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

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87
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3answers
16k 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. ...
1
vote
2answers
2k 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 ...
2
votes
1answer
33 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 ...
18
votes
3answers
576 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 ...
2
votes
1answer
200 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 ...
1
vote
0answers
35 views

Detailed history of all commands/actions (also in GUI)

The famous history command shows us a list of recently executed commands. If we set the HISTTIMEFORMAT variable we can also see when the commands where executed. I would like a more general version of ...
6
votes
1answer
252 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?
23
votes
2answers
475 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 ...
-1
votes
1answer
93 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?
5
votes
3answers
199 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 ...
0
votes
1answer
58 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 ...
2
votes
1answer
35 views

Why do I get different results with the same user and the history command?

I work with Linux for quite some time and have seen this behaviour but I never got a good explanation. Probably it's even very simple. If I login twice with the same user (bash) in the same server ...
19
votes
5answers
5k 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 ...
148
votes
5answers
19k 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 ...
0
votes
0answers
23 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 ...
20
votes
3answers
372 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 ...
11
votes
3answers
661 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 ...
0
votes
1answer
51 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 ...
8
votes
1answer
153 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 ...
2
votes
1answer
19 views

Why did “argument can be squisehd 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: ...
0
votes
1answer
78 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, ...
7
votes
1answer
514 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) ...
32
votes
1answer
4k 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 ...
0
votes
2answers
82 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 ...
111
votes
5answers
31k views

Is Linux a Unix?

So, there are lots of different versions of Unix out there: HP-UX, AIX, BSD, etc. Linux is considered a Unix clone rather than an implementation of Unix. Are all the "real" Unices actual descendants ...
28
votes
4answers
3k views

What is GNU Info for?

I understand what GNU Info is and how to use it, but what is it for? Why does it exist in parallel to the man pages? Why not write detailed man pages rather than provide a separate utility?
0
votes
1answer
31 views

Sourcing a redistributable script by default

I am creating a bash script which I wish to release on github. The script needs to access the command history but this is not possible without sourcing that script. I don't want users to put it in ...
1
vote
1answer
270 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
votes
1answer
153 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 + ...
3
votes
1answer
67 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 ...
19
votes
1answer
713 views

What shells were used on early unix systems?

According to wikipedia, the Bourne shell was introduced in 1977 and C shell in 1978, but unix itself dates back to 1969. If you were using a unix system before 1977, what shell would you have been ...
0
votes
1answer
62 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. ...
6
votes
3answers
666 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 ...
10
votes
2answers
185 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 ...
0
votes
1answer
105 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 ...
103
votes
3answers
7k 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, ...
3
votes
1answer
105 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 ...
5
votes
1answer
135 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. ...
0
votes
0answers
98 views

Specifying numeric ranges in zsh history

According to the docs I can tell the zsh history to print lines in a range. The docs say "history [first [last]]" I've tried "history a b" but that gives a too many arguments error. I've also tried ...
-3
votes
3answers
427 views

Why is “shebang” called “shebang”?

Does "shebang" mean "bang she"? Why not "hebang" as "bang he"?
3
votes
1answer
131 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 ...
6
votes
3answers
217 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 ...
0
votes
3answers
1k views

Who wrote the “Linux kernel” (Linus Torvalds and his team)?

Who are the authors of the pure Linux kernel from scratch, which was integrated with GNU tools and formed the full GNU/Linux Operating system in the 1990s? I have read some wiki articles but I haven't ...
1
vote
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 ...
9
votes
1answer
176 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 ...
570
votes
2answers
124k views

Why was '~' chosen to represent the home directory?

I have often wondered why the ~ represents the home directory of a user. Is there a reason behind this, or is it just some infrequently used character?
22
votes
5answers
2k views

What aspects of Plan 9 have made their way into Unix?

Plan 9 was developed by Bell Labs as a successor to Unix. Although for various reasons it never quite materialized as such, a fair amount of development still went into Plan 9. My question is, what ...
1
vote
1answer
111 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 ...
35
votes
3answers
11k 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 ...
3
votes
1answer
88 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 ...