UNIX 101:
UNIX For Windows
Users
Lecture 1
9 September 2005
Sponsored by ACM
1
The Cold Hard
• This course isTruth sponsored
NOT officially
by the CS department
• You will NOT receive credit for this
course - neither will we for that matter
• If we say something that offends you, deal
with it.
• You should try NOT to snore when you fall
asleep
• We did this course on our own time, so try
to make the best of 2it for all of us.
Just Who Do We
Think We Are?
• Mark Kegel - Tall Guy with Black
Hair
• mkegel@cs.hmc.edu
• Marshall Pierce - Broad Shouldered
Guy
• mpierce@cs.hmc.edu
3
And Just What Do
We Think We’re
Doing?
• We are here to teach you (what we
think are) the fundamentals of Unix.
• We are here to teach you to teach
yourself about Unix.
• We’re on a mission from God.
4
Never Mind Us,
Who Are You
People?
• Students who have no experience
with Unix
• Students who have some experience
but want a better grounding in Unix
• Someone who is lost, confused, and
looking for spiritual enlightenment
5
Some Reasons to
Learn About Unix
• Growth of Linux
• OS X is based on Unix
• Expanded skill set - useful
knowledge
• You want to be a l33t h4X0r
• BTW, you will always be teh newb
6
Some Better
Reasons to Learn
• I wantAbout Unix
to show my girl\boy-friend
some cool Unix tricks
• FYI: Real CS Majors never see the
light of day much less significant
others
• I am a CS major...
• ...or I plan on taking a class (CS60
or above) from the CS department
7
The Best Reasons
To Learn About
Unix...
• As a CS major at Mudd you need to
have a working knowledge of Unix
• The CS department refuses to offer
a Unix course (they do have good
reasons though!)
• But why are you really here?
8
To Make This
Perfectly Clear...
• We will NOT teach you how to use
application XXXX or show you neat
tricks for application XXXX
• This course is not the equivalent
of a course in Word or Excel
• We will also NOT teach you to how
to program in Unix
9
Down To
Business... To
• Computing Resources Available
You
• Terminal Room: Beckman B102
• Mac minis (aren’t they just so
cute)
• Printer: gute.cs.hmc.edu
• Graphics Lab: Beckman B105
• some old’n’busted computers
10
• AC and LAC Labs
• Windows and Mac Computers
• Printers: Odie and Cujo, Clifford
and Astro
• Scanners in alternate AC lab
• Engineering Lab
• Houses engineers, avoid at all costs
(they snarl and bite; Holy Water
and Crosses are said to keep them
away)
11
All-Campus Servers
• odin.ac.hmc.edu
• RHEL server; Student POP server
• thuban.ac.hmc.edu
• VMS server; hosts DNS
• banshee.st.hmc.edu
• Huge Cisco box; campus wide
router
12
CS Dept. Servers
• turing.cs.hmc.edu (sparc)
• primary work server - you’ll do
most of your work from here
• knuth.cs.hmc.edu (x86)
•our new server - where you ought
to be working when you can
• wilkes.cs.hmc.edu (x86)
•alternate work server
• muddcs, ark, cortana, durandal
13
The Doctor Will See
You Now
• Mudd employs several whose jobs
entail fixing computer and network
problems
• Tim Buchheim - Computer Science
Dept.
• Maintains the CS Department
computers
• Roger Wiechman - CIS
• Maintains the Mudd Network
14
When Hippies
walked the earth...
• Computers were real dinosaurs
• Barely had timesharing systems
• No video terminals - teletypes
instead
• RAM and CPU power limited
• there’s only so many beads you
can fit on an abacus
15
When Hippies
walked the earth...
• Ken Thomson
• Invented UNICS in 1969
• UNIplexed Information and Computing
Service
• That year also ARPANET, and man most
likely landed on the moon
• Why? He needed a way to play a game...
