Questions tagged [history]
The history of Unix systems and their main components. Please DO NOT USE this tag for shell-related questions; use "command-history" instead.
376
questions
0
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0answers
41 views
What does (or did) the name “feh” represent?
To me, the name of the feh image viewer is not memorable enough for me to recall it when I need it. I feel that if I had some context, I'd be able to remember it better.
What, if anything, does the ...
8
votes
1answer
229 views
Who decided the bc math library will define sine cosine and arctangent?
If you load the bc math library you get the trig functions s() and c() and a() which are sine, cosine, and arctangent respectively. Why these three functions?
I know why it's those three from the ...
5
votes
1answer
91 views
Difference between command `command` vs command `builtin` in Shell Scripting
I understand the command command is specified in the latest POSIX standard and builtin is not. I also realize that both commands are regular builtins (i.e. they can be overwritten by user-defined ...
12
votes
1answer
968 views
Why do ^M and \r behave inconsistently?
Perhaps there are already answers out there that indirectly answer my question, but I've read many of them and haven't yet found a satisfactory answer to this discrepancy.
The original meaning of ...
2
votes
1answer
122 views
Why is not 'test -z =' an error after all?
I have a book that stated:
"....For example, if the shell variable symbol contains an equal sign,
look at what happens if you try to test it for zero length:
$ echo $symbol
=
$ test -z "$...
0
votes
1answer
36 views
Bash character ! of special history command
How do we change bash character ! for special history command to other direct single key character such as = ?
5
votes
5answers
393 views
why are the definition of true and false in stdbool.h the exact opposite from the UNIX programs true and false?
stdbool.h is usually defined as:
#define false 0
#define true 1
(Sources: OpenBSD, musl, etc.)
whereas the unix program false - which just has a unsuccessful status code, is defined as:
int
main(...
2
votes
0answers
135 views
What format does syslog() use when writing to /dev/log?
I initially thought to post this to StackOverflow because my interest was primarily from a programming focus, but after reading about the history tag (and the question it linked to), I posted it to ...
0
votes
0answers
138 views
History command not working in VIM
I am trying to append or export the terminal's history into my history.html for a class. I am using Ubuntu 18.
I use history >> history.html that I am executing in another file but it gives me ...
11
votes
1answer
494 views
What was the first file system in Linux distribution/s?
What was the first file system in Linux distribution/s?
The "parallel" to FAT (?) in Windows at the early nineties?
I want to know the name to read information about this; perhaps it was the ...
3
votes
0answers
46 views
Why has ls never had a parsable option implemented? [duplicate]
So we all know you shouldn't parse ls for many reasons, mostly due to filenames allowing almost every character. However why has nobody been able to overcome this in an implementation of ls?
Many ...
0
votes
0answers
32 views
What is the history of command line argument format (--arg and -arg) we commonly use today?
There is no requirement from most programs to get their arguments in format but it is now settled that all command line programs use this kind of format for arguments. I can easily make other formats ...
0
votes
2answers
50 views
How to remove up arrow to search the history?
I am not really good with Linux but I got one premade server which has Linux on it to supervise.
The OS is CentOS 7. I noticed that the up arrow allows the search of past commands (not only for the ...
4
votes
3answers
643 views
Were there Unix equivalents to BBSes?
During the 1980s and 1990s Bulletin Board Systems (BBS) were widely used on all kinds of computers. The BBS Documentary documents the rise and fall of the BBS subculture.
Watching this documentary ...
1
vote
1answer
114 views
Since when do Unix systems support birth/creation time (btime/crtime) for files and directories?
Does anyone know when Unix supports birth/creation time stamps for files and directories? If possible also when first file manager (GUI) displays it by default for users.
For comparison with Windows, ...
1
vote
2answers
251 views
What is the historical reason for limits on file descriptors (ulimit -n)
When I first borrowed an account on a UNIX system in 1990, the file limit was an astonishing 1024, so I never really saw that as a problem.
Today 30 years later the (soft) limit is a measly 1024.
I ...
1
vote
0answers
58 views
Why does ed support backreferences but not alternations in regular expressions?
I was looking into the history and development of regular expressions. I found the following timeline:
1956 -- Kleene introduces regular expressions in his paper on nerve nets.
