COMP 3000 2012 Week 3 Notes - Revision history

Spenner2: /* Why we're studying unix */

2012-09-30T19:14:16Z

Why we're studying unix

← Older revision		Revision as of 19:14, 30 September 2012
Line 45:		Line 45:
	** built on kernel functionality		** built on kernel functionality

	== Why we're studying unix ==		== Why we're studying <span style="text-decoration:line-through;">unix</span> Linux based operating systems==

	* all operating systems have roughly the same architecture		* all operating systems have roughly the same architecture

Cdelahou: /* Why we're studying unix */ added hole hawg link

2012-09-24T19:05:22Z

Why we're studying unix: added hole hawg link

← Older revision		Revision as of 19:05, 24 September 2012
Line 57:		Line 57:
	* windows comes from vms		* windows comes from vms
	** increment(vms) -> wnt		** increment(vms) -> wnt

			see [http://www.team.net/mjb/hawg.html Unix - The Hole Hawg].

	== Init and Shell Scripts ==		== Init and Shell Scripts ==

Cdelahou: /* History of Unix */ Added essential R. Stallman cultural references

2012-09-24T18:59:44Z

History of Unix: Added essential R. Stallman cultural references

← Older revision		Revision as of 18:59, 24 September 2012
Line 128:		Line 128:
	* POSIX standard was an outcome of the fragmentation		* POSIX standard was an outcome of the fragmentation
	* Free Software Foundation came out of the fragmentation		* Free Software Foundation came out of the fragmentation
	** founded by rms (Richard M. Stallman)		** founded by rms ([http://xkcd.com/225/ Richard] M. [http://www.youtube.com/watch?v=1sxNy0qQDkU Stallman])
	** not initially a very open development environment		** not initially a very open development environment
	** built all the components of unix called GNU (GNU's Not Unix)		** built all the components of unix called GNU (GNU's Not Unix)

Cdelahou: /* Init and Shell Scripts */ added a tiny bit of info and narrative changes

2012-09-24T18:48:40Z

Init and Shell Scripts: added a tiny bit of info and narrative changes

← Older revision		Revision as of 18:48, 24 September 2012
Line 67:		Line 67:
	** /etc/init.d/networking [start\|stop]		** /etc/init.d/networking [start\|stop]
	** /etc/init.d/networking [start\|stop]		** /etc/init.d/networking [start\|stop]
			'''Note:''' ''command'' [ ''keyword1'' \| ''keyword2'' \| ... ] means to execute a command with an optional choice of two or more keywords.
	* shell scripts		* shell scripts
	* start with		* start with
Line 73:		Line 74:
	** #!/bin/ksh		** #!/bin/ksh

	~~Ann passes the lecture to~~ Anil Somayaji
			''Enter'' Anil Somayaji.

			''[http://en.wikipedia.org/wiki/Exeunt Exeunt]'' Ann ''stage left''.


	* Init scripts		* Init scripts
Line 82:		Line 87:
	* A file starting with #!		* A file starting with #!
	** next comes the path to an interpreter for the rest of the file		** next comes the path to an interpreter for the rest of the file
	* common directories		=== Common Directories ===
			see [http://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard Filesystem Hierarchy Standard] and [http://www.pathname.com/fhs/pub/fhs-2.3.html FHS 2.3]
	* /etc		* /etc
	** pronounced ett-see		** pronounced ett-see
	** configuration		** system wide configuration files
	** different subdirectories		** different subdirectories and directory structures
			** Competing Unix cultures apparent in the naming conventions and directory structures
	** /etc/<prog>.conf		** /etc/<prog>.conf
	** /etc/<prog>/~~[[User:Sdp\|Sdp]]~~		** /etc/<prog>/
	** /etc/<prog>.d/~~[[User:Sdp\|Sdp]]~~		** /etc/<prog>.d/
	* /bin		* /bin
	** system binaries		** system binaries
	** often this is local		** often this is local
			** Bare minimum of what's needed to boot.
			** Important for diskless systems (see /usr/) or think clients.
			** Historically, we kept this as small as possible
	* /lib		* /lib
	** system libraries		** system libraries
Line 99:		Line 109:
	* /usr		* /usr
	** often this is shared		** often this is shared
			** Historically, the /usr/ directory was a remote file system mounted after the system had fully booted. Servers had more disk space than terminals/thin clients.
	** /usr/bin		** /usr/bin
	** user binaries		** user binaries

Cdelahou: /* Why we're studying unix */ typo

2012-09-24T18:21:02Z

Why we're studying unix: typo

← Older revision		Revision as of 18:21, 24 September 2012
Line 53:		Line 53:
	** Example: On Unix, configs reside in flat text files. In Windows, they live in an opaque key/value store called the registry.		** Example: On Unix, configs reside in flat text files. In Windows, they live in an opaque key/value store called the registry.

