'm getting the error:
Warning: the ECDSA host key for 'myserver' differs from the key for the IP ...
- 9,302
517
votes
12
answers
311k
views
Create/rename a file/folder that begins with a dot in Windows?
Many programs needs folder names that starts with a dot, like .emacs.d, .gimp-2.2, .jedit etc. How do I create such a folder?
When using the Windows Explorer in Windows 2000 (and other versions), I ...
Adventure10
512
votes
15
answers
2.6m
views
How to enable execution of PowerShell scripts?
When I try to execute my PowerShell script I get this error:
File C:\Common\Scripts\hello.ps1 cannot be loaded because the execution of scripts is disabled on this system. Please see "get-help ...
- 12.6k
511
votes
18
answers
768k
views
How to clear the contents of a file from the command line?
I have a log file that has a bunch of stuff in it that I don't need anymore. I want to clear the contents.
I know how to print the contents to the screen:
cat file.log
I know how to edit the file, ...
- 15.2k
511
votes
9
answers
816k
views
Can I delete 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.
Can I delete these gigabytes of data without consequences? Are they ...
- 5,480