What is Unix: Definition and 43 Discussions

Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in the 1970s at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others.Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Berkeley (BSD), Microsoft (Xenix), Sun Microsystems (SunOS/Solaris), HP/HPE (HP-UX), and IBM (AIX). In the early 1990s, AT&T sold its rights in Unix to Novell, which then sold its Unix business to the Santa Cruz Operation (SCO) in 1995. The UNIX trademark passed to The Open Group, an industry consortium founded in 1996, which allows the use of the mark for certified operating systems that comply with the Single UNIX Specification (SUS). However, Novell continues to own the Unix copyrights, which the SCO Group, Inc. v. Novell, Inc. court case (2010) confirmed.
Unix systems are characterized by a modular design that is sometimes called the "Unix philosophy". According to this philosophy, the operating system should provide a set of simple tools, each of which performs a limited, well-defined function. A unified filesystem (the Unix filesystem) and an inter-process communication mechanism known as "pipes" serve as the main means of communication, and a shell scripting and command language (the Unix shell) is used to combine the tools to perform complex workflows.
Unix distinguishes itself from its predecessors as the first portable operating system: almost the entire operating system is written in the C programming language, which allows Unix to operate on numerous platforms.

View More On Wikipedia.org
  1. emilmammadzada

    TRIPOLI-4 version 9S How to installing on Unix system for Ubuntu22.04

    TRIPOLI-4 version 9S How can I find the user manual for installing and running this nuclear code?
  2. sysprog

    Windows, Unix and Macs Oh My (All OSes are Welcome)

    Computation history is cluttered with variants, by-roads, successes and failures. I really like UNIX/C as an engineer and scientist but mainly use Windows for home computing. ##-## @Klystron
  3. Ygggdrasil

    How can I use AWK to batch rename files in Unix?

    I'd like to rename a bunch of files in a directory based on data from a tab-delimited text file. I know how to do this in R: dir <- "~/user/folder/" fileNames <- read.table(paste0(dir,"fileNames.txt"),sep="\t",header=T) for (i in c(1:nrow(fileNames))){ oriFile <-...
  4. E

    Implementing a Unix Shell in C

    Homework Statement Assignment instructions are as follows: For the purposes of this assignment, we've been provided with some skeleton code (the "myshell.c" program mentioned in the instructions). I'll post it here: #include <stdio.h> #include <sys/wait.h> #include <unistd.h> #include...
  5. E

    C - getting filenames from stdin/stdout for use in getopt

    Homework Statement The assignment I'm doing involves manipulating an image stored in a 24-bit uncompressed BMP file. We were provided with two pre-written files (a header and a .c source file) that contain functions that read and write the image file, as well as a flip() function (mirrors the...
  6. E

    Tricky Segmentation Fault in C

    Homework Statement Write a C program to run on ocelot to find the total count of words and optionally the longest and or shortest words in a string input by the user or coming from a file. If there is no filename the user would be prompted to enter the string. You must use getopt to parse the...
  7. A

    .profile missing in Unix (bash shell)

    Homework Statement I'm playing around in UNIX and I wanted to modify my .profile file in my home directory, but It's not there. I know you type in ls -a to view the hidden files but it's simply not there. Do I just create one? I want it to just display my name every time i log in. Homework...
  8. Ben Wilson

    A Getting Started with CASTEP: Installing & Configuring for DFT Calculations

    Hi guys, I'm trying to use the CASTEP software for dft calculations. I have plenty of documentation on how to use it once it's all up and running, however I don't know how to get to that point :/ I'm not the best with linux but I've manually installed programs before through tarballs but here...
  9. RJLiberator

    Creating a Subset of Data with Awk Command in Unix

    Homework Statement use awk to create a subset of the original data file called subset.gmt that only contains records with longitudes between -112 and -102. Hint: you can use the operator && to tell awk to look for more than one pattern at once. Homework EquationsThe Attempt at a Solution...
  10. RJLiberator

    How to Practice Unix? Can I make my own Server?