	Despite the similarities between OS families, Unix systems tend to be built much more transparently, which makes it a good vehicle to study OS topics		Despite the similarities between OS families, Unix systems tend to be built much more transparently, which makes them a good vehicle to study OS topics

	* windows comes from vms		* windows comes from vms

Cdelahou: /* Why we're studying unix */ added a few points

2012-09-24T18:20:32Z

Why we're studying unix: added a few points

← Older revision		Revision as of 18:20, 24 September 2012
Line 47:		Line 47:
	== Why we're studying unix ==		== Why we're studying unix ==

	* all operating systems have ~~basically~~ the same architecture		* all operating systems have roughly the same architecture
	* windows is just a variation on unix		* windows is just a variation on unix. Built and designed very similarily.
			* "Like a different accent. Same everything, but renamed"
			* Slight differences in the way things are done
			** Example: On Unix, configs reside in flat text files. In Windows, they live in an opaque key/value store called the registry.

			Despite the similarities between OS families, Unix systems tend to be built much more transparently, which makes it a good vehicle to study OS topics

	* windows comes from vms		* windows comes from vms
	** increment(vms) -> wnt		** increment(vms) -> wnt

Sdp: Added second lecture

2012-09-24T16:34:33Z

Added second lecture

@@ Line 51: / Line 51: @@
 * windows comes from vms
 ** increment(vms) -> wnt
 == References ==
 {{note|vmlinux}}: https://en.wikipedia.org/wiki/Vmlinux

Sdp: proper mediawiki footnote reference

2012-09-20T21:09:08Z

proper mediawiki footnote reference

← Older revision		Revision as of 21:09, 20 September 2012
Line 10:		Line 10:
	** sort		** sort
	*** takes input on STDIN, sorts lines, prints to STDOUT		*** takes input on STDIN, sorts lines, prints to STDOUT
	* vmlinux is the linux kernel with virtual memory ~~[1]~~		* vmlinux is the linux kernel with virtual memory {{ref\|vmlinux}}
	** vmlinuz is the same but compressed		** vmlinuz is the same but compressed
	* bash runs on vmlinux		* bash runs on vmlinux
Line 54:		Line 54:
	== References ==		== References ==

	~~[1]~~: https://en.wikipedia.org/wiki/Vmlinux		{{note\|vmlinux}}: https://en.wikipedia.org/wiki/Vmlinux

Sdp: added my notes for week 3 lecture 1

2012-09-20T21:05:02Z

added my notes for week 3 lecture 1

New page

== Shell ==

* useful command line programs
** bc -l
*** command line calculator
** cal
*** command line calendar
** uniq
*** filters out duplicate lines
** sort
*** takes input on STDIN, sorts lines, prints to STDOUT
* vmlinux is the linux kernel with virtual memory [1]
** vmlinuz is the same but compressed
* bash runs on vmlinux
** most programs run on bash
** ls/cd also run on vmlinux
** ls runs as a child process of bash
* to get rid of a misbehaving child
** the parent must kill it
** waits for child to die
** an unreaped child becomes a zombie
** zombies can't be killed, must be reaped
** to kill a zombie, must kill parent
** orphans become a child of init (ward of state)
** init is good at reaping children

== job control ==

* job is a process
** term comes from batch processing
* Useful control sequences
** Ctrl-C
*** terminate job
** Ctrl-Z
*** stop job
* To start a stopped job in the foreground
** fg %n
*** where n is the job number
* To start a stopped job in the background
** bg %n
* To determine jobs that are running
** jobs
* Who manages jobs?
** the shell
** built on kernel functionality

== Why we're studying unix ==

* all operating systems have basically the same architecture
* windows is just a variation on unix
* windows comes from vms
** increment(vms) -> wnt

== References ==

[1]: https://en.wikipedia.org/wiki/Vmlinux