IntroductionCIS 1057 Fall 2013 1
CIS 1057 Computer Programming in C
Dr. Anwar MamatFall 2013
Acknowledgement: Many slides based on/borrowed from Professor Hugh C. Lauer
Slides include materials from The C Programming Language, 2nd edition, by Kernighan and Ritchie and from C: How to Program, 5th and 6th editions, by Deitel and Deitel)
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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”
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Why?
• Computing and Programming: a life skill for all technical professionals– http://www.youtube.com/watch?
v=dmM_xDzy2nU
• Thinking Computationally: organizing your engineering/scientific/technical thoughts to be amenable to computational solutions
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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
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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, VHDL, System C – semiconductor design• Matlab, SimuLink – physical modeling• LabView – instrumentation and control• Excel – accounting and statistics• SQL – billing and transactions• …
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This Course
• Lectures• C programming language, syntax, semantics, etc.• Common data structures that technical professionals
are likely to need or encounter in C
• Programming Assignments• Write programs to exercise various language
constructs and data structures• Mandatory for passing this course
• Lab Sessions• How to use the system, tools, debuggers, etc.• Practical help from TAs, etc.
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This Course (continued)
• Wednesdays and Fridays, 9:30–10:50 AM• Tuttleman 401B
• Weekly Lab Sessions• Mondays: 8:00 AM - 9:50 AM WCHMAN 104
• Midterm exam• Oct. 18
• Review session prior to exam on Oct. 16
Closed book, one 8½-by-11 sheet of prepared notes, no calculators or electronics
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Prerequisites
• First-level gen-ed math course
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Logistics
• Course web site– http://cis.temple.edu/~anwar/CIS1057Fall2013.html– Blackboard
• Professor’s office Hours– Mondays, 10:00-12:00 AM, or by appointment
(additional hours TBD)– Wachman 414 (215) 204-4207
• Contacts– anwar@ temple.edu
• Teaching assistant– Li, Dawei (TA)
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Required Textbook
• Problem Solving and Program Design in C, 7th Edition, Hanly and Koffman
• Reference book:– The C Programming Language, 2nd edition, by
Brian Kernighan and Dennis Ritchie, Prentice Hall, 1988
Bring to all classes and all lab sessions
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Textbook Outline• 1. Overview of Computers and Programming
• 2. Overview of C
• 3. Top-Down Design with Functions
• 4. Selection Structures: if and switch Statements
• 5. Repetition and Loop Statements
• 6. Pointers and Modular Programming
• 7. Arrays
• 8. Strings
• 9. Recursion
• 10. Structure and Union Types
• 11. Text and Binary File Processing
• 12. Programming in the Large
• 13. Dynamic Data Structures
• Appendix A,B,C,D,E: the C language reference, the standard libraries
• You will use these a lot!
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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.
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Ground Rule #2
• Help each other!
• Even when a project or assignment is specified as individual, ask your friends or classmates 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).
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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
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Temple Academic Honesty Policy
• It is a violation of the Temple Academic Honesty Policy to submit someone else’s work as your own.
• It is not a violation of Temple’s Academic Honesty Policy to ask for help!
• Classmates, TAs, friends, mentors, …
• Explanations of things you don’t understand
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Additional Help
• Academic Resource Center has Tutors available to assist in Wachman 200.
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Questions?
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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
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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 libraries of packages for all kinds of stuff
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Your First C Program
#include <stdio.h>
int main () {
printf(″Hello, World!\n″);
return 0;
}
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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 appendix
• Definition:– “declare”• Introduce an identifier and the kind of entity it refers to• Optionally, define associated memory or program
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So where is printf declared?
#include <stdio.h>
int main () {
printf(″Hello, World!\n″);
return 0;
}
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So where is printf declared?
#include <stdio.h>
int main () {
printf(″Hello, World!\n″);
return 0;
}
Answer: in this file!
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Your First C Program
#include <stdio.h>
int main () {
printf(″Hello, World!\n″);
return 0;
}
• A header file• Contains declarations
of names, functions, data, of things defined elsewhere
• E.g., by the system
• Text of the header file is inserted by compiler into your program
• As if you wrote it yourself!
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Your First C Program
#include <stdio.h>
int main () {
printf(″Hello, World!\n″);
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”
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Your First C Program
#include <stdio.h>
int main () {
printf(″Hello, World!\n″);
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
•{ }
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Your First C Program
#include <stdio.h>
int main () {
printf(″Hello, World!\n″);
return 0;
}
• Call to another function • In this case, a function defined by the system
• Prints some data on standard output
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Your First C Program
#include <stdio.h>
int main () {
printf(″Hello, World!\n″);
return 0;
}
• Argument to printf – a constant string• Enclosed in straight double quotes
• Note the new-line character ′\n′ at the end
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Your First C Program
#include <stdio.h>
int main () {
printf(″Hello, World!\n″);
return 0;
}
• A return statement• return is a reserved word in C
• main should return zero if no error; non-zero if error
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Your First C Program
#include <stdio.h>
int main () {
printf(″Hello, World!\n″);
return 0;
}
• Note that statements typically end with semicolons• So compiler can tell where end of statement is
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Questions?
Write, compile, and execute this program in Lab session
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What happens to your program …
…after it is compiled, but before it can be run?
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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
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Static Linking and LoadingPrintf.c
Printf.o
Librarygcc
ar
Linker
Memory
HelloWorld.c
gcc
HelloWorld.o
Loader
a.out(or name of
your command)
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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 instead of a.out
• gcc –lrt HelloWorld.c• Searches library named rt.a for functions to link
(in addition to standard libraries)
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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
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Questions?