Questions tagged [command-line]
This tag is for questions that are about using the command-line interface (CLI), including the use of standard command-line tools and shell commands. However, for questions that are specific to each shell (like Bash, ZSH etc.), use the tag of that particular shell as well.
22,919
questions
2208
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9
answers
8.0m
views
How to unzip a zip file from the Terminal?
Just downloaded a .zip file from the internet. I want to use the terminal to unzip the file. What is the correct way to do this?
- 22.3k
1468
votes
12
answers
4.5m
views
How do I install a .deb file via the command line?
How do I install a .deb file via the command line?
- 26.8k
1399
votes
11
answers
4.0m
views
How do I save terminal output to a file?
How do I save the output of a command to a file?
Is there a way without using any software? I would like to know how.
- 14.3k
1329
votes
8
answers
4.0m
views
How can I copy the contents of a folder to another folder in a different directory using terminal?
I am trying to copy the contents of a folder to another folder in a different directory using terminal.
Would somebody be able to provide me an example of the command line syntax required to achieve ...
- 13.5k
1173
votes
14
answers
1.8m
views
How do I determine the total size of a directory (folder) from the command line?
Is there a simple command to display the total aggregate size (disk usage) of all files in a directory (folder)?
I have tried these, and they don't do what I want:
ls -l, which only displays the ...
- 11.8k
1088
votes
10
answers
3.7m
views
Is there a command to list all users? Also to add, delete, modify users, in the terminal?
I need a command to list all users as well as commands to add, delete and modify users from terminal - any commands that could help in administrating user accounts easily by terminal.
979
votes
7
answers
3.4m
views
How can I add a user as a new sudoer using the command line?
After I add a user using adduser, I can't see it via System > Administration > Users and Groups unless I log out and then log in again. Is that normal?
Also, can I set a newly added user as a sudoer ...
- 11.1k
966
votes
5
answers
2.8m
views
How do I shut down or reboot from a terminal?
How can I shut down or reboot Ubuntu using terminal commands?
- 103k
932
votes
8
answers
2.0m
views
Find and replace text within a file using commands
How can I find and replace specific words in a text file using command line?
- 11.5k
909
votes
9
answers
1.1m
views
How can I recursively delete all files of a specific extension in the current directory?
How do I safely delete all files with a specific extension (e.g. .bak) from current directory and all subfolders using one command-line? Simply, I'm afraid to use rm since I used it wrong once and now ...
- 9,093
884
votes
9
answers
2.3m
views
How do I search for available packages from the command-line?
I have successfully installed some packages using the command:
sudo apt-get install packagename
when I have known in advance that those packages are available. But how can I search for or get a list ...
- 8,975
883
votes
9
answers
2.7m
views
How to install updates via command line?
When I log into my web server via SSH I see the information:
88 packages can be updated.
80 updates are security updates
I tried apt-get update then apt-get upgrade but each time I log in I still ...
- 8,984
805
votes
7
answers
3.0m
views
How do I rename a directory via the command line?
I have got the directory /home/user/oldname and I want to rename it to /home/user/newname. How can I do this in a terminal?
- 18.3k
789
votes
4
answers
4.2m
views
How to delete a non-empty directory in Terminal?
How do I delete the following directory?
I typed:
rmdir lampp
This error comes up:
rmdir: failed to remove `lampp': Directory not empty
Is there a command to delete all the files in the directory ...
- 8,117
769
votes
9
answers
3.8m
views
Change folder permissions and ownership
I would like the user to have full rights on this folder (as well as all sub-directories and files in it):
~/.blabla
currently owned by root.
I have found numerous posts (in this forum and ...
- 14.5k
750
votes
9
answers
2.0m
views
What is the correct way to completely remove an application?
I've searched the net for such information and found different command lines, like these ones:
sudo apt-get remove application
sudo apt-get remove application*
sudo apt-get remove --purge ...
- 7,943
742
votes
16
answers
1.7m
views
How to check Internet Speed via Terminal?
