Questions tagged [linux]
A family of Unix-like operating systems using the Linux kernel. If your question is about a certain distribution only, use a more specific tag.
58,794
questions
245
votes
9
answers
857k
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How can I give write-access of a folder to all users in linux?
I installed apache2 on Ubuntu just now, and noticed that the /var/www folder is protected. I can just sudo everything but I would rather just give it write access.
How can I do this?
I tried sudo ...
243
votes
13
answers
319k
views
Batch converting PNG to JPG in linux
Does anyone know a good way to batch-convert a bunch of PNGs into JPGs in linux? (I'm using Ubuntu).
A png2jpg binary that I could just drop into a shell script would be ideal.
241
votes
5
answers
285k
views
Recursively count all the files in a directory [duplicate]
Possible Duplicate:
How can I count the number of folders in a drive using Linux?
I have a really deep directory tree on my Linux box. I would like to count all of the files in that path, ...
238
votes
5
answers
262k
views
What does the asterisk mean after a filename when you type `ls -l`?
I've done an ls -l inside a directory, and my files are displaying like this :
james@nevada:~/development/tools/android-sdk-linux_86/tools$ ll
total 9512
drwxr-xr-x 3 james james 4096 2010-05-07 ...
236
votes
10
answers
471k
views
How to copy symbolic links?
I have directory that contains some symbolic links:
user@host:include$ find .. -type l -ls
4737414 0 lrwxrwxrwx 1 user group 13 Dec 9 13:47 ../k0607-lsi6/camac -> ../../include
4737415 ...
231
votes
11
answers
442k
views
Show keys pressed in Linux [closed]
In Windows there is a program called Keyboard Jedi that shows what keys are pressed on the keyboard.
Is there an equivalent for Linux?
231
votes
3
answers
97k
views
What does the 'rc' in `.bashrc`, etc. mean? [duplicate]
Well, this is embarrassing. I feel like I just realised I don't know a loyal colleague's name after working with them for 10 years. "Hey, er... *cough!*, thanks for that great job you did on setting ...
228
votes
7
answers
304k
views
Allow non-root process to bind to port 80 and 443?
Is it possible to tune a kernel parameter to allow a userland program to bind to port 80 and 443?
The reason I ask is I think its foolish to allow a privileged process to open a socket and listen. ...
225
votes
6
answers
279k
views
How to specify level of compression when using tar -zcvf?
I gzip directories very often at work. What I normally do is
tar -zcvf file.tar.gz /path/to/directory
Is there a way to specify the compression level here? I want to use the best compression ...
221
votes
18
answers
50k
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:
...
220
votes
7
answers
294k
views
Why does Ctrl + V not paste in Bash (Linux shell)?
When I copy something to the clipboard and press Ctrl + V in Bash, nothing happens; However, right clicking and selecting Paste does the job.
Why? Is there any reasonable issue (I'm sure there is) ...
216
votes
9
answers
412k
views
How do I find out what version of Linux I'm running?
Is there a way to determine what version (distribution & kernel version, I suppose) of Linux is running (from the command-line), that works on any Linux system?
216
votes
9
answers
309k
views
How can I find only the executable files under a certain directory in Linux?
How can I find only the executable files under a certain directory in Linux?
212
votes
7
answers
203k
views
scp between two remote hosts from my (third) pc
I have two remote hosts.
host1-> 10.3.0.1
host2-> 10.3.0.2
Both run an ssh server.
The ssh server listens on port 22 in host1 and on port 6969 in host2.
Now, using my local machine, I need to copy ...
210
votes
9
answers
207k
views
How do I configure SSH so it doesn't try all the identity files automatically?
I have been putting my ssh identity files inside my ~/.ssh/ folder. I have probably about 30 files in there.
When I connect to servers, I will specify the identity file to use with something like
...
206
votes
11
answers
40k
views
I accidentally typed password into bash command line
I accidentally typed my password into bash command line, mistaking the Last login: ... line for Wrong password (I was in a hurry). What do I do to cover my trace?
