CS-2301, System Programming for Non-majors

IntroductionCS-2301 B-term 2008 1

CS-2301, System Programming forNon-majors

Hugh C. LauerAdjunct Professor

(Slides include materials from The C Programming Language, 2nd ed., by Kernighan and Ritchie and from C: How to Program, 5th ed., by Deitel and Deitel)


Course Objectives

• C language programming• Designing, implementing, debugging, etc.

• How the hardware executes C programs• … and other kinds of programs

• Preparation for computational challenges of engineering, scientific, and other professions

• Preparation for upper-level courses in computing• “Thinking computationally”


Why?

• Computing and Programming: a life skill for all technical professionals

• Thinking Computationally: organizing your engineering/scientific/technical thoughts to be amenable to computational solutions


Why C?

• Because we have to!

• Many situations outside of CS where it is only language or system available

• Small, embedded systems, instrumentation, etc.

• Many “low-level” situations that don’t have support for “high-level” languages

• Operating systems, real-time systems, drivers


Why not C?

• C is very low-level• Data structures must be programmed “by hand”• Operations must be done out in “long hand”• No support for “object oriented” design• Marginal support for higher-level thought processes

• Better alternatives available for technical applications

• Verilog, System C – semiconductor design• Matlab, SimuLink – physical modeling• LabView – instrumentation and control• Excel – accounting and statistics• SQL – billing and transactions• …


This Course

• Mondays & Thursdays, 3:00–4:50 PM• Goddard 227

• Weekly Lab Sessions• B01 – Salisbury 123, Wednesdays 11:00–11:50 AM• B02 – Higgins 230, Wednesdays 1:00–1:50 PM

• Three exams (one hour each)• November 13• December 1 or December 4• December 18

• Review session prior to exam on same day


Prerequisites

• CS-1101 or CS-1102• Or other “first” programming course

• Background survey

• Note: credit may not be earned for both CS-2301 and CS-2303


Logistics

• Course web site– http://www.cs.wpi.edu/~cs2301/b08

• Professor’s office Hours– Mondays and Thursdays, 1:30 PM, or by appointment– Fuller 137:– (508) 831-5493

• Contacts– <Professor’s last name> @ cs.wpi.edu

• Class e-mail lists– cs2301-all or cs2301-staff @ same domain– myWPI for announcements, class bulletin board

• Teaching assistants– Rabin Karki (TA) – Thangam V. Seenivasan (TA)– Brian Bates (SA)

http://www.cs.wpi.edu/~cs2301/b08


Required Textbook

• The C Programming Language, 2nd edition, by Brian Kernighan and Dennis Ritchie, Prentice Hall, 1988

Bring to all classes and all lab sessions


Textbook Outline

• Chapter 1: a tutorial aimed at people who already know how to program

• Chapters 2-8: description of C language• Slightly different order from Chapter 1

• Appendix A: the C language reference• Official definition of language is here!

• Appendix B: the standard libraries• You will use these a lot!


Ground Rule #1

• There are no “stupid” questions.

• It is a waste of your time and the class’s time to proceed when you don’t understand the basic terms.

• If you don’t understand it, someone else probably doesn’t it, either.


Ground Rule #2

• Help each other!

• Even though a project or assignment is specified as individual, ask your friends/colleagues about stuff you don’t understand.

• It is a waste of your time try to figure out some obscure detail on your own when there are lots of resources around.

• When you have the answer, write it in your own words (or own coding style)

Names and Faces

• It is in your own interest that I know who you are.

• Students who speak up in class usually get more favorable grades than those who don’t

• When speaking in class, please identify yourselves



WPI Academic Honesty Policy

• It is a violation of the WPI Academic Honesty Policy to submit someone else’s work as your own.

• It is not a violation of WPI’s Academic Honesty Policy to ask for help!

• Classmates, TAs, friends, mentors, …

• Explanations of things you don’t understand

Additional Help

• Academic Resource Center has Tutors available to assist in CS 2301.

• The schedule is posted and copies are available on the door of the M*A*S*H room and Tutor Center, Daniels Hall, 1st floor.



Instructor — Hugh C. LauerHalf-time Professor

• Ph. D. Carnegie-Mellon, 1972-73– Dissertation “Correctness in Operating Systems”

• Lecturer: University of Newcastle upon Tyne, UK• Approximately 30 years in industry in USA• Research topics

– Operating Systems– Proofs of Correctness– Computer Architecture– Networks and Distributed Computing– Real-time networking– 3D Volume Rendering– Surgical Simulation and Navigation– …


Systems Experience

• IBM Corporation• University of Newcastle• Systems Development Corporation• Xerox Corporation (Palo Alto)• Software Arts, Inc.• Apollo Computer• Eastman Kodak Company• Mitsubishi Electric Research Labs (MERL)• Real-Time Visualization

• Founded and spun out from MERL• Acquired by TeraRecon, Inc.