1964 -- Brzozowsi ...
3
votes
0answers
104 views
Why does ZFS rollback destroy intermediate snapshots?
Having used btrfs before, I was surprised to find out that rolling back a snapshot in ZFS not only changes the “working set” of files, but also requires that any snapshots which are newer than the ...
3
votes
1answer
37 views
Less stopped saving search history
less used to save my search history to $HOME/.lesshst. A few days ago it stopped saving any new search patterns. I still see the old search patterns in $HOME/.lesshst, but the new ones are not saved ...
1
vote
1answer
1k views
Why is the Mesa OpenGL driver for Intel chips called i965?
As I understand, most Intel GPUs are supported on Linux by two different components : i965 (the Mesa/OpenGL part, supporting all recent Intel GPUs) and i915 (kernel part, similarly supporting all ...
8
votes
1answer
524 views
How did /var/lib get its name?
The Linux Filesystem Hierarchy Standard says that /var/lib "holds state information pertaining to an application or the system."
FreeBSD doesn't mention /var/lib in hier(7). The closest ...
2
votes
1answer
68 views
Did fwrite/fread(3) offer different “multiple items” behavior on different platforms historically?
The fread(3) and fwrite(3) have an extra parameter for a variable number of items. So a typical write often has a hardcoded count when all it has is a char buffer to begin with e.g. fwrite(data, len, ...
11
votes
1answer
1k views
Why does `dd` have `swab` functionality
The manpage for dd notes an option swab
swab swap every pair of input bytes
Why?
Don't ask me what I'm trying to do -- I'm not doing anything in particular, I'm just scratching my head. If were ...
1
vote
2answers
124 views
when /proc/cpuinfo begin to update all the time, especially the field “cpu MHz”? [duplicate]
I saw that /proc/cpuinfo update all the time, especially the field "cpu MHz"? I assumed that these details should be constant.
When did /proc/cpuinfo begin to update all the time, especially ...
5
votes
2answers
141 views
What ever became of the “prep” program? And what can I use instead on modern Linux systems?
Long ago, in Seventh Edition UNIX (a/k/a V7), there was a program called prep. Its primary use was to take files of text, and break them up into one word per line, for further processing by other ...
2
votes
1answer
64 views
Proprietary files during the Unix wars
While reading some papers on the history and evolution of Unix, I keep falling on this text in some way or another even here about some files that were proprietary of AT&T and present in BSD ...
1
vote
2answers
239 views
Difference between bash $HOSTNAME and tcsh/zsh $HOST
Is there any difference between bash's $HOSTNAME and zsh's $HOST?
If no, is there a historical reason for bash to chose the $HOSTNAME variable when tcsh and zsh use $HOST?
-5
votes
3answers
188 views
is Linux a reverse engineering thing of Unix
I'm new to Unix/Linux, sorry if my question is dumb, below is my understand of the relationship of Unix and Linux, please correct me if I was wrong:
Linus Torvalds wrote Linux kernel based on Unix (...
-3
votes
1answer
271 views
What does LINUX stands for
Does the term "LINUX" stands for anything. Until now, I was of the opinion that this term is derived from "LINUS". However, some articles on internet give following:
Linux = Linus Torvald's Unix
...
1
vote
3answers
428 views
What does the letter 'u' mean in umask?
Is it "user mask" or something?
Wikipedia does not have details, but says the feature has been in Unix since 1978.
POSIX just says it is the "file mode creation mask".
2
votes
3answers
577 views
Why is an executable called a “text file”?
In the course of updating software today I got the error "Text file busy", which got me wondering: Why is a Unix (or Linux) executable called a "text" file when that seems so counterintuitive and ...
23
votes
3answers
4k views
Why is cp's option not to overwrite files called --no-clobber?
cp is a massively popular Linux tool maintained by the coreutils team of the GNU foundation.
By default, files with the same name will be overwritten, if the user wants to change this behaviour they ...
0
votes
2answers
96 views
Historically as well as today, what was or is the commonly accepted default argument for a command to show its help page?
I stumbled upon this the first time when I wanted to add an option -h to my program and got an error that -h is already in use: With add_help=True, Python's argparse automatically creates a help page ...
