Questions tagged [terminology]
For questions about words/terms that are specific to Unix and/or Linux.
180
questions
1601
votes
10
answers
522k
views
What is the exact difference between a 'terminal', a 'shell', a 'tty' and a 'console'?
I think these terms almost refer to the same thing, when used loosely:
terminal
shell
tty
console
What exactly does each of these terms refer to?
- 35.3k
248
votes
9
answers
207k
views
What does etc stand for?
What does the "etc" folder in the root directory stand for? I think knowing this will help me remember where certain files are located.
Update: Might be useful for others, the folder is used for "...
- 2,591
161
votes
5
answers
179k
views
What is a Superblock, Inode, Dentry and a File?
From the article Anatomy of the Linux file system by M. Tim Jones, I read that Linux views all the file systems from the perspective of a common set of objects and these objects are superblock, inode, ...
- 9,499
112
votes
2
answers
83k
views
What are the differences between interactive, non-interactive, login, and non-login shells? [duplicate]
Possible Duplicate:
Difference between Login Shell and Non-Login Shell?
I have been looking at /etc/profile and /etc/bash.bashrc
to see how they are run,
and notice that some are executed by non-...
- 7,531
82
votes
6
answers
69k
views
What is a socket?
Could someone explain to me what a socket is? I see it in many acronyms in context of SSL, etc.
Also, why is it called a socket? Is it purely because it was what a name they invented? Or was it the ...
- 8,533
77
votes
6
answers
98k
views
Differences between volume, partition and drive
What do these terms mean exactly?
partition
volume
drive
On Windows, one may say drive C: or partition C:. On Linux I'm not sure what should be used for partitions because they don't have a name.
user44920
76
votes
1
answer
14k
views
Why a "login" shell over a "non-login" shell?
I have a basic understanding of dotfiles in *nix system. But I am still quite confused about this Difference between Login Shell and Non-Login Shell?
A bunch of different answers (including multiple ...
- 985
66
votes
4
answers
54k
views
What is the difference between a job and a process?
What is the difference between a "job" and a "process"?
- 5,319
65
votes
5
answers
11k
views
Why is there a * When There is Mention of Unix Throughout the Internet?
I've noticed that throughout the Internet, within forums and blog posts, Unix always has a * in the word, whether it is *nix or Un*x, as I noticed at the welcoming banner at the Unix StackExchange ...
- 2,187
64
votes
2
answers
174k
views
What is $PWD? (vs current working directory)
So Wikipedia (link) tells me that the command pwd is short for "print working directory", and that makes sense.
But for the environment variable, the "P" has to be an acronym for something else than ...
- 953
61
votes
3
answers
33k
views
understanding "mount" as a concept in the OS [duplicate]
I want to understand what mounting is. It is used in different contexts and situations (directories, flash drives, network cards, etc) and I can't find resources which:
Describe the mount concept;
...
- 5,381
53
votes
2
answers
6k
views
Why do some Linux files have a 'd' suffix?
I observed some of the binary files and configuration filenames end with a d.
What is reason for putting a d at the end of the file name?
Like httpd, ospfd, pppd, syslogd, telnetd, pptpd, inetd, ...
- 637
46
votes
4
answers
37k
views
What is the correct name for the ">" command
I was trying to find how to pass some text to a file without overwriting what's there already using the > command and I realised I don't know what it's called. Searching for right arrow or right ...
- 1,595
46
votes
1
answer
45k
views
Understanding window manager terminology: Mod Keys, Meta Keys, and key naming conventions
In window managers' circles, there are some technical terms; a couple of them are "Mod keys" and "Meta keys." The questions I am asking are:
What exactly are those, and are they ...
- 3,459
41
votes
1
answer
15k
views
What is "firmware" in Linux terminology?
I'm being confused by the use of firmware in the context of Linux.
My understanding of firmware & driver is that firmware is the code that runs on the bare metal of a device such as a Bluetooth ...
- 513
38
votes
1
answer
3k
views
Why does Plan 9 use "snarf" instead of "copy"?
When you watch presentations about Plan 9 and its acme editor you might notice that the name for copy is snarf (I wasn't able to find any meaningful explanation unfortunately).
Why is it so?
Is ...
