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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19
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2answers
426 views

Why does niceness range from -20 to 19?

The nice command allows you to adjust the scheduling priority ("niceness") of a program. On all Unix-like systems I've used, niceness is specified by a range of integers, where -20 is the most ...
18
votes
3answers
1k 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 /...
18
votes
2answers
12k views

Is `cal` broken? What happened in September 1752?

If you look at the output of cal 9 1752 you will see this strange output: September 1752 S M Tu W Th F S 1 2 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 The following story ...
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, ...
16
votes
0answers
505 views

How did the system settings directory on UNIX come to be named /etc? [duplicate]

Possible Duplicate: What does etc stand for? And why isn't it named /cnf or /syscf or /cfg? No one I have ever asked has been able to tell me, not that I have access to any of the minds that ...
15
votes
2answers
4k views

What are the main differences between BSD- and linux-based operating systems?

I am a long time linux user and have recently become interested in playing about with BSD-based operating systems. What are the differences between linux and BSD-based systems. I am interested in ...
15
votes
2answers
3k views

Origin of the word cron?

Trying to settle a friendly argument. Is "cron" an acronym for something? Additionally, did it's current canonical name "cron" originate from something shortened for something like chronos or ...
14
votes
2answers
21k views

What is the concept behind “tty” in linux?

Where did the terminology "tty" come from in Linux?
14
votes
4answers
823 views

How was the shift to 64 bits handled on Linux

How was the transition to 64 bits handled on Linux/Unix? The Windows world still seems to have issues with it and I'm curious how it was handled in the *nix world.
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 ...
13
votes
4answers
1k views

How did they manage to drive a Unix computer before mice and copy & paste?

Since Unix is 40 years old, Unix is older than the invention of the computer mouse. (actually only 3 years if Unix is from 1969 and the mouse from 1972) How in the world did a new user do anything ...
12
votes
3answers
713 views

Why do we need the reboot function in different binaries?

Why do we need the reboot function in different binaries? shutdown -r and reboot Or do they differ in something?
12
votes
2answers
752 views

Is there a reason why the first element of a Zsh array is indexed by 1 instead of 0?

From my experience with modern programming and scripting languages, I believe most programmers are generally accustomed to referring to the first element of an array by 0 as index. Are there any ...
12
votes
1answer
172 views

Why is the circumflex/caret character used as a symbol for Ctrl?

I started using the Linux console a long time ago but I never questioned myself about the circumflex aka caret character (^). I'd like to ask why it's used as a replacement for the word Ctrl. I ...
11
votes
3answers
5k views

What is the point of the 'operator' user?

Many un*x systems ship with a user account named 'operator'. What is the purpose of this account? Do some systems actually make use of this account, or is this more of a historical legacy? Have you ...
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 ...
11
votes
1answer
299 views

Why didn't GNU Info succeed man?

As per my knowledge/understanding both help and man came at the same time or have very little time difference between them. Then GNU Info came in and from what I have seen is much more verbose, much ...
11
votes
1answer
588 views

What are the differences in shared memory between early and modern Unix systems?

How could processes share memory in early versions of Unix? How does this compare with modern implementations of shared memory?
11
votes
1answer
1k views

What do all the pictures on the front of the “Unix and Linux System Administration Handbook” represent? [duplicate]

I'm a newcomer to Unix and Linux, and I've been trying to get up to speed on everything. One of the guides I've used is the "Unix and Linux System Administration Handbook" It's a pretty great book, ...
10
votes
3answers
756 views

Why does the “she-bang” begin with a “#!”?

Why does the "she-bang" begin with a #!, like #!/bin/bash? I have always accepted that this how it is done, but is there a reason behind it? Why start with #; isn't that usually a comment? Or is it ...
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 ...
10
votes
4answers
560 views

The future of OpenSolaris

since OpenSolaris is more or less abandoned by Oracle, is there a nice alternative that implements the unique features of OSOL? ZFS is one thing, but I liked the image creation system, that let you ...
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 ...
9
votes
3answers
851 views

Is it true that the first version of Linux was based on parts of Unix? [duplicate]

Me and a friend had a discussion about Linux and Unix today and my friend kept saying that the first version of the Linux kernel was based on [parts] of the Unix kernel. This really surprised me ...
9
votes
3answers
332 views

When was process substitution first introduced?