• After that Unix's history is kind of a blur
16
Unix Today
• Fundamentally multi-user and multi-
tasking
• Programmer’s and tinkerer’s
environment
• Support and encouragement for hacking
the system; FOSS is your friend
• Powerful tool in the right hands
• Runs the world’s most powerful
computers
• Is a thirty year old OS that Microsoft
17
The Idea of Unix?
• Unix is more than an OS, it is
• a programming language - C
• a broad philosophy of how
computers and users should
interact
• an interface - POSIX
• more than the sum of its parts
• the code that Ken Thomson wrote?
18
A discourse on the dialectic sublimation
inherent in the praxis of methodological
• Programs should be designed to work
analysis of UNIX philosophy.
together
• Accept input that isn’t strictly
formatted
• Produce output that is nicely
formatted
• Should work exclusively with text
streams
• Programs should be simple and small
• Do one task, and do that task well
19
More Unix
Philosophy...
• KISS - Keep It Simple Stupid
• Keep things as simple as possible
• Separate Mechanism From Policy
• Users should be able to decide
how a program is to look and
behave
• Internals (Mechanism) should not
be locked into one policy
20
More Unix
• Principle of Least Surprise
Philosophy...
• When programs have nothing
important to tell you, they will tell
you nothing
• Programs should die early and
noisily when they die
• There is no “One True Way”™
• Unix is not perfect!
Windows
But it’s still better than
• Many more philosophical rules than
21
http://pangea.stanford.edu/computerinfo/unix/overview/advantages.html
- The traditional command line shell interface is user
hostile
-- designed for the programmer, not the casual user.
- Commands often have cryptic names and give very little
response to tell the user what they are doing. Much use of
special keyboard characters - little typos have unexpected
results.
- To use Unix well, you need to understand some of the
main design features. Its power comes from knowing how
to make commands and programs interact with each other,
not just from treating each as a fixed black box.
- Richness of utilities (over 400 standard ones) often
overwhelms novices. Documentation is short on examples
and tutorials to help you figure out how to use the many
22
Pleasure You Want.
Protection You Trust.
• Everything in Unix is owned by
someone
• Files, programs, devices, etc.
• Unix protects users, their data, and
their programs from one another
• Regular users are not allowed to do
dangerous things to the system
• Distinction between being a “user”
and being an “admin”
23
Three types of
• lusers...err(aka root)
Administrative users users
• Complete control over everything
on the system - allowed special
privileges
• Can become any user on the
system
• Exists on nearly every Unix-based
system
• Used for System Maintenance and
Administration24
Returning to Normal
• Normal Users (aka you, me, and
crazy ivan)
• Allowed to use most of the
programs on the system
• Have a special area all to yourself
• Home directory - belongs to
you!
• Stores user specific programs,
data, and configuration
information
25
There’s just
• nobody@home.com
System users
• generally used to run daemons
• Why would running a daemon as a
regular user or as root be a
problem?
• do not usually have home directories
• you cannot log in as one of these
users
• examples: bin, lp, mail, pop, sshd,
nobody 26
Unix Rockstars and
their Groupies
• Group: a set of users
• Every user belongs to at least one
group: their primary group
• Groups allow for easier management
of a system
• students group on turing
• operator group for consultants
27
Unix Pre-School:
Logging In
• If you don’t have an account on knuth, go
see Tim!
• Every user has a username and a
password
• Passwords are secret; usernames are not
• Do your best to keep passwords
secret!!
• You should try to have as strong a
password as you can remember
28
Should be P@$$w0rds
•g00D at least 8 characters long
• Should include special characters
• Digits, - @ ! # $ % ^ & . , ( ),
spaces
• Use a mix upper and lower case
letters
• Never use a plain dictionary
password!