    Warning: My terminology is horrendous in this area. Bare with me. In my Geophysics class we are being taught the very basics of Unix using 'Putting" and a program called Xming. We sign on to a server hosted by the profressor at school using designated usernames and passwords and we use...
  11. A

    Executing a compiled program in Unix

    I am using a makefile and the file is compiling without any errors. After compiling I try to execute the output file by typing ./output, but then the bash shell thing disappears and I can only type text but not give commands anymore. Anyone know what could be going on?
  12. A

    Struggling to Compile a Program in Unix? Here's What You Need to Know

    I have a climate modelling program that I need to somehow get to work. I have no experience with Unix whatsoever, so for me this is not a trivial task. I attached a screenshot of what I have. I need to compile the program and since there is a Makefile in my directory, I guess I have to use the...
  13. D

    Transfering files between a Unix account and my windows PC

    I have an account on a Unix cluster where I log in through an SSH client (I'm using SecureCRT). I need to be able to transfer files from my windows to PC to my unix acount and vice versa, does anyone know how to go about doing that? There is a "Transfer" menu in the SecureCRT window but it...
  14. B

    Solving Unix Script Problem: Finding #s w/ 5 1-4321

    Homework Statement Trying to find how many numbers contains 5 between 1 to 4321 Homework Equations n/a The Attempt at a Solution #!/bin/bash typeset -i current=1 typeset -i times=0 while [ $current -le 4321 ] ; do if [ ] ; then <<<<<<<<<<< stuck here, not sure what...
  15. L

    Copy from eclipse to vim in unix

    I would like to copy some code that I wrote in eclipse to vi text editor in unix without retyping the entire code. Is there a way to do this?
  16. F

    Help with coding my own shell in C, Unix environment

    Homework Statement Need to write my own shell in C for a Programming assignment. It must also support piping, redirection, and appending. Homework Equations The professor provided a preliminary version of the program that supports piping, but not redirection of either input or...
  17. N

    To Query the file attributes in unix using a c program

    Hello guys, I am trying to query the file attributes in unix using a c program..Little help please :)
  18. O

    What is the best Unix like OS for mathematical computation?

    I want to basically have a dedicated machine for running scientific computation programs and be able to access it remotely anywhere using a laptop/netbook. That means I don’t care much about GUIs. I’m used to using Unix and am perfectly fine with doing everything through a command window. At the...
  19. S

    How to fix EOF error when transitioning from Windows to Linux?

    I am getting a confusing EOF error. I have working code which I have tested in Cygwin on Windows, but now that I am running the same code on Fedora Linux, I am getting an EOF error in a data file that I know works. Is there something I need to do in the transition from Windows to Linux to...
  20. C

    Intro to Unix, class or online?

    So, I'm majoring in Physics and I got an email from my adviser saying that "Intro to Unix" was one of the most helpful classes. They only offer them during 2 times. One is Tuesdays 5:15pm to 6:30pm while the other is online. I've dabbled in Linux distros and use them from time to time, so I'm...
  21. Z

    Migrating makefiles from Unix to Windows

    How do I use a Unix-originated makefile on Windows Vista? Is there any simple guidelines for migrating the makefile such that it works?
  22. R

    What does the UNIX cat command do and how can I access hidden files?

    UNIX “cat” command doubts! I’n new to UNIX so please bear with me. I wanted to know what does the cat file1.txt << file2.txt command do? it doesn’t give an error, just goes accepts the keyboard as stdinput, and on ctrl+d, contents of file1 nor file2 changes. Also one more thing in the...
  23. Q

    Unix Scripting Help: Enter Inputs and Send Output to File

    hi! I am trying to create a script that will run a program, enter inputs (this program requires some inputs for it to run), and then send the output to a file. I am stuck on trying to get the script to enter in those inputs :( so far all i have is: ./program > file <input1> <input2>...
  24. cepheid

    What happened to my .txt files after accidentally using 'mv *' in UNIX?

    Hi, I was trying to type: mv *.txt some_other_directory but I accidentally hit 'return' after just typing: mv * Many of the .txt files in my current directory disappeared (but not all of them, strangely enough). Does anyone know what might have happened to them and how to undo the...
  25. H

    Search and Replace Unix Shell Script

    I'm trying to write what is basically a search and replace script. Full disclosure: This IS a homework assignment, and my attempt is below. It is supposed to have a usage statement, which I think is pretty solid so far. The problem is at the end where I do that actual searching and replacing...
  26. C

    Exploring Linux & Unix: Which Version & What Books to Buy?

    Recently I've been reading up some, and in certain communities Linux and particularly Unix are very well accepted. I want to switch over to Linux or Unix or possibly have both on my system. Any suggestions on which versions to run? So far, I think I may settle on Red Hat because some of my...
  27. moe darklight

    New OSX is UNIX certified whatever that means. is that good, bad, neither?

    Ok, I'm computer literate up to a certain limit... I was looking over the new features of os 10.5 on their website. I have no idea what UNIX is and if it goes well with tomato sauce, but it sounds important. http://www.apple.com/ca/macosx/features/300.html what does this all mean in...
  28. A

    Unix vs Linux: What's the Difference?