Instead of going to sites like speedtest.net, I want to check my current Internet speed from the terminal on Ubuntu. How can I do it?
- 11.8k
704
votes
9
answers
2.1m
views
What does "sudo apt-get update" do?
I am wondering what sudo apt-get update does?
What does it update?
- 11k
670
votes
8
answers
1.5m
views
How can I decode a base64 string from the command line?
I would like to write a bash script to decode a base64 string. For example I type decode QWxhZGRpbjpvcGVuIHNlc2FtZQ== and it prints Aladdin:open sesame and returns to the prompt.
So far I have tried ...
- 21.1k
654
votes
9
answers
830k
views
How do I check which shell I am using?
I read that terminal is nothing but shell, and Unix provides different flavors of shells:
Bourne shell (sh)
C shell (csh)
TC shell (tcsh)
Korn shell (ksh)
Bourne Again shell (bash)
Questions:
When ...
- 6,715
634
votes
2
answers
1.3m
views
How to redirect stderr to a file [duplicate]
While using nohup to put a command to run in background some of content appear in terminal.
cp: error reading ‘/mnt/tt/file.txt’: Input/output error
cp: failed to extend ‘/mnt/tt/file.txt’: Input/...
- 7,244
612
votes
7
answers
512k
views
Which one is better: using ; or && to execute multiple commands in one line?
In tutorials and how-to's I often see commands combined. For instance,
sudo apt-get update && sudo apt-get install pyrenamer
There seem to be four possible connectors: &, &&, || ...
- 28.8k
600
votes
20
answers
1.2m
views
How do I fix my locale issue?
I am getting this message every time I do something like starting or stopping a service.
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
...
- 6,776
598
votes
25
answers
1.1m
views
How to show the transfer progress and speed when copying files with cp?
Otherwise, is there any alternative command line utility that can achieve this?
- 59.1k
594
votes
4
answers
1.2m
views
How do I check the version of Ubuntu I am running? [duplicate]
How can I check my current Ubuntu version through the command-line and GUI?
- 5,965
582
votes
3
answers
1.6m
views
How do I use variables in a sed command?
I tried the following code to replace QQ with ZZ, but it doesn't do what I want:
var1=QQ
sed -i 's/$var1/ZZ/g' $file
However, this code does what I want:
sed -i 's/QQ/ZZ/g' $file
How do I use ...
- 17.7k
577
votes
2
answers
737k
views
How do I retrieve the public key from a SSH private key?
A SSH private key as generated by ssh-keygen contains a public key part. How do I retrieve this public key from the private key? I've lost my public key and need to put the contents of this public key ...
- 175k
556
votes
6
answers
419k
views
How to see the command attached to a bash alias?
Suppose I have an alias in the bash shell. Is there a simple command to print out what command the alias will run?
- 5,819
546
votes
11
answers
887k
views
How to list all variables names and their current values?
How to list all variables names and their current values?
Including not only $HOME, $PWD etc but any other you have defined.
- 12k
539
votes
13
answers
1.1m
views
Execute sudo without Password?
Inspired by this question....
I am the sole person using my system with 12.04.
Every time I issue a sudo command; the system asks for the user password (which is good in its own way).
However I was ...
- 11.1k
538
votes
12
answers
909k
views
How to really clear the terminal?
I can issue the clear command or press Ctrl + L to clear the current Ubuntu terminal, but this just shifts previous output upwards and if you use mouse scroll or PgUP and PgDown keys it's hard to ...
- 15.2k
513
votes
7
answers
522k
views
How can I get octal file permissions from command line?
There is a chmod command to set file permissions, but can I get file permissions in octal mode (such as 755) from the command line?
- 76.9k
507
votes
17
answers
4.4m
views
How do I run .sh scripts?
Whenever I open a .sh file, it opens it in gedit instead of the terminal. I can't find any option similar to Right Click → Open With → Other Application... → Terminal.
How do I open this file in the ...