• elephant is not a good password
• Pass-phrases are better
29
Sessions aof theline
• Unix is at its heart command
OS Heart
• Invented in the days of the
teletype
• Physically separated input and
processing
• location of the teletype
unimportant
• Today we use emulated terminals
• Unix offers graphical environments,
but that isn’t where the real power
30
The Blinking Cursor of Doom
Why learn to use the command
line? you like it or
• You have to whether
not
• Simple, Quick, and Powerful
• Efficient
• Superior for certain tasks
• New way for you to think about how
to interact with a computer
• Necessary skill to be a Power User
• Gives +4 to your Geek skill; -4 to
Social Interaction and Aroma
31
Home Sweet yourself in your
• When you log in you’ll find Home
home directory
• Located at (on most *nixes)
• /home/username, 1328 Mulberry Drive
• Stores all you personal configuration
information
• Is where you’ll keep all your data:
homework, documents, etc
• Is your personal space; can do whatever
you’d like 32
Directory Tree
Unixdirectories are separated with
• Unix
the / (slash) character
• The Unix directory tree starts at /
(root)
• Devices can be located most
anywhere on the tree (no Windows
A:, C:, D:, stuff)
• The directory tree is filesystem
independent
• Do you know which computer your
33
Introducing The
Shell program
• The shell is an interactive
that sits between you and the OS
• Is executed as soon as you log in
• Translates your commands into
actions that the computer can
perform
• shell == “command interpreter”
• The shell is your new best friend;
you’ll have lots of fun together.
34
Syntax of a
Command
• Any line with a % preceding it is
probably happening on the command
line
• Jobbies in brackets [~~~] are
optional
• Jobbies in angle brackets are
required
• Command syntax
• % command [switches] [arg1] [arg2] ...
•(output here) 35
• Switches (aka flags) are special
Switches
arguments passed in to a program to
alter its behavior
• Follow two general styles - Unix and
GNU
• Unix: dash ‘-’ followed by a single
character
• GNU: Double dash ‘--’ followed by a
word
• Programs can take many, many
switches
• Newer programs may also have Unix
36
Arguments
• Like switches, variable in number
• Provide some form of data that the
program can operate on
• Can be filenames, email address,
another command, keywords to search
for, patterns, text, random gibberish
(or is it?)
• You should get conformable with both
switches and arguments
• BE CAREFUL WHAT YOU TYPE !!
37
Basic Commands
38
Basic Commands
39
Basic Commands
40
things to
Somesensitive - ‘pwd’ !=
• Unix is case
‘pWd’ know
• Unix commands are short
• cp = copy; mv = move; rm = remove
• Unix commands are almost always
lower-case
• Switches come on both upper and
lower-case
• Often have different meanings!
Watch Out!
41
Ctrl+World =
Mwahahaa!!!
• Shortcut sequences are often
denoted as C-?, M-?, and ^?, where
? is some key
• C = Ctrl = ^
• M = Meta ~ Alt ~ Option (on Mac
only)
• You’ll see this often in
documentation, particularly in emacs
docs
42
me outta here!
Let or stopping (by which I mean
• Exiting
using) some programs (by which I mean
vi) can be a challenge
• Some standard exit shortcuts
•C-d : sends EOF to program
•C-c : interrupts the program
•C-\ : exits program causing a core dump
• Programs do not have to obey these
shortcuts, and may map them to another
function.
43
Manna from
Heaven:
• Wouldn’t it Completion
to Tab
be nice if you didn’t have
type /home/OneReallyLongName every
time?
• You can use the tab key to complete
commands and arguments to
commands
• Can complete:
• commands, switches, host names,
directory names, process names,
more
man pages, and 44
Line Editing
• The up arrow key will cycle back
through your command history;
pressing down arrow will cycle
forward
• The left and right arrow keys will
move the position of the cursor so
you can insert new characters
• Backspace and delete work as
expected
45
Line Editing
• C-? will delete back
• C-d will delete forward
• C-u will delete the entire line
• C-k will delete the forward from the
cursor
• C-l clears the terminal
• C-y will paste the characters you have
deleted
46
Line Editing
• C-a will move to the beginning of
the line
• C-e will move to end of the line
• M-b will move back a word
• M-f will move forward a word
• C-_ will undo the last thing typed
• C-r will allow you to search your
command history
47
Are You “Special”?
