The history of Unix systems and their main components. Please DO NOT USE this tag for shell-related questions; use "command-history" instead.

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29
votes
1answer
3k views

When and how was the double-dash (--) introduced as an end of options delimiter in Unix/Linux?

I don't think the shell/utilities in historical Unix nor in something as "recent" as 4.4BSD supported using a double-dash(or two consecutive hyphens) as an end of options delimiter. With FreeBSD, you ...
3
votes
3answers
158 views

Why is NetworkManager package name upper case?

All other software packages are lower case, so why NetworkManager upper case?
38
votes
5answers
3k views

How to save a command you entered without executing it? [duplicate]

Every Linux user has experienced this annoying thing: you begin typing a long and boring command, then realise you should have executed another one before. How to save the first one to execute it ...
16
votes
2answers
2k views

Who is responsible for the Linux kernel?

As of today, there are many Linux distributions like Ubuntu, Fedora, Gentoo, Mint, Debian, etc. These distributions update at different cycles. Ubuntu seems to update its kernel weekly or monthly, ...
19
votes
1answer
1k views

If chown can change groups, why was chgrp created?

So there's chown which lets you change the owner and group of files and/or directories. But there's also chgrp which only changes the group. Why was chgrp created? Isn't it redundant?
10
votes
3answers
419 views

History of Bash globbing

Is there a historical reason why Bash "globbing" and regular expressions are not identical? For example, I believe that in Bash [1-2]* matches anything that starts with a 1 or a 2 followed by anything ...
2
votes
1answer
91 views

what is the original command to create a file? [closed]

we can create a file by a lot of commands: cat > foo.txt echo 'This is a test' > foo.txt touch foo.txt vi foo.txt (or any text-editor) my questions are: What is the original command to ...
6
votes
2answers
962 views

Why wasn't `creat` called `create`? [duplicate]

Was it just to save typing one letter? I don't think C function names were limited to five characters at the time, as strcmp and unlink are probably just as old. I'm hoping someone who was involved ...
5
votes
2answers
4k views

What does chmod stand for?

In order to memorize a command, it is usually a good idea to learn where it's name comes from. For example, cp comes from copy. usermod means "User Modifiy" (at least I guess so). Where does chmod ...
10
votes
2answers
348 views

Possible to see dead proccesses?

In man ps, it clearly states the different states a process can have on Linux. D Uninterruptible sleep (usually IO) R Running or runnable (on run queue) S Interruptible sleep (waiting for an ...
38
votes
1answer
2k views

What happened to bzip1?

bzip2 had been a de facto standard for quite strong compression throughout many years already. I myself had typed the bzip2 command thousands of times already, which makes me wonder - what happened to ...
3
votes
1answer
102 views

Where can i find any information about ancient doshell(8)?

I check the openvt manual by running "man openvt" command, and i found doshell(8) under "SEE ALSO" section: But there's no manual if i do "man 8 doshell": I checked the online manual at http://...
8
votes
1answer
1k views

Can the 25 years of development of the Linux kernel be qualified or abstracted in layman's terms? [closed]

The Linux kernel is almost 25 years old. If I had to come up with the short version on the development history of the Linux kernel since 1991(its inception date), and in partcular since 1994 (1.0.0) ...
24
votes
1answer
874 views

At what point did the /home directory appear?

Originally in Unix, /usr was used for user (home) directories. So if I had a user named alex, my home directory would be /usr/alex. (Interestingly, Plan 9, the successor to Unix, still has user ...
6
votes
2answers
227 views

What's the story behind command file's suggestion?

While I'm reading file(1) I noticed this in the man page (emphasis mine): When adding local definitions to /etc/magic, make sure to preserve these keywords. Users depend on knowing that all the ...
1
vote
2answers
105 views

Why are user account on remote server called shell account

Why are user accounts on a remote server called shell account , remote account sounds like a more intuitive name what is the reason behind this very unintuitive name ???
6
votes
2answers
345 views

Regex `/pattern/g` and ed `:g/pattern/`: which came first, and why `g`?

