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1500 questions
96
votes
1 answer
How to change primary group?
I have a user like this:
uid=501(ironsand) gid=500(foo) groups=500(foo),10(wheel),497(git),501(ironsand)
And to change primary group to ironsand like gid=501(ironsand), I typed this command:
sudo usermod -g ironsand ironsand
It changed groups…
ironsand
- 5,205
96
votes
10 answers
Use system clipboard in vi-copy mode in tmux
I'm running tmux 1.6 and I'm trying to configure it to use vi-style keybindings as well as use the system clipboard when copying in interactive mode:
set-window-option -g mode-keys vi
bind-key -t vi-copy 'v' begin-selection
bind-key -t vi-copy 'y'…
Naftuli Kay
- 39,676
96
votes
15 answers
chroot: failed to run command ‘/bin/bash’: No such file or directory
When I run the chroot command an error is given:
failed to run command ‘/bin/bash’: No such file or directory
USER3254789
- 1,091
96
votes
14 answers
How to remove all the files in a directory?
I am trying to remove all files and subdirectories in a directory. I used rm -r to remove all files, but I want to remove all files and subdirectories, excluding the top directory itself.
For example, I have a top directory like images. It contains…
whiterose
- 1,069
- 1
- 8
- 4
96
votes
13 answers
bash: test if $WORD is in set
I am looking for a construct in bash, to decide if a variable $WORD is one of defined words. I need something like this:
if "$WORD" in dog cat horse ; then
echo yes
else
echo no
fi
does bash have such construct? If not, what would be the…
Martin Vegter
- 358
- 75
- 236
- 411
96
votes
4 answers
Why use install rather than cp and mkdir?
I've seen in many places used install -d to create directories and install -c to copy a file. Why not use mkdir and cp? Is there an advantage in using install?
Neaţu Ovidiu Gabriel
- 1,099
96
votes
3 answers
Why is the root directory denoted by a / sign?
I have done some research about this on Google, but the results were cloudy. Why is the / sign used to denote the root directory. Are there any solid reasons behind it?
Ruban Savvy
- 8,659
95
votes
9 answers
Is there a tool that combines zcat and cat transparently?
When handling log files, some end up as gzipped files thanks to logrotate and others not. So when you try something like this:
$ zcat *
you end up with a command line like zcat xyz.log xyz.log.1 xyz.log.2.gz xyz.log.3.gz and then with:
gzip:…
0xC0000022L
- 16,593
95
votes
5 answers
Splitting string by the first occurrence of a delimiter
I have a string in the next format
id;some text here with possible ; inside
and want to split it to 2 strings by first occurrence of the ;. So, it should be: id and some text here with possible ; inside
I know how to split the string (for instance,…
gakhov
- 1,105
95
votes
2 answers
How to display the Linux kernel command line parameters given for the current boot?
In the grub.conf configuration file I can specify command line parameters that the kernel will use, i.e.:
kernel /boot/kernel-3-2-1-gentoo root=/dev/sda1 vga=791
After booting a given kernel, is there a way to display the command line parameters…
colemik
- 1,371
95
votes
2 answers
How to insert text into a root-owned file using sudo?
Possible Duplicate:
Redirecting stdout to a file you don't have write permission on
Running a command like sudo echo 'text' >> /file.txt fails with:
bash: /file.txt: Permission denied
tshepang
- 65,642
95
votes
8 answers
Multiple arguments in shebang
I am wondering whether there is a general way of passing multiple options to an executable via the shebang line (#!).
I use NixOS, and the first part of the shebang in any script I write is usually /usr/bin/env. The problem I encounter then is that…
Rastapopoulos
- 1,669
95
votes
7 answers
How to set custom resolution using xrandr when the resolution is not available in 'Display Settings'
I'm a new Linux user trying to change the screen resolution as there is no option under display. I have successfully managed to add new resolutions by fluke by following online guide. I don't have a GPU, I don't know if this is the issue? Below is…
nick
- 961
95
votes
2 answers
Is there ever a good reason to run sudo su?
To launch a root shell on machines where the root account is disabled, you can run one of:
sudo -i : run an interactive login shell (reads /root/.bashrc and /root/.profile)
sudo -s : run a non-login interactive shell (reads /root/.bashrc)
In the…
terdon
- 242,166
95
votes
4 answers
How to get last N commands from history?
I want to see what are the last N commands in my history. I thought history | tail -n 5 would make it, but I noticed that a multiline command counts for as many lines as it has.
$ echo "hello
how are you"
$ history | tail -2
how are you"
1051 …
fedorqui
- 7,861
- 7
- 36
- 74