The history of Unix systems and their main components.

learn more… | top users | synonyms

10
votes
0answers
49 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 ...
5
votes
2answers
130 views
+50

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 ...
21
votes
4answers
2k 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?
2
votes
2answers
35 views

Why is NetworkManager package name upper case?

All other software packages are lower case, so why NetworkManager upper case?
64
votes
3answers
4k 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, ...
16
votes
2answers
1k views

Why is JFS so obscure?

When I first got into using Slackware years ago I quickly learned to love JFS over ext3 or reiserfs given that it was reliable and if there was an unclean shutdown, its disk checking was very very ...
22
votes
3answers
3k 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 ...
1
vote
1answer
34 views

How would you get all users history

I know there is the $HISTFILE variable where i can find the currently logged in users history-file, but how can i be sure to get every history file on the server I was thinking of the ...
14
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, ...
28
votes
5answers
694 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 ...
65
votes
4answers
6k 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. ...
3
votes
3answers
101 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 ...
17
votes
1answer
791 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?
27
votes
3answers
6k views

What did Ken Thompson mean when he said, “I'd spell create with an 'e'.”

Ken Thompson, the creator of Unix, was once asked what he'd do if he had it to do over again. He said, "I'd spell create with an 'e'." What is Ken referring to? Is there a "creat" command?
10
votes
4answers
3k views

Evolution of Operating systems from Unix

Can you explain the evolution hierarchy of operating systems (Linux and Windows) from Unix?
2
votes
1answer
51 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 ...
73
votes
6answers
21k views

Where did the “wheel” group get its name?

The wheel group on *nix computers typically refers to the group with some sort of root-like access. I've heard that on some *nixes it's the group of users with the right to run su, but on Linux that ...
42
votes
4answers
4k 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 ...
4
votes
2answers
95 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 ...
4
votes
1answer
186 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 ...
0
votes
1answer
298 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
2answers
27 views

How to set the number of commands history recalls

I am using bash. To browse my command history I am calling the history command which I believe is calling the Gnu program of the same name. (I don't know if there's a better bash specific way). In ...
5
votes
2answers
201 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... ...
88
votes
3answers
12k views

What does “rc” in .bashrc stand for?

Is it "resource configuration", by any chance?
2
votes
3answers
125 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, ...
7
votes
1answer
94 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 ...
36
votes
1answer
1k 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
56 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 ...
4
votes
1answer
180 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) ...
19
votes
1answer
678 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 ...
4
votes
1answer
87 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
50 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 ???
10
votes
2answers
347 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 ...
1
vote
2answers
260 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 ...
1
vote
1answer
112 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 ...
1
vote
1answer
59 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 ...
16
votes
2answers
1k views

What is Unix now?

As I read in Wikipedia, Unix started as a revolutionary operating system written mostly in C allowing it to be ported and used on different hardware. Descendants of Unix is mentioned next, mostly BSD. ...
0
votes
0answers
75 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 ...
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 ...
4
votes
1answer
55 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 ...
12
votes
2answers
10k views

What is the concept behind “tty” in linux?

Where did the terminology "tty" come from in Linux?
112
votes
5answers
9k 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 ...
12
votes
3answers
572 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?
3
votes
1answer
120 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 ...
13
votes
2answers
419 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 ...
5
votes
4answers
300 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, ...
491
votes
2answers
117k 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?
71
votes
3answers
10k 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?
27
votes
5answers
5k 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 ...
3
votes
1answer
368 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 ...