The g option (e.g. s/pattern/replacement/g) for many tools that use regex-style pattern matching and the :g command in ed, ex, vi, and vim have pretty similar usage and meaning: match the given regex "...
7
votes
2answers
14k views

What does the “rc” stand for in /etc/rc.d? [duplicate]

Does anybody have an idea about the full form of rc.d in, for example, /etc/rc.d? It contains scripts to used to control the starting, stopping and restarting of daemons. But what exactly is the ...
2
votes
1answer
696 views

Is the Linux implementation of the system configuration “variable” ARG_MAX different from other system variables and is it POSIX compliant?

In the shell, as explained in this this Q&A in the context of expansion, depending on the system, the maximum length of a command's argument is initially constrained by the kernel setup. The ...
2
votes
1answer
382 views

What is “Charlie &” in the gecos field on OpenBSD for root?

Question: what is "Charlie &" for the root user? I didn't gave "Charlie &" for gecos field, I think I didn't gave any at all. ps.: the "/sbin/nologin" doesn't matters, I just tested ...
5
votes
3answers
482 views

Why BitchX is called BitchX?

Well, the title is pretty much self-explanatory, but for sake of completeness, I'm curious to know the reason for the name of BitchX. I searched on internet for etymology but it was a fail. I hope ...
129
votes
4answers
30k views

Why are tar archive formats switching to xz compression to replace bzip2 and what about gzip?

More and more tar archives use the xz format based on LZMA2 for compression instead of the traditional bzip2(bz2) compression. In fact kernel.org made a late "Good-bye bzip2" announcement, 27th Dec. ...
4
votes
1answer
113 views

Is the historical Unix V5 tr command padding behavior of set2 different from what we consider today “classic” System V (1983-1988) behavior?

The tr command is almost 40 years old. It seemingly appeared in Unix for the first time in 1973 with Unix V4. The source for this is not available. Here is probably the second oldest available Unix ...
3
votes
1answer
185 views

When did Automake switch to using Perl

I tried to get remove Perl from my Ubuntu machine, but found that automake not only depends on Perl but itself is a Perl program. I read somewhere this was not always the case. Today I looked in the ...
19
votes
3answers
832 views

Use of ^ as a shell metacharacter

I wrote a small script today which contained grep -q ^local0 /etc/syslog.conf During review, a coworker suggested that ^local0 be quoted because ^ means "pipe" in the Bourne shell. Surprised by ...
4
votes
1answer
355 views

Presentation Tools Back In The Day

Which tools were around »back in the day« to aid presentation Unix/Linux environments? I just wondered how somebody would accomplish something like slides in a e.g. text-based environment or low-end ...
5
votes
4answers
529 views

Does Linux use original Unix code or do they share the idea? [duplicate]

Does the Linux kernel use original Unix code or do they share the idea? He mocked me and said it's a stupid question to ask and of course they share the idea not the code. Since both are written in C, ...
86
votes
3answers
15k views

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?
4
votes
1answer
938 views

What does the “f” in fdisk stand for?

gdisk stands for GPT fdisk. cfdisk stands for curses fdisk. And so on and so forth. However, what does the original "f" in fdisk stand for? The only things I can think of would be either "files" or "...
3
votes
4answers
866 views

How do you find what keys the “erase” and “line-kill” characters are in Ubuntu?

I'm new to Unix and have bought today a copy of "The Unix Programming Environment". I'm trying out the stuff from the book. But some of them are not working as expected like : To kill a line and re-...
3
votes
1answer
3k views

Why does halt not turn the machine off? [duplicate]

shutdown now kills everything and then powers down the machine. halt kills everything and then... there is no step 2. It will sit, running but not doing anything, until people stop arguing over ...
52
votes
5answers
5k views

Why does no one use the true Bourne shell as /bin/sh?

I've noticed that basically no system I've ever worked with has /bin/sh as a real executable. It's always a symlink to dash, bash in POSIX mode, or something similar. Why? What are the disadvantages ...
3
votes
4answers
456 views

Is the Filesystem Hierarchy Standard a UNIX standard or a GNU/Linux standard?

The Filesystem Hierarchy Standard says where to put stuff in a UNIX distribution. Is the FHS used/designed for use outside of GNU/Linux, or is it mostly limited to GNU/Linux?
4
votes
1answer
192 views

Why does System V traditionally symlink /bin to /usr/bin?

