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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Zeller's congruence and cal command

According to Zeller's Congruence, the day of 29 Feb, 1600 is Tuesday. However, the cal command shows it as Friday.Is there a bug in cal's code or a limit on the range of years which Zeller's ...
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5answers
2k views

What is the point of mv -f?

The GNU Coreutils manual for mv says: -f --force Do not prompt the user before removing a destination file. However, this already seems to be the default behaviour for mv, so the -f option appears ...
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3answers
1k views

The Linux kernel: breaking user space

I started thinking about this issue in the context of etiquette on the Linux Kernel Mailing list. As the world's best known and arguably most successful and important free software project, the Linux ...
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0answers
39 views

What is the background of the program segmentation?

Each program is separated into several segments like: code segment data segment stack segment heap segment But who was responsible for that progression? The compiler and linker has to support that ...
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2answers
155 views

Why does xargs -I imply -L 1

I've seen Why does 'find -exec cmd {} +' need to end in '{} +'? which explains why {} + has to be at the end of the -exec cmd(*), and now I'd like to know why GNU xargs reverts to one ...
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1answer
37 views

Etymology of “descriptor” in “file descriptor”

The choice of the word descriptor has always struct me as odd. "Index" or "id" seem like more obvious alternatives. Is there a known rationale for the choosing the word "descriptor"? I guess "...
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1answer
214 views

Where did the default GTK2 theme (raleigh) theme come from?

Who made the theme? When was the theme made? Was it made originally for a specific distro? Does the theme have anything to do with the city of Raleigh?
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2answers
427 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 ...
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3answers
169 views

Historically why is umask the way it is?

umask has always tripped me up. Logically I would prefer to have a 'setmask' instead that takes chmod-style arguments. Anyone know why it is the way it is?
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0answers
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Where does the name of i3 (the WM) come from?

I was thinking about this, so I searched the i3 website, but did not find anything. I was alarmed by the thought, that the name was ie (internet explorer) in leetspeak. It might also be a weird ...
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2answers
4k views

Why is rm allowed to delete a file under ownership of a different user?

From the post Why can rm remove read-only files? I understand that rm just needs write permission on directory to remove the file. But I find it hard to digest the behaviour where we can easily delete ...
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2answers
830 views

Where does the word GNU come from?

GNU is a Unix-like operating system. That means it is a collection of many programs: applications, libraries, developer tools, even games. The development of GNU, started in January 1984, is known ...
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321 views

How can I find out the IP address from which a user logged in?

We have two RHEL 6.4 64-bit boxes in our environment. They are accessed remotely via putty. The password of user ABC on one RHEL box is shared by multiple users. User ABC logged into server from ...
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1answer
124 views

What is the meaning of the mode mask names from stat(2) and chmod(2)?

The stat calls have a series of symbolic names for the various bits in the mode field. From the stat(2) manual page: The following mask values are defined for the file mode component of the st_mode ...
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1answer
4k views

Why is the Intel HD Graphics driver called i915?

The only references to i915 I can find are indeed to the linux kernel driver for the intel chips. Intel just seems to call them HD graphics whatever. Intel 915 seems to refer to some Pentium 4 ...
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2answers
91 views

Why are certain naming conventions so inconsistent in Linux? [closed]

It seems like the general pool of logging, changelog, readme, and config files in Linux is very inconsistently named. It always makes me wonder, why didn't *nix devs decide on a common file name ...
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1answer
458 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 ...
2
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1answer
162 views

Why is vdir still around?

After installing Debian 8, I started poking around /bin (as I'm always wont to do), and I noticed that ls and vdir share, not only the same manpage (except for the whatis line), but the exact same ...
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2answers
3k views

Patching a binary with dd

I have read this quote (below) several times, most recently here, and am continually puzzled at how dd can be used to patch anything let alone a compiler: The Unix system I used at school, 30 ...
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4answers
4k views

Why are UNIX/POSIX system call namings so illegible?

What is the reason to use such untelling system call names like time and creat instead of getCurrentTimeSecs and createFile or, maybe more suitable on Unix get_current_time_secs and create_file. Which ...
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1answer
81 views

Why should you avoid “stringently columnar” input formats?

Doug McIlroy, the inventor of Unix pipes and one of the founders of the Unix tradition, had this to say at the time [McIlroy78]: (ii) Expect the output of every program to become the input to ...
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1answer
297 views

sudo ls not showing hidden files on Linux

Today I discovered that sudo ls shows hidden files (that is, those that have names starting with .) on OS X. This surprised me so much that I asked a question about this behaviour, which I still find ...
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1answer
506 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?
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1answer
135 views

Who was the original author of logrotate and what year was it written?

The question started as an internal team debate. But we realized we couldn't find any information about when the original version of logrotate was authored and who wrote it.Do you have idea?
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1answer
82 views

deleting all occurences of a given command from history [closed]

I am trying to delete a specific entry in history. Clarification--by that I mean deleting all occurences containing a given command/or text. I used Aliteralmind's hxf script: :< Examples hxf ...
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2answers
1k views

Where is “export var=value” not available?