• The shell interprets a number of
characters as having special
meaning
• Which characters are special?
• #$*?[]()=|^;`$“‘\
• Special characters have many uses
that we will cover through the
course
48
Escape From
• To pass special characters into
\”Reality\”them,
programs you need to escape
precede with a \
• \ disables the special meaning of the
character
• Can also disable meaning through
quoting
• ‘xxx’ - all characters disabled
• “xxx” - all but $, ‘, and \ disabled
• \ can also be used to continue a
49
Finding Help:
• Thecan’t teach yourself everything.
You Larry Page Center for Unix
Admit it, you’re going to need help.
Addicts
• Resources:
• Google - always try Google first
• Websites - freebsd.org,
linuxquestions.org
• Books - Unix Power Tools, FreeBSD
Handbook
• People - Staff and Consultants
• QREFs - Documentation provided by
CS Dept.
50
Damn Sexist
Documentation
• the man pages (women get their own
docs)
• are mostly usage guides
• not general references, guides, etc.
• before asking Google, look here
• info pages
• mainly about emacs
• program docs (shared equally by the
sexes)
51
Getting Mr. Know-
It-All To
• Man Sections Be Useful
• 1 - Commands available to users
• 2 - Unix and C System Calls
• 3 - C Library Routines
• 4 - Devices and Device Drivers
• 5 - File Formats, Protocols
• 6 - Games
• 7 - Conventions, Macros, Text
Processing
• 8 - System Administration
52
If Only Real Men
Had These
Switches
53
Navigating A Man
• You see man output in a pager (by
Page in less)
default more, when fixed
• Arrow keys move page up/down
left/right
• Space bar - pages down a full
screen
• Search using the / key
• / or n moves to next instance of
pattern
• N moves to previous instance
• b key is back/pgup; f key is
54
Working Together
• You have a factory which takes
opplar-wheezers and outputs some
amazing kolp-shaped nern-draped
joggybits.
• You have another factory which
accepts these joggybits, and outputs
plerk-flavored dasser-bravored
fiddlyjinks
• How do you connect the
factories...err programs?
55
Together
Workingruns more than one
• Unix generally
program at a time (running one is
Window’s job)
• Programs are designed to work
together, so they need to communicate
• Use I/O mechanisms known as
standard in, standard out, and standard
error
• By default these either get input from
the command line or output to the
command line 56
Working Together
• Standard In (stdin)
• the characters received as input
• Standard Out (stdout)
• the characters that are real program
output
• Standard Error (stderr)
• the characters being output as part
of any error messages
57
Working Together
• Everything in Unix is a file
• devices, directories, sym-links,
and what you normally think of as
files
• What about stdin, stdout, and stderr?
• What makes a file a “real” file?
58
Working Together
• Are they files? No, are file
descriptors.
• Treated like files, use read() and
write()
• What is read from and written to is
managed by the OS
• So, now how do we manage to get
two programs to talk?
59
Working Together
• We use pipes, which is what std* are
• Data is piped from one program to
another
• To pipe stdout (not stderr) use the ‘|’
character
• % cmdone args... | cmdtwo args...
• Programs used in this way are called
filters
• Learning to use filters is a Unix must
• Writing good filters is even more
important 60
Misdirection for
Redirection of a
• You can also redirect the output
program into a file
• Or redirect a program to read stdin
from a file
• To redirect stdin:
•% command file (may overwrite file)
•% command >> file (appends to file)
61
What about stderr?
• If stderr is not redirected, it will be
printed as normal to the terminal
• To redirect both stdin and stderr:
•% billybob |& bubba
•% homer >& outfile
•% jethro >>& outfile
• To redirect just stderr:
•% marylou 2> errorfile
62
Complexjust file
• Recall that stdin, etc are
Redirection
descriptors
• We can alter where these
descriptors point from the command
line
• stdin = 0, stdout = 1, stderr = 2, free
3 to 9
• Examples:
•2>&1 (points stderr at stdout)
•1>/dev/null (stdout points to oblivion)
•2>&1 1>&2 (what does this do?)