- 4,773
36
votes
8
answers
8k
views
Why was the word "shell" used to describe a command-line interface?
I'm curious about the term "shell." I think I know what it is (though the distinction between "shell" and "terminal" is still fuzzy) but why was the word "shell" chosen to describe this type of ...
- 4,722
35
votes
5
answers
8k
views
Why do /usr and /tmp directories for Linux miss vowels in their spellings?
I have often started to think about this but never found a good answer. Why are these two Unix directories not /user and /temp instead?
All the other directories under root seem to be exactly what ...
- 35.3k
34
votes
1
answer
4k
views
What is the significance of "tab" e.g. in "crontab" or "inittab"?
What does the "tab" mean in "crontab" or "inittab"?
Having some idea of its meaning might help to mentally categorise files which contain the "tab" suffix and understand their relationship with the ...
- 12.3k
34
votes
6
answers
20k
views
File systems vs partitions vs directories
I am new to Linux so pardon me for the possible confusion you may encounter in this question.
From what I understand, filesystem specifies how a partition stores/manages file, with standards such as ...
- 1,615
32
votes
1
answer
27k
views
What does "LSB" mean when referring to executable files in the output of /bin/file?
I have found the term "LSB executable" or "LSB shared object" in the output of the file command in Linux. For example:
$ file /bin/ls
/bin/ls: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), ...
- 865
30
votes
4
answers
6k
views
What is "horkage"?
There are a lot of constants in the Kernel named with HORKAGE,
ATA_HORKAGE_ZERO_AFTER_TRIM
ATA_HORKAGE_NODMA
ATA_HORKAGE_ATAPI_MOD16_DMA
ATA_HORKAGE_NO_DMA_LOG
ATA_HORKAGE_NO_ID_DEV_LO
...
- 30.9k
30
votes
3
answers
44k
views
Difference between block size and cluster size
I've got a question concerning the block size and cluster size. Regarding to what I have read about that I assume the following:
The block size is the physical size of a block, mostly 512 bytes. ...
- 473
27
votes
5
answers
15k
views
Why is "shebang" called "shebang"?
Does "shebang" mean "bang she"?
Why not "hebang" as "bang he"?
- 102k
27
votes
3
answers
2k
views
How to say 'UN*X or *nix' in conversation or reading aloud? [closed]
Should it be 'star nix' or 'nix' or 'unix-like' or something totally different?
- 2,213
26
votes
4
answers
6k
views
Terminology reconciliation: Display manager vs. session manager, Windowing system vs. Window manager
I am taking the Linux Foundation's Introduction to Linux course. Some of the terminology seems to overlap or contradict, especially when I try to supplement the course material with other sources, ...
- 15.9k
25
votes
2
answers
11k
views
Expansion of a shell variable and effect of glob and split on it
This post actually contains two separate questions but I think grouping them together will give some more context. I have gone through this question on quotes around variables but I do not quite ...
- 6,718
25
votes
1
answer
12k
views
Can an interactive shell become non-interactive or vice versa?
Can an interactive shell become non-interactive or vice versa?
Note: I've done a lot of research on the basic question, "What is the difference between interactive and non-interactive?", and the ...
- 36.5k
24
votes
2
answers
7k
views
command line terminology: what are these parts of a command called?
At the command line I often use "simple" commands like
mv foo/bar baz/bar
but I don't know what to call all the parts of this:
┌1┐ ┌──2───┐
git checkout master
│ └──────3──────┘
└───────4─────────...
- 817
23
votes
1
answer
21k
views
What are X server, display and screen?
From https://unix.stackexchange.com/a/17278/674
If you run ssh -X localhost, you should see that $DISPLAY is
(probably) localhost:10.0. Contrast with :0.0, which is the value
when you're not ...
- 102k
21
votes
3
answers
2k
views
What does "on-line" mean, as used in man(1)?
On my system (Darwin 15.5.0), man(1) opens as follows:
NAME
man - format and display the on-line manual pages
The file the page is formatted from, however, is clearly on disk:
% man -w man
/...
- 313
20
votes
5
answers
11k
views
Some people told me FreeBSD is NOT Unix, is that right? Confused
Some people told me FreeBSD is NOT Unix, is that right? I'm confused.
