New answers tagged linux
0
votes
How to make Linux stop sending IPv6 ICMP redirects?
Block the redirect packets in ip6tables
sudo ip6tables -I OUTPUT -p icmpv6 --icmpv6-type redirect -j DROP
- 101
0
votes
Building .deb package for Linux perf?
You can use these patches and apply them to the vanilla linux kernel. These patches are more recent than what was posted above. This will build linux-tools-*.deb packages. I've recently tested on the ...
- 101
2
votes
Accepted
After SSH login linux output a kernel version
Option 1:
Add the following in /etc/ssh/sshd_config
Banner /etc/banner
or
Banner /folder/mybannerfile
Write the message you want in the file and restart sshd
Option 2:
It seems it is possible to ...
- 2,128
0
votes
How to identify one of several Firefox installations (location) by id from `~/.mozilla/firefox/installs.ini`?
To get the current firefox profile folder, just type this:
awk -F= '{if(NF){if($1=="Path")path=$2;if($1=="Default")def=$2}else{if(def==1){print "~/.mozilla/firefox/"path;...
- 11
0
votes
Any foss apps on Linux that contain the print booklet feature of Adobe Acrobat Reader?
You can run pdfbook2 (package texlive-extra-utils) on the PDF file.
pdfbook2 - Create print-ready PDF files from some INPUT PDF files for booklet
printing. The resulting files need to be printed in ...
- 11.2k
0
votes
Remove internet access without losing LAN
If all of the nodes, including the master, are on the the same subnet 192.168.1.x/24 then they can communicate directly without any need for a gateway. Only nodes that need Internet access need a ...
- 101k
1
vote
Umask set weird result for files when apply value 0666
umask created some confusion, so after reading some documentation I got a clear idea.
umask: [ u => User ]
When we create files or directories, those files got some default permission.
mask work ...
0
votes
Get user's login duration time without time of locked screen
It's not exactly what you're asking for, but you might find the GNU accounting utilities (acct) useful.
GNU Accounting Utilities is a set of utilities which reports and summarizes
data about user ...
- 73.7k
0
votes
Get user's login duration time without time of locked screen
As far as I knows, the idle time displayed by who command differs from the time with unlocked screen.
No. who is a program that predates graphical sessions. It has no notion at all what a "...
- 15.5k
1
vote
Extracting columns with similar name from two different csv files
Assuming the header in both files is a simple list of comma-delimited field names, without any special CSV quoting, we may extract the field names on separate lines from a file using
head -n 1 file | ...
- 311k
0
votes
Extracting columns with similar name from two different csv files
Using Raku (formerly known as Perl_6)
raku -MText::CSV -e ' \
#read headers of each csv, match column names on first word;
my $csvA = Text::CSV.new; my $csvB = Text::CSV.new;
my $fhA =...
- 1,953
2
votes
"hostname: Name or service not known" when hostname is written in /etc/hosts and /etc/hostname
grep: /etc/nsswitch.conf: Structure needs cleaning
This indicates your root filesystem probably needs a filesystem check: it might be corrupted. And because it's your root filesystem, it is likely ...
- 80k
1
vote
Umask set weird result for files when apply value 0666
umask is a mask, applied to file permissions. touch creates files with permission 666 by default; with a mask of 0666, all those permission bits are masked, so you end up with files with no permission ...
- 393k
0
votes
Primary vs secondary groups in Linux
Primary Group: Used to decide which files are created by which users. One user must belong to only one group.
Supplementary Group: Specifies one or more groups for users to share files between them. ...
1
vote
Accepted
Using IPC_CREAT with an already created shared memory segment
Yes, that's the idea. You use IPC_CREAT to allow the creation, not to force it. To force creation (and failure if the key already exists), IPC_CREAT | IPC_EXCL.
- 15.5k
0
votes
i3 status bar with ANSI *input*
Here is an answer using the third method. It transform a terminal window in a dock by setting the X11 properties understood by i3. It does only work with terminal emulator that does NOT fork their ...
- 111
0
votes
No linux will boot after BIOS update
It works now! I updated my Gigabyte Z590 Vision D to firmware F8f, running Ubuntu 22.04.2 with Linux 5.19; all good now!
- 101
0
votes
HTML symbols using shell
The ⇨ character (U+21E8, RIGHTWARDS WHITE ARROW, ⇨) looks closer to what you want.