•3>&2 2>&1 1>&3 (what about this?)
63
Back-Tick
The tick is ` (located next to 1
• The back
key)
• If you surround a command in back-
ticks, the shell will replace the
surrounded text with the output of
the command
• Examples:
•% grep cout `ls *.cpp`
•% emacs `grep -l error *.c`
• Back-ticks are most useful in shell
64
You Ought to Know
This By NowHistory
• Aware of Unix Philosophy &
• Users and Groups
• How to Find Help (*hint* use
Google)
• Some (Very) Basic Commands
• Piping, Redirection, and Back-Ticks
• What the Shell Is and Why Its Cool
• A Few Other Tidbits
65
Processes and
Programs
• What is a Program?
• What is a Process?
66
The Kernel
• What Is The Kernel?
• What Does The Kernel Do?
67
Making Forrest Run
• Unix is a multi-user and multi-
tasking system
• Need to be able manage processes
• Modern GUIs mitigate this only a bit
• We’ll assume you have one shell
session and need to be able to run
multiple programs
68
Making Forrest Run
• Have three types of process groups
• Foreground - process(es)
currently receiving keyboard input
• Background - process(es) running,
but not receiving keyboard input
• Suspended - processes that aren’t
running, but have yet to terminate
• Managing the processes in each of
these groups is called “job control”
69
Sending The Right
Signalsby sending it
• You suspend a process
a special signal from the keyboard
• Suspend = C-z = SIGTSTP
• Interrupt = C-c = SIGINT
• Quit = C-\ = SIGQUIT
• These signals are only sent to
processes in the foreground group
• Once you suspend the process,
you’ll go back to the shell
70
Foreground &
• When you type in a command at the
shell it runs in the foreground
• To make it run in the background
type a ‘&’ after the command
•% cmd (running in foreground)
•% cmd & (running in background)
• To go to a suspended or
backgrounded job you use the fg
command
71
Mid-Level
Management
• The jobs command shows which
processes you have running in the
background
• We can then use the fg command to
switch between processes
• Use the bg command to let a suspended
process continue in the background
72
The Process Family
Tree
• Every process on a Unix system has a
parent and can have children
• Children are created with the fork()
system call - creating a child is
known as forking
• Every process is a descendent of init
• Every orphaned process is a child of
init
• A zombie is a process which has
yet
exited but hasn’t 73 been reaped by
Process Ownership
• Each user on the system can own
processes
• Every process must be owned by a
user
• To uniquely identify a process it is
assigned a number - PID (process id)
• To see all of this information about
processes (PID, parent) use the ps
command
74
How To Be Like
• kill kill KILL is the command you
Charlie Manson
want
• To kill a process we generally need
its PID
• Can get PID from either ps or from
top
• top shows bunches of process stats
• What would happen if we typed (as
root)...
•% kill 1 (init’s PID is always 1)
75
• Each process has aPriority
Process priority
• The priority determines how much
time the process will get on the CPU
• Users can’t change a processes
priority, only a superuser and the
kernel can do that
• Users can set the niceness of a
command
• A higher nice value means that the
process is more likely to give up its
own time 76
Useful Programs
77
Useful Programs
78
Useful Programs
79
Useful Programs
80
Useful Programs
81
File Ownership
• Files also follow a security model
• Each file has an owner and a group
• The owner is the user that created
it
• The group is (generally) the
primary group of the user
• Each file has three sets of
permissions
• User, group, and others (everyone
82
File Permissions
• Each file has permissions for read,
write and execute
• Each of these permissions apply to
user, group, and others
• So permissions look like
•rwx | rwx | rwx
•user | group | others
83
Changing
Ownership
• Only the owner and superuser can
change the ownership of a file
•chown
•chgrp
84
Changing File
Permissions:
Why You Can’t touch
her.jpg permissions
• Use chmod to change file
•chmod
85
Special Files:
They ride the system bus
• Directories
• Permissions mean different things
• r - can list contents with ls
• w - can create a file inside
directory
• x - can access a file inside
directory
86
I Can’t See
.deadpeople
• Dot-Files are files with a ‘.’ as the
first character of the file’s name
(geewiz!!)
