Questions tagged [unix]
For questions about the Unix operating system.
103
questions
3
votes
1
answer
189
views
Which historical Unixes supported terminal I/O with five or six bits per character, and with what character sets?
The specification for termios.h includes a facility for controlling the number of bits per character sent over the serial line, the CSIZE and CSn constants. You can request five, six, seven, or eight ...
- 409
20
votes
3
answers
3k
views
when did command line applications start using "-h" as a "standard" way to print "help"?
I am interested to hear about the history because I have a prominent command line product that has decided to use -h for something that does not print a help message.
when did command line ...
19
votes
9
answers
5k
views
Why does cat with no argument read from standard input?
In advice about how to design good CLI commands I read:
If your command is expecting to have something piped to it and stdin is an interactive terminal, display help immediately and quit. This means ...
- 1,003
19
votes
1
answer
2k
views
Origin of UNIX symbolic links?
When I search the web for information about the origin of UNIX symbolic links, I see "Symbolic links were first introduced into Unix with 4.1c-BSD". But when I go to fact check that, it ...
- 481
25
votes
2
answers
3k
views
Did any DOS compatibility layers exist for any UNIX-like systems before DOS started to become outmoded?
Quoting from Jim Hall's "FreeDOS turns 25 years old: An origin story":
Around 1994, Microsoft announced that its next planned version of Windows would do away with MS-DOS. But I liked DOS. ...
- 551
5
votes
3
answers
419
views
Circuit design tool mentioned in AT&T Unix promotion
In this video from AT&T about Unix is a circuit design tool displayed that is claimed to be based on YACC (timestamped link).
Does anyone have information about this tool?
Like:
Documentation
...
- 101
6
votes
1
answer
372
views
Mainframe Hater's Handbook?
The famous The UNIX-HATERS Handbook claims this mailing list had been inspired by TWENEX-HATERS(1) and other *-LOVERS mailing lists, a long tradition of MIT.
Moreover, the quote below implies there ...
- 3,572
7
votes
1
answer
1k
views
When did SunOS get a graphical interface?
I understand that the first graphical user interface for SunOS was SunTools (later renamed to SunView), but I cannot find any documentation that states when it was released and for which versions of ...
- 754
7
votes
1
answer
266
views
How did Bell Labs start to work on Project MAC?
Did Bell Labs approach MIT or was it the other way around? Did participating in Project MAC come from researchers requesting management at Bell Labs/MIT or did management make the decision due to ...
- 481
31
votes
6
answers
10k
views
How could early UNIX OS comprise so few lines of code?
I start my journey to become a hardware / software specialist with an internship in two weeks time and decided to start studying the C language early.
I came across this video, Learn C Programming ...
- 5,385
20
votes
2
answers
478
views
What is the history of SysV i386 calling convention for struct return?
I would like to understand historical roots of the quirk in the SysV calling convention for the 32-bit x86, which was inherited by the ELF standard, and so remains used on Linux to this day. Consider ...
- 301
6
votes
1
answer
578
views
Can you remember the name of a public access Unix system, around 1990/1, Spug or Spud?
Hey I recall accessing a public-access UNIX system in the UK, likely around 1990/91.
I seem to recall it gave you shell access but it might actually have only been Mail or UUCP/usenet client?
I have a ...
- 61
12
votes
6
answers
8k
views
What was the original unix font?
I'm looking for a font for a tattoo. I don't have any preferred font so I thought using the original Unix font could be a great reference to the great history. Can't find any reliable information ...
Rasul
5
votes
1
answer
527
views
Oldest UNIX I can run on my modern system?
What is the oldest UNIX(-like) system that can be legally downloaded and run (in a VM or emulator) on a modern PC (running Linux)?
- 153
19
votes
4
answers
4k
views
What was the purpose of those special user accounts in Unix?
In a modern Linux system – modern enough to have upgraded useradd to a version from no earlier than February 2008 – it is usually the case that user accounts with UIDs no less than 1000 (other than ...
- 20.3k
4
votes
0
answers
269
views
What does this image in Space Travel represent?
I was touching up the Space Travel article on the Wiki and realized no one had answered a question I posted some time ago. I suspect someone here knows the answer.
This image is used in the infobox to ...
- 17.8k
11
votes
5
answers
2k
views
Early implementations of the `system()` call in a consumer OS
Nowadays, it's easy to take for granted the system() call (as defined in POSIX), which allows a user program to easily execute a child process and wait for it to complete. Obviously, this is a trivial ...