What I did was editing .bash_history ...
198
votes
8
answers
466k
views
How can I create a non-login user?
I'd like to create a user and a group both called subversion on a RHEL 5 system. I looked at the man page for useradd and I guess the command would be just be...
useradd subversion
However, not sure ...
195
votes
4
answers
398k
views
How to install local .deb packages with apt-get
Is there a way to install packages store on your HD with apt-get, like apt-get install ./package.deb?
If not, how to handle the dependencies in a very very easy way?
194
votes
14
answers
863k
views
How do I select all text from a file with nano?
I open a file in Ubuntu nano editor from the comand line and I want to copy all the contents of the file so I can paste it in an another application outside the shell.
So far I can only copy using ...
187
votes
5
answers
90k
views
What's like OSX's pbcopy for Linux
In a terminal in OSX I can pipe output to pbcopy and then go into a web browser and paste it. I tried this in Linux with xcopy but when I switch to the browser it just overwrites the clipboard with ...
184
votes
7
answers
142k
views
How to remove old version of installed snaps
I'm new to snap usage, I have few apps installed on my system, something that I notice when run the command df -h I found mounted different versions of the same snap:
/dev/loop0 143M 143M ...
184
votes
13
answers
550k
views
How do I figure out which /dev is a USB flash drive?
I want to mount a USB drive, two of them and I need two different mount points. Unfortunately, the Linux kernel underwent a name change and I can't figure out which /dev location is the right one. Is ...
179
votes
12
answers
181k
views
Remove a certain line from Bash history file
How can I remove a certain line from history's database?
179
votes
8
answers
266k
views
Obtain kernel config from currently running Linux system?
I accidentally deleted my .config for my kernel configuration on Linux, and seem to remember there was a way to retrieve the kernel configuration via the proc filesystem somehow.
Is this still ...
174
votes
16
answers
356k
views
How to wipe free disk space in Linux?
When a file is deleted, its contents may still be left in the filesystem, unless explicitly overwritten with something else. The wipe command can securely erase files, but does not seem to allow ...
172
votes
16
answers
322k
views
How to check which timezone in Linux?
Is there a way to check which time zone I'm currently in on Linux?
167
votes
9
answers
342k
views
How to install npm in alpine linux
So I can't get to install npm in alpine linux. I thought perhaps I can just do a apk add npm but apparently apk search npm returns nothing, even after a apk update. I'm experimenting with all this ...
166
votes
7
answers
227k
views
No USB devices available in VirtualBox
Oracle VirtualBox is unable to list/filter the USB devices attached to my system. As a result, the guest OS is not able to see any USB device either.
This is my configuration:
Host: VirtualBox 5.0.0 ...
164
votes
16
answers
550k
views
How to check the health of a hard drive
My SATA drive started clicking and I was unable to access the data. This is the hard drive in question:
HITACHI Deskstar T7K250 HDT722525DLA380 (0A31636) 250GB 7200 RPM 8MB Cache SATA 3.0Gb/s 3.5"...
161
votes
6
answers
245k
views
How to retrieve video file information from command line under Linux?
I'd like to see from command line all informations pertaining to a given video file, including length, quality, bitrate, resolution, audio and video formats, number and language of audio streams and ...
159
votes
12
answers
287k
views
Copy entire file system hierarchy from one drive to another
I would like to copy the entire file system hierarchy from one drive to another..i.e contents of each directory as well as regular files in Linux platform. Would be gratefull to know the best way to ...
158
votes
2
answers
309k
views
create tar with multiple directories and file locations
I have some scripts and files located in various locations like:
/etc/dir1
/var/www/html
/home/somedir
I want to make a tar file so that it copies files and folders with the location structure. ...
158
votes
8
answers
294k
views
How can I know the absolute path of a running process?
If I have multiple copies of the same application on the disk, and only one is running, as I can see with ps, how can I know the absolute path to distinguish it from the others?