I'm curios to know how long process substitution has been around. What shell first had it? When did it get added to other shells?
8
votes
2answers
3k views

Why there are only two user defined signals?

In the list of signals defined in a linux system, there are two signals stated as User Defined signals (SIGUSR1 and SIGUSR2). Other signals will be raised or caught in specific situations, but SIGUSRs ...
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) ...
8
votes
1answer
454 views

How were these Linux TCP default settings decided?

I spent quite some time tracking down a problem in production recently, where a database server disappearing would cause a hang of up to 2 hours (long wait for a poll() call in the libpq client ...
8
votes
1answer
504 views

Why is the vi editor's copy command called Yank?

Why is the vi editor's copy command called “yank”? Is there any thing significant that can help me to remember the command name?
8
votes
1answer
342 views

Why does brace expansion range use two dots instead of three (ellipsis)?

I finally understood/discovered why I never got to using bash's (and also zsh's) brace expansion range properly: the syntax is {1..10} instead of what I assumed to be an ellipsis, i.e. {1...10}. May ...
8
votes
2answers
301 views

When was the concept of remote repositories invented?

When were remote repositories, for any package manager, invented and implemented?
7
votes
2answers
473 views

Why are UNIX logins often formed with the first letter of the first name followed by the first seven letters of the name?

I have seen in many places (especially universities) logins formed in the following way: First letter of the first name: John Smithsonian → j First seven letters of the name: John Smithsonian → ...
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 ...
7
votes
2answers
584 views

Unix History: return code octal?

// EDIT: Request to move this question to unix.stackexchange.com I was thrown off guard today by gdb: Program exited with code 0146. gdb prints the return code in octal; looking into why I found: ...
7
votes
1answer
93 views

What is the historical origin of CTRL + P for up and CTRL + N for down?

I am a moderately experienced vim user, who is now beginning to use GNU emacs. At about the same time as I learned that Ctrl-p and Ctrl-n are the default for up and down in emacs, I also learned they ...
7
votes
1answer
450 views

Who are these BSD Unix contributors?

I'm trying to piece together the names of the people who contributed to BSD Unix, according to the contents of the SCCS logs. (This is the version control system used at the time.) A number of names ...
7
votes
1answer
127 views

Why does 8250 UART driver not wake up TTY if more than 256 characters are pending?

What is the motivation of this if-condition in void serial8250_tx_chars(struct uart_8250_port *up)? if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); It has been ...
6
votes
4answers
172 views

Did all of the Requests for Comments directly affect the design of Unix networks?

I want to know more about Linux must be one of my most enduring sentiments. But I often find that I learn the most, or perhaps just feel the most satisfied with what I have learned, when I simply ...
6
votes
3answers
750 views

What's the rationale to have option to use power of 1000 instead of 1024 in df?

I'm curious about df -H and df -h, then man df tells me: -h, --human-readable print sizes in human readable format (e.g., 1K 234M 2G) -H, --si likewise, but use powers of ...
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 ...
6
votes
3answers
555 views

Is `Tru64 UNIX` open source?

Is Tru64 UNIX an open source/free or commercial system? Does it work on 32-bit platform? and what are its features in compare with *BSD & Linux system?
6
votes
3answers
241 views

When were the first graphical app installers created for Linux distributions

Having a discussion at work with a colleague, and he is claiming graphical installers for *nix environments have only been available for the last few years, but I can't find any solid information on ...
6
votes
2answers
375 views

Is there a archive of old man pages? specifically for the features available for grep in early 'ed'

This is just a bit of history rummaging... I'd like to know how different today's grep is to the original implementation, introduced by Ken Thompson in ed. which evolved to ex, which then became vi... ...
6
votes
1answer
450 views

What is ENOANO (No Anode) intended to be used for?

This question is merely for idle curiosity, but I suspect others will be curious as well. Searching through errno.h (of Linux 2.6) I found ENOANO "No Anode". There is no sign of a "No cathode" error. ...
6
votes
3answers
1k views

zsync vs. jigdo

What's the difference between zsync and jigdo? Their core functionality seems the same, so I'm curious on things like performance, file size, and ease-of-use. Would also be interesting to know why one ...
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 "...
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 ...
6
votes
1answer
1k views

What are the origins of rgb.txt?

Where did the list of X11 color names come from? Every resource I've found online claims the origin is unknown, but it must be recorded somewhere. The best information I've found was in an archived ...
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 ...
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 ...