I have picked up -- probably on Usenet in the mid-1990s (!) -- that the construct export var=value is a Bashism, and that the portable expression is var=value export var I have been advocating ...
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1answer
56 views

What are the oldest irc clients I can still use on linux ?

I have a weakness for nostalgia and some interest in Unix history, therefore I would like to know which are the oldest still usable irc clients that can be run on Linux. In this context I value age ...
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1answer
53 views

important changes of linux 3.1 to 3.17 [closed]

I'm doing school research project for Linux operating system and I need help with summary of version 3.1 to 3.17. The problem is, I know very little about Linux and detailed technological terms used ...
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1answer
345 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 ...
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0answers
135 views

how to copy files using TTY teminal from one pc to another connected through same home network

In my academic lab my friend copied files from one computer to another that were serially connected using the tty4. How could he have done this if there was no internet and he didn't install any new ...
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1answer
53 views

Why did “argument can be squished against option” prevail over “argument is always separate”?

Inspired by the recent question Why does the specific sequence of options matter for tar command?, in which the asker learned why tar -cfv test.tar *.jpg doesn't work, I'd like to ask a followup: ...
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1answer
141 views

Did Linux have a bug where reading /dev/null would crash the system?

About 10 years ago I've been told by someone that for years Linux used to crash whenever you tried to read /dev/null (ie. cat /dev/null). Is this actually true? Did such a bug exist? And if it did, ...
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1answer
5k views

Why is the UNIX system call kill named 'kill'?

I'm curious about the history of the name, it seems to me that the 'kill' system call could have been named 'signal', and the 'signal' system call could have been named 'handle'. I was wondering ...
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70 views

Is Cat-v.org an official subsidiary website of Plan 9 from Bell Labs?

I was wondering, since it seems to be one of the only websites where I can seemingly legally download historic Unix documents.
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2answers
98 views

what are considered old and powerfull commands? [closed]

I came across the terms awk and sed, awk goes once through all lines and performs a task whenever a line meets a certain condition, sed can manipulate a stream of input before it goes further to the ...
1
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1answer
315 views

Why has '-' been chosen as the backup file suffix for certain Unix system files?

Example: /etc/group-, /etc/passwd- Is there any motivation behind choice of the - sign (e.g. easier to recognize, process, etc.)?
5
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1answer
292 views

Why does 'find -exec cmd {} +' need to end in '{} +'?

Preface: I understand the difference between -exec {} \; & -exec {} +. I also don't have a problem as such, I am just curious about the semantics of find. When ending the -exec argument with + ...
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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 ...
3
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1answer
93 views

Syntactic differences in cp -r and how to overcome them

Let's say we are in a blank directory. Then, the following commands: mkdir dir1 cp -r dir1 dir2 Yield two (blank) directories, dir1 and dir2, where dir2 has been created as a copy of dir1. ...
3
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1answer
93 views

Has Unix been used by accountants and other non-programmers at AT&T in the 70s and 80s?

In the short documentary, Ken Thompson and Dennis Ritchie Explain UNIX (Bell Labs) it is mentioned, that Unix is not only an OS, but also a system around which a community could form. I find ...
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1answer
856 views

What does “dd” stand for? [duplicate]

What does dd stand for? I've always referred to it colloquially as "Disk Destroyer", but what are the "official" words that make up the acronym/command? According to this link and this link it could ...
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0answers
115 views

The history of ../ [duplicate]

I was wondering if there's a known reason behind the use of .. to represent the parent of the current directory in most operating systems. The reason I ask this question is because I think that the ...
6
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1answer
451 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. ...
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1answer
164 views

Can somebody list the earliest public source-code repositories and when they opened? [closed]

Nowadays people only know github, some people know gitlab, some people know bitbucket (mercurial) but other than that people seem to have forgotten there were others as well. I know about freshmeat ...
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3answers
945 views

How did the Linux Kernel project track bugs in the Early Days?

We all know that Linus Torvalds created Git because of issues with Bitkeeper. What is not known (at least to me) is, how were issues/tickets/bugs tracked up until then? I tried but didn't get anything ...
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0answers
24 views

history - bash, dash, zsh and .profile [duplicate]

For a long time I have been wondering about the existence of many shells in GNU/Linux. To make the question a bit focused I have used only three shells - bash, dash and zsh. From wikipedia articles ...
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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 ...
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1answer
199 views

Use case for /usr/bin/lessecho

I can not come up with an example of how I could/would use lessecho. The description in the man page is fairly straight forward but is not helping me come up with a use case: DESCRIPTION ...
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1answer
114 views

BSD Net/1 was a free fully operating system?

I think that the old BSD Net/1 was not a fully operating system, but an add-on to 4.3BSD for VAX, as I realize from http://gunkies.org/wiki/Net/1 and http://gunkies.org/wiki/Net/2 Is it right? In ...
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3answers
1k views

Why is “shebang” called “shebang”?

Does "shebang" mean "bang she"? Why not "hebang" as "bang he"?