• SensAble Technologies, Inc.• Dimensions Imaging, Inc. (new start-up)


Experience (continued)

• CTO, Chief Architect of VolumePro™ 1000• World’s first interactive 3D rendering engine for CT, MRI,

seismic scans for PC-class computers• 7.5-million gate, high-performance ASIC• 109 illuminated graphical samples per second

• Two seminal contributions to computer science• Duality hypothesis for operating systems (w/Roger Needham)• First realization of opaque types in type-safe languages (with

Ed Satterthwaite)

• 21 US patents issued• Computer architecture• Software reliability• Networks• Computer graphics & volume rendering


My Other Job

• System for detecting positions of surgical instruments relative to patients’ bodies

• Embedded, real-time system• Detect phase angles from transmitted microwaves

• Convert into positions and orientations of objects

• Programmed in LabView• A graphical, object-oriented, data-flow language


Questions?


The C Language

• First created to develop Unix – late 1960s• Kernighan & Ritchie, 1st edition – 1978

• ANSI C – 1988• Kernighan & Ritchie, 2nd edition, 1988• Implemented by nearly all C compilers

• C95, C99• Minor additions (to be noted as we get to them)• Most major C compilers


Successors to C

• C++• Developed by Bjarne Stroustrup at Bell Labs

• Major extension of C to support object-oriented programming

• Attempted to preserve syntax and structure of C

• Java• Rewrite of C++ at Sun Microsystems

• Machine independence, portability

• Ability to embed in web pages

• Huge support library for all kinds of stuff


Your First C Program

#include <stdio.h>

int main () {

printf(“Hello, World!\n”);

return 0;

}

Fundamental Rule in C

• Every identifier must be declared before it can be used in a program

• Definition:– “identifier”• A sequence of letters, digits, and ‘_’• Must begin with a letter or ‘_’• Case is significant

– Upper and lower case letters are different

• Must not be a “reserved word” — see p. 192

• Definition:– “declare”• Specify an identifier and the kind of entity it refers to• Optionally, define associated memory or program



So where is printf declared?

#include <stdio.h>

int main () {


return 0;

}


So where is printf declared?

#include <stdio.h>

int main () {


return 0;

}

Answer: in this file!



#include <stdio.h>

int main () {


return 0;

}

• A header file• Contains definitions of

names, functions, data, of things declared elsewhere

• E.g., by the system

• Text of the header file is inserted by compiler into your program

• As if you wrote it yourself!



#include <stdio.h>

int main () {


return 0;

}

• A function declaration• Declares the name and

defines the body of your function

• May take arguments, returns an integer

• main is a special name to the system

• The place where a program “starts”



#include <stdio.h>

int main () {


return 0;

}

• Body of the function• Defines what the

function “does”• Sequence of

statements• Each does a step of the

function

• Enclosed in curly brackets

•{ }



#include <stdio.h>

int main () {


return 0;

}

• Call to another function • In this case, a function defined by the system

• Prints some data on standard output



#include <stdio.h>

int main () {


return 0;

}

• A constant string• Note the new-line character ‘\n’ at the end



#include <stdio.h>

int main () {


return 0;

}

• A return statement• return is a reserved word in C

• main should return zero if no error; non-zero if error



#include <stdio.h>

int main () {


return 0;

}

• Note that statements typically end with semicolons• So compiler can tell where end is


What happens to your program …

…after it is compiled, but before it can be run?


Example

#include <stdio.h>

int main () {

printf (“Hello, world\n”)

}

• Symbol defined in your program and used elsewhere

•main

• Symbol defined elsewhere and used by your program

•printf


Static Linking and LoadingPrintf.c

Printf.o

StaticLibrary

gcc

ar

Linker

Memory

HelloWorld.c

gcc

HelloWorld.o

Loader

a.out(or name of

your command)


Compiling Your Program

• gcc HelloWorld.c• Compiles the program in HelloWorld.c, links with

any standard libraries, puts executable in a.out• You should find HelloWorld.o in your directory

• gcc –o hello_world HelloWorld.c• Same as above, but names the executable file hello_world

• gcc –lrt HelloWorld.c• Searches library named rt.a for functions to link


Compiling Your Program (continued)

• gcc foo.c bar.c help.c• Compiles the programs foo.c, bar.c, and help.c,

links with standard libraries, executable in a.out• You should find foo.o, bar.o, and help.o in your

directory

• gcc –o Lab2 foo.c bar.c help.c• Same as above, but names the executable file Lab2

• gcc –c foo.c bar.c help.c• Compiles foo.c, bar.c, and help.c to foo.o, bar.o, and help.o but does not link together


Questions?


Short Break

Please fill out survey questionnaire

CS-2301, System Programming for Non-majors

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