I checked some articles, but the expressions are pretty vague, and I need some clarification.
- 415
20
votes
2
answers
3k
views
What does “magic tests” mean for the file command?
I was reading about the file command and I came across something I don't quite understand:
file is designed to determine the kind of file being queried.... file
accomplishes this by performing ...
- 902
17
votes
6
answers
18k
views
Drive name? What is the correct term for the "sda" part of "/dev/sda"?
fdisk(8) says:
The device is usually /dev/sda, /dev/sdb or so. A device name refers to the entire disk. Old systems without libata (a library used inside the Linux kernel to support ATA host ...
user6860
17
votes
2
answers
2k
views
Understanding piped commands in Unix/Linux
I have two simple programs: A and B. A would run first, then B gets the “stdout” of A and uses it as its “stdin”. Assume I am using a GNU/Linux operating system and the simplest possible way to do ...
- 273
17
votes
2
answers
20k
views
What are DNS server, resolver and stub resolver?
https://www.freedesktop.org/software/systemd/man/systemd-resolved.service.html#Description says
Additionally, systemd-resolved provides a local DNS stub listener on IP address 127.0.0.53 on the ...
- 102k
14
votes
6
answers
2k
views
What does the name of the unix command apropos mean?
Apropos is a tool to search the headers of the man pages for a string.
What does the name apropos mean?
- 35.3k
13
votes
3
answers
5k
views
Why BitchX is called BitchX?
I'm curious to know the reason for the name of BitchX. I searched on internet for etymology but it was a fail.
- 875
13
votes
1
answer
4k
views
What does 'uni' mean in unistd.h
What does uni mean in unistd.h
Does it mean unix? or universal?
What is it?
- 1,515
12
votes
5
answers
19k
views
What is a "non-option argument"?
I am trying to understand info who but completly fail at the term "non-option argument". Can someone please explain this term to me in simple words or an example?
UPDATE: from info who :
If ...
- 5,040
11
votes
2
answers
3k
views
Why is the Nginx webserver called a "reverse proxy"?
Why is the Nginx webserver called a "reverse proxy"? I know any "proxy" to be a "medium" and this touches a more basic question of "how can a medium be forward or reverse".
user149572
11
votes
4
answers
1k
views
Disambiguating the word "command" in Linux
The word command refers to two different concepts in Linux:
An executable program, such as grep (or a shell built-in, such as cd). Example usage: "Here are the top 10 Linux commands you should ...
- 486
11
votes
2
answers
776
views
What does [[.ch.]] mean in a regex?
Alternate title: What is a "collating sequence" or "collating element" in a POSIX-compliant regex?
I found the exact technical definition in Section 9.3.5 of the POSIX specs, as item #4 in the list, ...
- 36.5k
10
votes
3
answers
10k
views
10
votes
4
answers
61k
views
Command 'date +FORMAT' — What are %a, %A, %b, etc. called?
The date command outputs the current date and time like this: Fri Apr 12 15:04:03 UTC 2013.
To have the output date-time in a custom format we can use date +FORMAT, for example, like this: date "+%Y-%...
- 14k
10
votes
2
answers
22k
views
What does "inet" stand for in the ip utility?
I would assume 'inet' stands for internet ip address, but is that correct? (And 'inet6' being internet ip address v.6.)
ip a yields a list of virtual (and physical?) network devices. When an IP ...
- 6,454
10
votes
2
answers
30k
views
What does “batch mode” mean for the top command?
I was reading about the top command and I came across something I don't quite understand:
top options:
-b Run in batch mode. This is useful for sending output from top to other programs or to ...
- 902
10
votes
2
answers
4k
views
Globbing vs wildcards
What is the difference between globbing and wildcards, are they two terms for the same thing, or are they different?
- 101
10
votes
1
answer
709
views
Confusion regarding the term 'mount' in Linux
I am reading the man page of mount and clone.
I understand that mount is used to add a directory hierarchy to a mount point (a directory).
In clone's man page, under the CLONE_NEWNS section, they ...
- 1,363
9
votes
3
answers
14k
views
In Unix speak what is the difference between a shell script and an executable?
I have seen this question on this site and this prompted me to ask this question . I want to know in Unix speak what is the difference between an executable and a shell script ?
- 6,718