🢧 (U+1F8A7, RIGHTWARDS LEFT-SHADED WHITE ARROW, 🢧) even closer.
Your ➡ is the U+...
- 504k
0
votes
Debian one interfaces gets two ip addresses
I just figured out a solution and will share a theory about what I think was happening.
On my system, at least, it looks like the interface is assigned connections from NetworkManager and /etc/network/...
- 1
1
vote
Why cannot I set the date of my GNU/Linux machines to the Epoch?
I would like to elaborate a bit the cases of which this question apply to.
It is not only that you cant date -s '@0', but in fact, you can't do date -s '@X' where X satisfies X<...
- 121
0
votes
How can I join mp4 files in Linux without transcoding the files?
Write mp4 videos paths into file input.txt:
file '/path/to/video1.mp4'
file '/path/to/video2.mp4'
and then run this:
ffmpeg -f concat -safe 0 -i ./input.txt -c:v copy output.mp4
Just this!
- 327
1
vote
How to set a label and UUID for the entire drive?
Only if you format the entire drive as a filesystem as opposed to creating a partition table such as MS-DOS or GPT, you'll get a UUID.
The UUID lsblk reads is from partitions/filesystems.
- 24.1k
1
vote
How to disable root permission on terminal (manjaro)
While it would be possible for an outsider or malware to cause your mouse to move randomly, unless someone is hacking your system just to get your attention, or you have enabled screen sharing (such ...
- 5,081
2
votes
Does running exec command preserves environment variables of the calling shell? If so, why?
Unix doesn't use spawn, it uses fork. Fork clones a process (with a very short list of differences in the child), typically immediately before an exec.
(As said in comment..) The exec system call is ...
- 5,081
0
votes
How to disable root permission on terminal (manjaro)
If you feel someone takes control from outside, the best thing is to install ufw and type:
sudo ufw default deny incoming
sudo ufw enable
Sudo will permit a logged user which is in your sudoers group ...
- 1,484
0
votes
Allow all users full read/write access to CIFS share with automount/autofs
Change your /etc/auto.htpc to:
htpc -fstype=cifs,rw,file_mode=0777,dir_mode=0777,username=content,password=content ://192.168.0.2/Content
That will allow any user to write and read from the ...
- 181
0
votes
How to remove all default gateways
It solves
https://github.com/hub4ops/vagrant/blob/main/Vagrantfile
Vagrant.configure("2") do |config|
config.vm.box = "ubuntu/trusty64"
config.vm.network "...
- 1
0
votes
Free Up Port 53 on Ubuntu so costom DNS server can use it
As was given in another answer, you can mostly follow the tutorial here: https://www.linuxuprising.com/2020/07/ubuntu-how-to-free-up-port-53-used-by.html. I won't rehash those specifics, but if that ...
- 101
1
vote
Error occurred in mounting file system during Linux bootup with busybox
With the testing suggested by Artem, I found out the root cause of the error and how to fix it.
When busybox is started as init process in the system, it first checks /etc/fstab and tries to mount ...
- 161
6
votes
Accepted
User friendly way to apply BadRAM patterns
Something like memmap=1M!2399M will reserve a slice of memory from 0x95f00000 to 0x95ffffff and should do the job. We can surely be finer with the K unit : memmap=32K!2457344K (from 0x95fc0000 to ...
- 1,484
1
vote
Accepted
Direct output from gnome-terminal to text file
Correct Answer
It's very likely you don't need to use gnome-terminal to achieve whatever you're doing. There most likely is a better way to capture the output of ./program than running it in gnome-...
- 19.3k
-1
votes
Zsh script to recursively unrar into a folder with the same name
Did you try the unrar itself?
unrar x archive.rar
If the archive has directories and subdirectories - they would be recreated.
- 4,010
2
votes
Trying to sed a file
Using sed:
$ sed -E 's/.*/Echo &;ssh & date/' file
Echo Computer1;ssh Computer1 date
Echo Computer2;ssh Computer2 date
Echo Computer3;ssh Computer3 date
or
$ sed 's/.*/Echo &;ssh & ...
- 29.1k
0
votes
how to restrict SSH for specific user from specific subnet
Yes - it's in the manual:
AllowUsers
This keyword can be followed by a list of user name
patterns, separated by spaces. If specified, login is
allowed only for ...