• You can see these files with ls -a
• Generally contain configuration
information
• Examples: .zshrc, .emacs, .xinitrc
•./ and . : the current directory
•../ and .. : the parent directory
87
~ Sweet ~
• ‘~’ is referred to as a tilde (TILL-day)
• ~ is a shortcut referring to your home
directory
• ~username refers to that users home
directory
• Example:
•~mkegel = /home/mkegel (on knuth)
•~mkegel = /Users/mkegel (on shadow)
88
•A path is either an absolute
or relative path
•Absolute paths begin at /
(root)
•Relative paths begin at the
current working directory
(cwd)
•Example (absolute):
/home/lush/drinks/vodka.tex
~/drinks/vodka.tex
•Example (relative):
./drinks/vodka.tex
../wino/drinks/maddog.tex
drinks/vodka.tex
89
File Links one file,
• A link allows you to refer to
by a name other than what it has
• Ex. Could refer to /billy/joe as
/billy/bob
• When you access /billy/bob the OS
transparently redirects you to /billy/joe
• Can link to both a regular file or to a
directory
• Two types of links: hard-links and
symbolic-links (aka symlinks)
90
Types of Links
• Hard-links
• Cannot refer to a directory
• Cannot cross file systems
• Take up virtually no memory
• Are essentially a different name for the
same file
• Symlinks
• Can do what hard-links cannot
• Are a real file on disk (this can present
91
Creating Links
92
The Glob
• File globs (aka wildcards) allow you to
refer to a group of files whose names
match a specific pattern
• Globs are different than Unix Regexs
• Globing is provided by the shell
• Why is it a good thing (or a bad one)
for globs to be expanded by the shell?
93
•* - matches anything, except dot-files
Standard Globs
•** - search recursively
•*** - search recursively, follow symlinks
•? - matches a single character
•[a-z] - match a single character in the
• specified range
•[^a-z] - match a character NOT in the range
•(x|y|z)- match either x or y or z
•{a,b,c}- expands to a, b, c
94
Unix Directories
• The organization of programs and files
in the Unix Hierarchy is interesting
• Programs are grouped by how critical
they are to the operation of the system
• In general there is a correct location for
programs, libraries, and configuration
files to go
• Whether or not these “rules” are
followed is up to the providers of the
system 95
Not so much rules as
•/home - userguidelines
home directories
•/bin - user critical programs
•/dev - block and character device files
•/etc - system configuration files
•/sbin - system critical programs
•/tmp - temporary files
•/usr - general user programs
•/var - variable length files (log files)
•/lib - shared libraries
•/opt - larger static packages
•/boot - kernel image and other boot files
•/mnt - mount point for devices
96
Some special
• /dev/null devices
• Is a sink for output
• /dev/zero
• Ever want to have an infinite stream of
zeros? Here’s your chance!
• /dev/random and /dev/urandom
•
Both output a random stream of
information
• /dev/random draws from the entropy pool
• /dev/urandom is actually pseudo-random
• /dev/pr0n
• An infinite stream of porn
97
Environment and
Shell Variables
• The shell keeps track of a number of
variables that hold useful information
• Programs that you run from the shell are
able to access these variables
• Env. variables are inherited by all the
shells you may have; shell variables are
local to each instance
• Environment variables are named (by
convention)in all CAPS; shell variables
are lower-case 98
Common Env.
Variables
• Use the printenv and set commands to see
what variables are set and their values
• PATH - directory list searched for commands
• MANPATH - directory list; for man pages
• PS1 and PS2 - your prompt definition
• PAGER - pager used to open man pages
• EDITOR and VISUAL - preferred text editor
• HOSTNAME - name of computer logged in to
• UID and GID - your user and group IDs
99
Setting Env.