- 59.1k
5
votes
1
answer
362
views
Why did Dennis Ritchie write that UNIX was a modern implementation of CTSS? [closed]
At the Tenth Hawaii International Conference on the System Sciences in 1977 Dennis Ritchie presented the paper The Unix Time-sharing System: A retrospective in which he states:
...a good case can be ...
- 481
29
votes
2
answers
7k
views
Correct pronunciation of `vi` (Unix editor)?
According to this video with Brian Kernighan, the correct pronunciation of the classical Unix editor ed is "Eee. Dee." — not "Edd".
So that made me wonder — what about the other ...
- 419
7
votes
0
answers
231
views
Small format X terminal with EL screen
I remember an ad for a small-format (about as wide as a 60% keyboard) dark-ish grey colored X terminal that had a 12" (?) yellow electroluminescent screen similar to the Grid laptops but higher ...
- 407
10
votes
1
answer
553
views
Nontrivial B program
I have been able to find very little about the B programming language online. the predominant resources seem incomplete, particularly in regards to standard library functions. I have not been able ...
- 201
30
votes
10
answers
6k
views
What happened to all those Unix workstations in the '90s?
Around the early to mid '90s it seems there was a trend for high-end workstations running some form of Unix, and running a RISC or at least some kind of non-x86 architecture. For example:
Sun ...
- 373
5
votes
1
answer
640
views
Why did this joke man page use July 16, 1974 as an epoch?
This fake manual page posted to the comp.humor newsgroup jokes that
A.out accepts any option passed to it, stalls for a few
seconds, and then prints a cryptic message chosen from the
list below. The ...
- 15.4k
9
votes
2
answers
368
views
What environment was Coherent developed with?
Coherent was a Unix clone for IBM compatibles Mark Williams Company produced and sold in the 1980s and early 1990s.
What environment and tools was Coherent developed with? Was it cross-developed on ...
- 1,234
4
votes
1
answer
219
views
When did an overlay linker first appear in a PDP-11 UNIX OS?
On a 16-bit system with at most 64K of RAM available for a user program, one would think of having an executable overlay mechanism as an indispensable tool to maximize the amount of memory available ...
- 17.6k
11
votes
1
answer
700
views
How did early Minix represent processes
Minix, as most know, is a "Unix-like" OS originally used for teaching. Early Minix (v1 and, apparently, v2) ran on the 8088/6 series of processors. It could run on the IBM XT.
There have ...
- 11.5k
17
votes
3
answers
4k
views
What is the simplest UNIX system with a MMU?
I was recently looking at a Motorola 68010 and 68451 that have been in some ESD foam on a shelf for a very, very long time. Now, things are all so huge in memory, but BSD4.4-Lite can run in only 256k ...
- 1,069
2
votes
2
answers
1k
views
How did Unix handle multiprocessing when virtual memory didn't exist?
It seems the first "real" virtual memory management system was the i386 with its powerful paging system that totally isolates processes. How did Unix work before this, ensuring no process ...
user23544
8
votes
2
answers
2k
views
What are the "other crontabs" that /etc/crontab refer to? [closed]
The /etc/crontab file on ubuntu has a header that reads:
# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the `crontab'
# command to install the new version when ...
- 183
15
votes
1
answer
2k
views
How would old software using the SIGPIPE signal really work if it were to manage _many_ pipes?
I'm wondering what was the thinking behind having a SIGPIPE signal.
From my own experience, the first thing I do is turn off that signal (SIGIGN) and use the return value of the calls to make sure it ...
- 835
37
votes
3
answers
5k
views
Why does make only accept tab-indentation?
The syntax for Makefiles requires that indented lines start with a tab, and not a space. So far as I can tell, this has been the case even for very early implementations of make. But even modern-day ...
- 36.1k
9
votes
1
answer
1k
views
Is it true that "do ... done" blocks in Bash do not end with "od" because od existed before Bash/Bourne shell?
The Wikipedia page about od says:
Since it predates the Bourne shell, its existence causes an inconsistency in the do loop syntax. Other loops and logical blocks are opened by the name, and closed by ...
- 561
1
vote
1
answer
362
views
Did DEMOS have a C compiler?
DEMOS was a Soviet operating system derived from BSD Unix. The answer to this question shows that the familiar, English-derived BSD commands were essentially the same in DEMOS.
Did DEMOS have a C ...
- 15.4k
6
votes
2
answers
339
views
DEMOS commands: Cyrillic or Roman letters? Uppercase or lowercase?
DEMOS was a Soviet operating system derived from BSD Unix.
Commands in BSD are derived from English words. Did DEMOS use these same commands, develop their own commands but retain the Roman alphabet,...
