One or a set of directives issued in the *nix environment to get information, change the state of something or to execute something. In other words: To gain an objective.
Questions tagged [command]
1047 questions
23
votes
2 answers
What does yes $(yes yes) do?
Wondering what use the yes command might be, I stumbled upon this comment, and tried to execute
yes $(yes yes)
From what I understand, this should simply print out an infinite sequence of yes, but instead it outputs nothing and crashes my graphical…
heinrich5991
- 627
9
votes
1 answer
clear full-screen in script and get the previous prompts after exiting script
Today I was using glance tool in my office to monitor CPU utilization.When I run glance from terminal ,the command clears the screen and after all the work when I quit back to the terminal,the previous prompts are still there on my screen.I mean…
g4ur4v
- 1,764
- 8
- 29
- 34
9
votes
1 answer
-bash: python: command not found after install python3 on centos 6
when i finish install python3 , i can use python2, and python3 command ,but when i try python , it says command not found ,here is some output
[root@localhost bin]# python2
Python 2.7.5 (default, Apr 11 2018, 07:36:10)
[GCC 4.8.5 20150623 (Red Hat…
ethan
- 93
6
votes
1 answer
What exactly are commands? How to identify?
I want to know what exactly are Linux commands? & how to identify and locate them?
In other words what are different kind/type/category of commands? How to identify them and locate (source) it.
Pandya
- 24,618
5
votes
5 answers
what is the location of custom commands
where can I find the description/details of the custom commands. In my linux server there is a custom command named qsubm that I need to check, but I don't know where it is written.
Zunaid
- 51
4
votes
5 answers
unix command to print till 3rd occurence of "/" in each line
I have one file contains data as…
Lingaraj R M
- 141
3
votes
1 answer
Block/prevent command if it has been executed within the last x seconds/minutes
(Just for completion: the story; you don't need to read this if you do not want to know why I am asking this question: I got a webcam demon-application (called "motion") with camera motion detection. This demon is able to trigger a custom command…
serjoscha
- 133
3
votes
1 answer
Deference between command "sudo su ls" vs "sudo ls"
I saw some command such as sudo su ls, and I just wonder what's the deference between sudo ls?
Peco
- 161
- 1
- 2
- 5
3
votes
2 answers
Dividing numbers in the same cells between two "Comma-separated values csv" files
I have two Comma-separated values (csv) files. Each file has 1000 columns and 1000 rows ( i.e. every csv file form a matrix 1000x1000)
The values for every cell in the first csv file represent the mean.
The values for every cell in the second csv…
user88036
2
votes
1 answer
Go to the directory where the executable command lives
This is a command-line trick from a book-"The Productive Programmer":
pushd `which java`/..
The author says this command can temporarily go the directory where the executable command java lives.
When I typed this command in Linux, Bash complained…
Feng Yu
- 175
2
votes
1 answer
What does the parenthesis mean in a command description like "mklost+found(8)"
When googling for linux commands, I often see a number in parenthesis like this:
mklost+found(8)
What does it mean?
Is it a version number of the program, reference to some standard, or what?
Nick The Swede
- 123
1
vote
1 answer
Linux Red Hat Library Dependencies question
I have to create a script that will download 8 libraries. However, on the server where we have all the libraries, I can only find 2 or 3 of these 8.
I believe these 2 or 3 actually depend on other libraries to work, so when I request via yum to…
Guillaume F.
- 11
- 1
1
vote
1 answer
What do you mean by low-level commands and high-level commands?
I have read that the difference between useradd and adduser is that useradd is a low-level command and adduser is a high-level command, likewise the difference between netstat and ss is also that ss is low-level command while netstat is high-level…
GypsyCosmonaut
- 4,119
1
vote
1 answer
File name wildcard
I understand . means current directory, and * means any string. My question is the following 2 commands have the same result? I would appeciate your help.
chown -R joe:staff .
chown -R joe:staff *
ngungo
- 141
1
vote
1 answer
How to create a new command and how to view the code for commands
I don't exactly know the difference between a script and a few pages mention that there is almost no difference between them but I do wonder why to execute a command all we need to do is type its name and press enter but to execute a script a .sh…
private ryan
- 21