158
votes
5
answers
202k
views
Finding the process that is using a certain port in Linux
I'd like to be able to find out which process is currently using a certain port in Linux. Is there any way to do this?
157
votes
7
answers
270k
views
How can I tunnel all of my network traffic through SSH?
Whenever I'm using the internet from an insecure location (such as public wifi) I like to use an ssh tunnel (ssh -D port host) to ensure my traffic can't be sniffed. Unfortunately, there seem to be ...
156
votes
9
answers
428k
views
Linux: find out what process is using all the RAM?
Before actually asking, just to be clear: yes, I know about disk cache, and no, it is not my case :) Sorry, for this preamble :)
I'm using CentOS 5. Every application in the system is swapping ...
156
votes
3
answers
187k
views
What does the -p flag do in "mkdir -p"?
What does the -p flag do in mkdir -p?
155
votes
12
answers
260k
views
How can you see the actual hard link by ls?
I run
ln /a/A /b/B
I would like to see at the folder a where the file A points to by ls.
153
votes
4
answers
134k
views
How to wget a file with correct name when redirected?
So after some time of searching on Google and Super User (and scanning man pages) I was unable to find an answer to something that (I think) should be simple:
If you go here:
http://www.vim.org/...
153
votes
3
answers
331k
views
What does /dev/sda in Linux mean?
What does
/dev/sda
stand for? What does it mean?
I have both Fedora and Ubuntu installed and if I explore them using Ext2explore from Windows, I see these names:
/dev/sda6
/dev/sda9
Please ...
148
votes
5
answers
19k
views
How does Linux know that the new password is similar to the previous one?
A few times I tried to change a user password on various Linux machines and when the new password was similar to the old one, the OS complained that they were too similar.
I always wondered, how does ...
148
votes
1
answer
269k
views
How do I unzip a tar gz archive to a specific destination?
I want to unpack a .tar.gz file to a specific directory.
The archive file is in /root/Documents. I want to unzip it into /root/Desktop/folder. The folder structure in zipped file should be preserved ...
147
votes
15
answers
664k
views
Manually closing a port from commandline
I want to close an open port which is in listening mode between my client and server application.
Is there any manual command line option in Linux to close a port?
NOTE: I came to know that "only ...
147
votes
4
answers
237k
views
Display each sub-directory size in a list format using one line command in Bash?
I want to get a list of the directories and their sizes in a list format like how you get when you do a ls -l.
The thing is that is there a one line command that can do this? I see others have long ...
147
votes
1
answer
147k
views
How do I delete all files smaller than a certain size in all subfolders?
I have a folder with many sub-folders containing small tif files (less than 160kb) which have been merged together in bigger pdf files, together with some big multi-page tif files.
I want to delete ...
146
votes
14
answers
444k
views
Remove file without asking
How can I remove a file without asking the user if he agrees to delete the file? I am writing shell script and use rm function, but it asks "remove regular file?" and I really don't need ...
146
votes
12
answers
519k
views
How to check if I have sudo access?
I recently got into trouble because of this.
$sudo vim /etc/motd
[sudo] password for bruce:
bruce is not in the sudoers file. This incident will be reported.
Is there a way to check if I have ...
146
votes
6
answers
242k
views
How to prevent SSH from disconnecting if it's been idle for a while
I have a ssh connection to a machine which gets disconnected by that machine after 30 minutes of no user input. However, if I start something like top, the connection stays alive.
Since this is a ...
145
votes
1
answer
556k
views
Mount device with specific user rights
How can I mount a device with specific user rights on start up? I still have some problems figuring it out. I would like to mount the divide with uid=1000 and gid=1000. My current entry to the /etc/...
144
votes
2
answers
150k
views
What is the difference between yum, apt-get, rpm, ./configure && make install?
I am new to Linux and am running CentOS. I have come across four ways to update or install software.
So far, I've seen:
yum install [program]
apt-get install [program]
rpm -i [program].rpm
wget [...