- 4,683
0
votes
Accepted
Using awk to pull multiple rows from a txt file and put it a single cell in html
This might be what you're trying to do, using any awk:
$ cat tst.sh
#!/usr/bin/env bash
tmpfile='test.html'
input='test.txt'
awk '
BEGIN {
print "<table border=1 cellspacing=0 ...
- 27.2k
0
votes
Renaming: Remove last X characters from files in directory
Thunar bulk rename tool (thunar -B).
KRename cannot do this. There is a sort of incomplete fork of Thunar's renamer, made for KDE, but which can be used separately, called "Bionic Batch Renamer&...
- 1,224
1
vote
Cron Job to execute every 14 days (or every other Tuesday)
The cron schedule for running a job at 05:15 on Tuesdays is
15 5 * * 2
or use the day name (this may not be supported everywhere),
15 5 * * tue
The easiest way to get your command to run every ...
- 311k
0
votes
How to print full path of a folder which is not current directory?
You can also use find to achieve that. realpath may not exist on all the systems.
find $(pwd) -name "FILE_or_DIR_NAME"
Example:
$ cd ~
$ find $(pwd) -name "reports"
/home/tommy/...
- 272
1
vote
Accepted
packets are filtered via bridge using namespaced network card
I'll limit my references to IPv4 (IPv6 or ARP are also affected, but IPv6 isn't used by OP and no default firewall for ARP exists).
Docker relies on and loads the kernel module br_netfilter for proper ...
- 28.4k
2
votes
Accepted
How to print full path of a folder which is not current directory?
I found the command.
It can be done using realpath.
>/media/hardDrive/Music/ $ realpath Album_1
/media/hardDrive/Music/Album_1
- 21
18
votes
Accepted
Does Bourne Shell have a regex validator?
No, but with some tools it's not hard to test whether a regex compiles or not.
For example, with grep: echo | grep -P '[' - the exit code, $?, will be 2, indicating an error occurred (and for this ...
- 73.7k
0
votes
'Secure Boot dbx Configuration Update' prompt on gui but terminal says everything is up to date. What is it? Is it safe to install?
Leave it to microsoft to screw up my Dell Ubuntu system. I presume this is only for dual boot windows machines? Why would a Microsoft boot loader be on my Ubuntu machine (it is a dell factory-...
- 1
0
votes
Command line to return to the GUI after Ctrl-Alt-F1?
Here's the English version of what the other answers said:
First, log in if it asks you to do so.
Then, run the w command. It will give you a tty# for your desktop GUI.
Then, either press F# or run ...
- 111
-1
votes
Using awk to pull multiple rows from a txt file and put it a single cell in html
The awk ORS (output record separator) variable can be used to combine the output of numerous rows into a single cell. You can modify it to any other string or character; by default, it is set to the ...
0
votes
How to convert APE files to FLAC in Linux?
In the directory with .ape/Monkey Audio files:
dir/with/ape$ for i in *ape; do ffmpeg -i "$i" -compression_level 12 "${i%.ape}.flac"; done
The compression level may be set to ...
- 103
1
vote
Accepted
Shared /opt between distros
Just one:
The /opt is currently used by many commercial (and free) products, which do not like to spread its files over /usr tree. So majority of system administrators would expect to see /opt/oracle, ...
- 4,010
0
votes
How do I jump to the next or previous word with CTRL + arrow keys in a console?
I use zsh, therefore I can enable this behaviour by editing the .zshrc file
The following lines have to be added:
# Enable Ctrl+arrow key bindings for word jumping
bindkey '^[[1;5C' forward-word # ...
0
votes
Automounting LUKS encrypted external usb when device inserted without error or hanging on boot if not present
Just a quick idea...
Maybe use udev to launch script/app which make dir for your mount point and then do all cryptsetup stuff. This script may use key from usb drive.
Try do everything without using ...
- 1
0
votes
How to bind mount from a symlink
With Linux v5.12+ kernels it is possible to create bindmount from symlinks with new mount API. Here is an example:
$ unshare --mount
$ mount --types tmpfs tmpfs /tmp
$ cd /tmp
$ echo TEST1 > test1
$...
- 21
0
votes
How can I configure shutdown, reboot etc. to display a message on an old (2.6) Linux?
Shutdown and so on usually progress through telinit setting the runlevel to 6 or 0, and this calls the kill scripts in /etc/rc6.d/K* so you could add a wall command to one of those scripts in the stop ...
- 47.9k
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