- 15.4k
14
votes
3
answers
2k
views
What were the differences between Xenix and Unix?
According to https://en.wikipedia.org/wiki/Xenix by the beginning of the nineties, SCO was selling 32-bit 386 versions of both Xenix and Unix. According to https://news.ycombinator.com/item?id=...
- 55k
40
votes
1
answer
7k
views
What was "the shrinkwrap issue?"
I first read "Alice in UNIX Land" (by Lincoln Spector, Texas Computer Currents, Sept. 1989), probably around the time when it was written — and at that time didn't understand very many of ...
- 3,806
1
vote
2
answers
612
views
Does an OS, in particular Unix, need special support for terminal colors? [closed]
Also of interest, would be the first OS to support color graphics in other ways (assuming it wasn't a Unix).
Background: I'm thinking of playing around with Unix v6 due to all the material available, ...
- 279
8
votes
1
answer
922
views
Unix: Why was five (SysV) released *after* seven (V7)?
AT&T released UNIX Version 7 (seven) in 1979.
The same company released UNIX System V (five) in 1983.
Why did the later release have a lower number?
- 15.4k
9
votes
3
answers
1k
views
Why does -z and -n exist in most shells and /bin/test?
The test command on Unix-like systems provides two special syntax forms for checking whether a string is empty or not:
test -z "$foo" # the length of $foo is zero
test -n "$foo" # ...
- 3,288
22
votes
2
answers
1k
views
Where and when did the ".s" suffix for assembly-language source files originate?
The closest I was able to find on StackOverflow is What are .S files?, in which no answerer addresses why we use .s for assembly. (And .S for preprocessor/macro assembly; and gcc -S to produce ...
- 854
17
votes
3
answers
2k
views
Why is the Unix epoch January 1st 1970?
In honor of this weekend being 1,600,000,000 (1.6 billion) seconds since the Unix epoch, I was wondering if anyone knows why January 1st 1970 was chosen?
According to Wikipedia,
The earliest versions ...
- 653
31
votes
6
answers
9k
views
What are the major technical difference between Multics and Unix?
From the naming of operating system only i.e Unix = Uniplexed Information and Computing Service vs Multics = Multiplexed Information and Computing Service, I was first having a misconception that the ...
- 653
11
votes
2
answers
952
views
Trying to understand some assembly syntax in the Unix v7 write system call
so here is the code: (which comes from here, I've also verified this source is in my unix v7 distribution). For reference, this is running on a PDP-11 simulated with the simh program (so please keep ...
- 245
19
votes
1
answer
2k
views
Identifying late 1990s embedded 486 UNIX-like system
I'm trying to identify the operating system on a Thermo-CRS C500 robot arm controller. From the specifications I know it runs on a 100 MHz 486 processor, and has 4 MB RAM and 2MB of flash/NVRAM ...
- 1,416
13
votes
2
answers
3k
views
How did the /dev file system work in early Unix?
UNIX did not have support for virtual file systems (vnodes) until 1986.
S.R. Kleiman, “Vnodes: An Architecture for Multiple File System Types in Sun UNIX,” Summer USENIX 1986
I remember this quite ...
- 283
8
votes
4
answers
1k
views
What were the Major Public Access Unix Systems Available in the 1980s-90s?
Back in the 1980s-90s, using a UNIX system required running expensive servers or paying for timesharing service, so they were beyond the reach of most individuals, and only available to members in ...
- 3,034
43
votes
1
answer
8k
views
What warning was given on attempting to post to USENET, circa 1990?
I recall a confirmation/warning message that read something like
"this will post to thousands of sites... are you sure?"
What was a typical such message in the days of pay-per-minute dialup access?
- 2,150
17
votes
1
answer
497
views
What proprietary AT&T code/features were removed in BSD Net1 (/2), and BSD 4.4 Lite (/2) from the original 4.3BSD codebase?
Background
Although BSD and its source code was freely available under the original BSD licenses, but it only covered the portion of the code which copyright was owned by Regents of the University of ...
- 3,034
44
votes
6
answers
11k
views
How should we interpret Dave Cutler's criticism of Unix?
Dave Cutler is well known for his contributions to operating systems, having led the effort on VAX VMS at DEC and Windows NT at Microsoft. According to his Wikipedia page, he is also known for ...
- 59.1k
14
votes
6
answers
3k
views
Using only one terminal, can I interrupt a process that's hung on very early Unix versions?
Within modern shells, I am able to leave a process via one of two control sequences:
Usually Ctrl+C will directly send SIGINT to the majority of shell commands (e.g. ping, echo, cat)
A few processes ...
- 2,843