- 5,071
502
votes
8
answers
1.6m
views
How to create a bootable Ubuntu USB flash drive from terminal?
Is there any way to create a bootable Ubuntu USB flash drive from the terminal without using any third-party applications like YUMI, Unetbootin, Startup Disk Creator, etc.
I tried to create a ...
498
votes
10
answers
1.1m
views
How to select video quality from youtube-dl?
I have installed youtube-dl in my 14.04.
I can download video by following command,
$ youtube-dl [youtube-link]
But I want to know how to select available pixel quality of youtube video(i.e 1080p, ...
- 11.4k
498
votes
14
answers
726k
views
How can I suspend/hibernate from command line?
How can I suspend or hibernate my laptop using command line, without installing additional software?
- 4,983
491
votes
12
answers
1.8m
views
How to use "grep" command to find text including subdirectories
I want to find all files which contain a specific string of text. The grep command works, but I don't know how to use it for every directory (I can only do it for my current directory). I tried ...
- 8,395
491
votes
5
answers
1.1m
views
What do the different colors mean in ls?
What do the different colours in Ubuntu's ls command mean? For example, when I type the ls command in one of my folders, I get one of the files in light green, the other (which is a folder) in blue ...
- 5,447
486
votes
2
answers
386k
views
Differences between /bin, /sbin, /usr/bin, /usr/sbin, /usr/local/bin, /usr/local/sbin
I have six directories with command files. These are /bin, /sbin, /usr/bin, /usr/sbin, /usr/local/bin and /usr/local/sbin.
What are the differences between these? If I'm writing my own scripts, where ...
user125111
465
votes
12
answers
2.0m
views
How do I move all files from one folder to another using the command line?
I would like to know how could I move all files from a folder to another folder with a command line.
Let's say I'm in my Downloads folder and there are a 100 files that I would like to move to my ...
- 4,651
460
votes
9
answers
1.9m
views
How to remove all files from a directory?
The closest I've gotten is
# rm /path/to/directory/*.*
but that doesn't work for files that don't have an extension...
- 11.1k
455
votes
19
answers
699k
views
How do I check the battery's status via the terminal?
I would like a command that displays the battery status in the terminal.
- 4,551
449
votes
4
answers
1.9m
views
How to make a file (e.g. a .sh script) executable, so it can be run from a terminal
I have a script.sh file and type of this file is shellscript file. I want to make this file as application/x-executable file. How can I make it?
- 7,369
433
votes
10
answers
464k
views
Convert a directory of JPEG files to a single PDF document
I have many JPEG files in a directory, and I want to convert them to PDF and concatenate them together to make a single document.
How can this be done?
I would prefer using the command line, as ...
- 4,481
427
votes
7
answers
958k
views
How to download an MP3 track from a YouTube video
There are several Q&A threads that explain how to download youtube videos using the terminal.
However, I would also like to learn how to extract the video's soundtracks as MP3 files--also using ...
- 5,327
407
votes
11
answers
811k
views
How can I view the contents of tar.gz file without extracting from the command-line?
I want to see the contents (list of files and folders) of an archive, for example a tar.gz file without extracting it.
Are there any methods for doing that?
- 79k
407
votes
5
answers
738k
views
What does 2>/dev/null mean?
I would like a brief explanation of the following command line:
grep -i 'abc' content 2>/dev/null
- 4,835
404
votes
10
answers
453k
views
How can I install just security updates from the command line?
sudo apt-get upgrade installs all updates, not just security updates. I know that I can use Update Manager to select only important security updates, but is there a way to do this from the command ...
- 32.1k
404
votes
6
answers
1.6m
views
How to download a file from a website via terminal?
Suppose that we have a full URL of desired file e.g.
http://domain.com/directory/4?action=AttachFile&do=view&target=file.tgz
I would like to go without installing a new software. Is it ...
- 4,143
401
votes
14
answers
1.4m
views
Command line to list DNS servers used by my system
Is there a command to list DNS servers used by my system?
I tried
$ cat /etc/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY ...
- 4,174