This systemd wiki page about the /usr merge, under Myth #6, states that /bin has traditionally been a symlink to /usr/bin on System V UNIX. What is the motivation for this? For backwards ...
5
votes
2answers
246 views

What does it mean when something says that UNIX device files are static?

I've been reading up on udev. In the "overview" section, Wikipedia states that "unlike traditional Unix systems, where the device nodes in the /dev directory have been a static set of files, the Linux ...
14
votes
4answers
1k views

/usr/bin/ptx: Can you provide a use case or two?

I was going through the list of files included in coreutils and I was able to come up with an example of how I could personally use all of the commands provided except for ptx. Can you give one or two ...
190
votes
5answers
34k views

What's the story behind Super Cow Powers?

As we know, apt-get has Super Cow Powers and aptitude does not: $ apt-get --help | grep -i cow This APT has Super Cow Powers. $ aptitude --help | grep -i cow ...
5
votes
1answer
167 views

“globbing” (*) comes from “global command”… Huh?

According to legend, in the early days what we now call "globbing" (i.e. using expressions like e.g. *.c, ./*.p?) was supported by one certain program /etc/glob, whose name in turn derived from "...
1
vote
0answers
61 views

Where does backtick and single quote come from when denoting commands e.g. `prog'? [duplicate]

When referring to commands in tutorials, man pages, and articles I see authors use the backtick and single quote in this way: `./configure' `make' I believe I have seen gcc denote points of failure ...
6
votes
1answer
220 views

Why has the ANSI 3.64 standard been withdrawn?

From the Wikipedia "ANSI escape code" article: The name "ANSI escape sequence" dates from 1981 when ANSI adopted ECMA-48 as the standard ANSI X3.64 (and later, in 1997, withdrew it). Does ...
56
votes
5answers
25k views

What is the purpose of the hash command?

If you run hash it shows the path of all commands run since the hash was last reset (hash -r) [root@c04c ~]# hash hash: hash table empty [root@c04c ~]# whoami root [root@c04c ~]# hash hits ...
11
votes
2answers
14k views

How can you log every command typed

How can you log every command someone has entered into the shell? I'm asking on both the basis of protecting yourself if you are logged into someone else's server and something breaks, or if someone ...
4
votes
2answers
90 views

Why is the default choice for -I argument '{}'?

It seems you can pass in a variable name like 'file' for -I argument of xargs, but there are a plethora of examples that use {}. Is this because of the backward compatibility? Or does it help with the ...
6
votes
1answer
202 views

Where does this convention for quotation marks (`` …'') come from? [closed]

Frequently I get asked the question: ``K., where does this convention for quotation marks come from? You know, the one with the two grave accents introducing a quoted string and two regular ...
161
votes
3answers
11k views

Why not use “which”? What to use then?

When looking for the path to an executable or checking what would happen would you enter a command name in a Unix shell, there's a plethora of different utilities (which, type, command, whence, where, ...
32
votes
1answer
2k views

Were all Unix commands re-written in Linux?

I would like to know which commands were re-written for Linux and which were retained from Unix? I'm new to Linux.
1
vote
1answer
271 views

Who was James Farber and why was he important to Unix?

I've been reading papers on Plan 9 from Bell Labs. In the paper on why Plan 9's not dead yet, around page 18, the author mentions "Farber". Googling reveals this to be a James Farber, but all I can ...
2
votes
2answers
274 views

Is the GNU Coreutils copied from Unix?

Linux itself is not a copy of Unix because one can argue it simply conforms to the POSIX standard. However, how about the GNU Coreutils which contains utilities like ls, cd and rm, etc...? Is there ...
2
votes
1answer
271 views

SSH Authentication Mechanism

Doing a personal research project and I'm wondering: Why does SSH do its own mechanism negotiation rather than use SASL? At first I thought it might be to ensure confidentiality of the whole session, ...
2
votes
3answers
161 views

Why are POSIX Find Parameters Different from Other Program styles?

Why is a parameter in the POSIX find command added with a single hyphen for multi-character parameter names, while most other programs use single hyphen to indicate multiple single-character flags, ...