2
votes
2answers
281 views
What are EL2HLT, EL3HLT, EL3RST?
There was a thread about ENOANO, explaining an obscure errno macro that still lingers around.
I would like to similarly ask about these errno values: what the hell were they for?
EL2HLT "Level 2 ...
3
votes
1answer
98 views
Why isn't installing with apt/yum to a home directory a mainstream feature?
This is a history related question of a sense, tightly related to the use cases of Linux. Am open to closing it if it's off topic.
Why is the default to always use sudo when installing with package ...
2
votes
1answer
139 views
How can I find out more about the history of GNU coreutils commands?
Can I somehow find out more about the history of the development process of the GNU coreutils commands? For example, have su and runuser (which provide kind of similar functions, yet were decided to ...
-3
votes
1answer
104 views
What is the 38;5 sequence in $PS1?
I tried to find info online, but I could not find any. It seems that many people use a specific sequence of numbers, without actually providing any explanation why.
More specifically, my $PS1 in ...
2
votes
2answers
2k views
why does rm need -r for an empty folder?
One thing that always bugged me:
touch a
rm a
ok, it works as expected
mkdir a
rm a
will require -r to work; but I don't understand what is recursive in this? if the folder is empty, there is ...
2
votes
2answers
651 views
Origin of the word console in computing
Nowadays within the programming community, console mostly refers to a text-based environment, either software (shells, terminals, cli) only or hardware included. But why is it so called?
0
votes
0answers
119 views
What happened to Bento Linux?
I came across a nifty device at a yard sale from ~2010, and at the time there was a distro called Bento Linux that had been ported to run on it. It seems that that distro died, but there are a ...
2
votes
6answers
2k views
Redirect output on-the-fly - looks not possible in Linux, why?
I tried web search but have not found answer by searching for Linux redirect output on the fly. As far as I understand, output to say stdout works by using file descriptor 1:
$ ls -l /proc/pid/fd/1
...
37
votes
3answers
7k views
When did Unix stop storing passwords in clear text?
When did Unix move away from storing clear text passwords in passwd? Also, when was the shadow file introduced?
3
votes
1answer
231 views
What is the historical reason for using curly braces {} as placeholder in find -exec
Everyone knows find . -exec foo {} \; and at some point stopped thinking about it. But recently I came back to the question that arose when I first learned it:
Why would anyone choose {} as the ...
2
votes
1answer
78 views
Was /etc/yum/repos.d ever a thing?
In some places I've read, users have mentioned the path /etc/yum/repos.d along side /etc/yum.repos.d. Was this a path that actually used at some point?
I even loaded of CentOS 5.11 and it's still /...
1
vote
1answer
85 views
How to find the changes done to a particular kernel module through all releases
I need to access source code of all past versions of read_write.c under /fs/ from 3.10 to 5.3.
So far I had to go through https://elixir.bootlin.com/ repeatedly and look at every single version that ...
1
vote
1answer
210 views
Ampersand in the passwd GECOS field
When expanding the /etc/passwd GECOS field to get the user's full name, should we expand only the first ampersand (& character), or all ampersands?
In a GECOS field with comma (,) delimited ...
2
votes
2answers
113 views
Why is the which command so hard to eradicate? [closed]
I'm coming from places like Why not use "which"? What to use then? and https://stackoverflow.com/questions/592620/how-to-check-if-a-program-exists-from-a-bash-script and am myself a long-...
1
vote
1answer
797 views
How to capitalize the word “unix”
Is "unix" supposed to be "unix", "Unix", or "UNIX"?
The closest question I've seen is Expansion of the word UNIX. I also found this page that says it is only capitalized at the beginning of a ...
0
votes
3answers
160 views
Kind of files which just have extension, like .bashrc or .cshrc
I'm wondering about files that have a name starting with a dot e.g.
.bashrc or .cshrc have distinct feature? (Could we say .bashrc extension?)
Maybe these kind of files are a member of a category?
...
0
votes
2answers
113 views
Why does the command 'source' have that name?
I wonder why a command that executes commands from a file in the current shell is named source. I can't see a relation between run commands in the current shell and the meaning of the english word ...