Variables
• You use the export command in zsh
to set environment variables
• You can see the value of a specific
variable by using the echo command
100
Setting Env.
Variables
• Zsh reads many different
configuration files, some of them
are:
•~/.zshrc ~/.zprofile ~/.zlogin
• Read through these files!
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• To reduce typing, alias a long and/or
repeated command(s) to a single short
command
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Altering the Default
Permissions
• By default when you create a file,
ALL the rwx permissions are set to
ON
• Your umask sets what permissions
are to be turned OFF
• Some good default umasks: 022, 076
• Some bad default umasks: 755, 701
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su and sudo
• These two programs allow you to execute
programs as a superuser (or another user)
• work by changing your UID and GID
• With su you have to know that users
password
• With sudo you generally use your own
password
• sudo is flexible; su is not
• sudo can control which programs are
executed as which users on which
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Editing /etc/sudoers
• The privileges that sudo grants are
stored in a regular text file (/etc/sudoers)
and is editing by the visudo program
• Basic syntax for an entry is:
• USER HOST = [(RUN_AS_USER)] CMDS
• Some examples:
• joe turing = (root) /sbin/some_cmd
• %group ALL = (root) NOPASSWD: /bin/cmd
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Everything You Always
Wanted to Know About
But
Mounting Drives,drives, Were
• In Unix devices (hard
Afraid managed
cameras, etc.)areto Ask by the
superuser
• Devices are “mounted” at some point
on the file system; they can then be
accessed
• You use the mount command to mount
any type of device - hard drives, usb
devices, etc.
• Improper mounting can leave behind
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devices
• Device nodes are located in /dev
• Linux device names, examples
• hda3 (first hard drive, third
partition)
• sdb2 (SCSI device)
• input/mouse0 (mouse on my
system)
• You always mount a device to a
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mount and umount
• Use these programs to mount and
unmount filesystems (generally need
to be root to do so, however)
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/etc/fstab
• Informs the system of which devices
are hooked up to your system
• Can mount devices at boot (or not),
how they are mounted, other options
• Can automagically mount a device if
the mount point is in /etc/fstab
• DO NOT EVER FUBAR THIS FILE!!
• or you will be unhappy and have to
use ed 109
cron
The Punctual Warrior
• cron - daemon that schedules tasks for
execution
• entries created/modified with the crontab
command
• Can schedule based on:
• mins hrs day-of-month month weekday cmd
• Can specify a single entry, a range, a list, or
give the all wildcard (*) for a specific time-
slot
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• Web Browser - Firefox, Konqueror
• Text Editor - jEdit, emacs, vi
A Better Replacement
• Word Processor - abiword, Open Office
• Spreadsheet - gnumeric, Open Office
• Music Player - xmms, amarok
• Movie Player - vlc, totem, xine, mplayer
• Terminals - eterm, xterm, rxvt, konsole
• Mail - Thunderbird, pine, mutt
• PDF - xpdf, kpdf, gpdf
• FTP - gftp, ncftp, lftp
• CD Burner - k3b
• AIM - gaim, kopete
• Bit Torrent - Azureus
• File Manager - Nautilus, Konqueror
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Other Useful
• WINE - allows you to run many
Programs
Windows executables on Linux
• Cygwin - allows you to run some
Linux programs on Windows
• Samba - lets Linux use Windows
networks
• jEdit, Emacs, vi - powerful text
editors
• Only one thing to know - don’t use
vi
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Regular
Expressions
• The most nifty, and geekifying, Unix
thing ever...
• makes parsing of complicated input
simple, easy, and efficient.
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tr
• Tool to translate characters; like a
global search-and-replace from the
command line
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screen
• Nifty tool that allows you leave
shells open (and programs running)
on which ever machine you’re
logged into
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• I’d likeThank(inyou’s
to thank no particular
order):
•Ran Libeskind-Hadas
•Melissa O’Neill
•Geoff Kuenning
•Mike Erlinger
•Chris Stone
•Titus Winters
•and especially those willing to sit
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