    I understand that you can put down UNIX as one of your skills acquired section, but can you put down LINUX as one?
  29. S

    Learn How to Write a Generic Unix Shell Script in 4 Easy Steps with ltxprc.sh

    I have never written a shell script, but I am trying to learn. I want to make a generic Unix shell script that will allow me to run four commands in a row... something like this... latex $filename bibtex $filename latex $filename latex $filename I would like to call the script...
  30. P

    Redirect Output in UNIX: How to Use freopen() to Print to Console

    So I'm using freopen to redirect output from stdout to a file... How do I redirect it back to the screen? relevant code: FILE *stream = freopen("data.txt", "w", stdout); /* print stuff */ How the heck do I get the output stream to point to the console again?
  31. O

    Create a new unix like OS with bsd licensing

    The goal would be to finally create a real competition to MS Windows. Since it can be anything, open source, closed source, do whatever on Earth you want, the competition would be great. You would get the best of both worlds, open and closed source. A company can decide to invest billions...
  32. P

    How to Implement Redirection and Piping in a C Shell Script on UNIX?

    Hello Dudes, I m writing a C shell code in UNIX that takes a user command and executes it, my shell must support the redirection and piping too. Well i succeeded in writing the first one (takes a user command and executes it ) but i m stucked in the other parts :( Can anyone help ...
  33. G

    C program to mimic wc command in UNIX

    I did it the following way. The number of characters and lines are coming out fine, but the words are usually more than the actual given by wc. #include<stdio.h> int main() { FILE *fp; int words=0,chars=0,lines=0; char prev,curr; //prev variable is included to...
  34. N

    Makefile in Unix environment: help

    NEVER MIND! I finally found a good reference explaining all of this. Sorry for the wasted bandwidth! Patrick I have this makefile I am trying to understand. It goes like this: COMP = ifort FLAGS = -autodouble etc... GLOBALS = a bunch of .o files... glue...
  35. B

    C programming in UNIX environment

    Hi, I have a question about C programming. I am going to take a class of C programming and we are going to write the codes in a UNIX environment. Because I do not have access to a "SUN" computer, is there a possibility to have a compiler that permits me to write under Windows XP but can...
  36. Monique

    Fixing Mac Fonts with Fondu & Unix Commands

    argh, this mac is making me miserable So, I want to convert some .dfont fonts to .ttf and installed fondu, which should do the work. Now, 1) how do I find out where the program got installed to, or is it supposed to disappear when it's unix based? 2) now when I type fondu in an X11 terminal...
  37. exequor

    Unix VM: What Distribution is Best? FreeBSD or Others?

    I'm thinking about running unix as a virtual machine. What is a good distribution that I should start with? I was looking at FreeBSD. By the way I don't know if I'm confusing my terminology with unix, so is there a "unix" from the open group and are the others (FreeBSD, OpenBSD, etc.) just...
  38. T

    Chmod- changing UNIX file permissions

    SOMEONE please tell me how to change my access to a folder to 755. I have WS-FTP Pro and I thought all you had to do was right click and select ftp commands however this is not an option for me
  39. F

    Love UNIX? Share Your Story Here!

    I just started a FORTRAN 90 programming class this quarter, and we do all our work on the school's UNIX servers, and I love it. The simplicity, no dealing with all the unnecessary crap windows comes attached with. I just felt like sharing.
  40. tandoorichicken

    Printing on UNIX Sys V: Finding Printer Names

    Is there a way to look up the names of printers hooked up to a particular server? I'm trying to print some of my old homework assignments that I accessed using SSH. The OS is UNIX Sys. V.
  41. G

    Are There MiKTeX-Like Systems for Unix?

    I've become rather fond of MiKTeX's package management system. The last time I actually had to manually find a package on CTAN has been a long time ago, because of MiKTeX. Just wondering if anyone knows of a similar system for Unix systems?
  42. S

    Looking for Info regarding Unix

    I'm currently doing a research paper on Unix. I dotn have any experience with it or other operating systems like it. I need to find information about the following : 1. detailed description of the underlying theory and operation of the technology 2. a summary of competing technologies...
  43. Monique

    Deleting Files from Unix Root & Subdirectories Without Going There

    Hi guys, I have been trying to get familiar with the Unix environment.. there is just one (actually two) things that I cannot figure out. It must be a trivial question for you guys. How do I delete a file from a root directory without actually going there? How do I delete all the files...