Lecture 1
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Introduction sheet
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Course webpage
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http://csserver.evansville.edu/~hwang/s11-courses/cs215.html
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Handouts, assignments
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Supplemental resources
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C++, C, Java comparison
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Basic Unix
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Syllabus and schedule, textbooks
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CS Lab and KC-267
Monday, January 10
CS 215 Fundamentals of Programming II - Lecture 1
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Outline
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What is Unix?
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Logging into Linux
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Basic Unix commands
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Programming using g++
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What is C++?
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Library headers and namespaces
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Constants and types
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Console input and output
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What is Unix?
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Unix is an operating system that is highly
configurable
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Linux is an open-source version of Unix
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Ubuntu is a distribution of Linux
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CS Lab and Kc-267 have clients that dual-boot
Ubuntu Linux and Windows 7
Linux clients use csserver.evansville.edu for
login and home directory service
Unix is command-line oriented
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Logging into Linux - Console
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Logging into Linux - Putty
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Basic Unix Commands
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Changing passwords - old, new, new again
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yppasswd - on UE client machines
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passwd - on VirtualBox
Creating (sub) directories (i.e., folders)
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mkdir <dir1> <dir2> …
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Example: mkdir cs215
Listing directories
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ls, ls -l, ls -a, ls -la
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Example: ls ­l cs215
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Basic Unix Commands
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Changing permissions ("change mode")
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chmod <mode> <name1> <name2> …
Mode is three sets (owner, group, world) of three
privileges (read, write, execute)
Represented as 9 bits (r,w,x are 1, - is 0) in octal
(base 8)
Example: rwx­­­­­­ is read, write, execute
privileges for owner only becomes 700
Example: chmod 700 cs215
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Basic Unix Commands
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Changing directories
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cd - to home directory, cd <dir>
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Path relative to current directory unless starts with /
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Examples: cd cs215, cd /etc
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Also, . ("dot" - current), .. ("dot-dot" - parent),
~ ("tilde" - home)
Wildcards
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* - 0 or more characters, e.g. project1.*
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? - exactly 1 character, e.g. project?.cpp
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Basic Unix Commands
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Almost all Unix commands have a "man" (i.e.,
manual) page accessible by the "man"
command.
Examples: man ls, man chmod
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Programming Using g++
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Separate text editor - emacs, vim, gedit
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C++ source files have extension .cpp
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User-defined header files still use .h
Separate compiler - g++
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Command line options: ­Wall, ­o <progname>
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Example: g++ ­Wall ­o hello hello.cpp
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./<progname> is the command to run the
program; default program name is a.out
Separate build facility - make
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What is C++?
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C++ is a programming language based on C
with objects and object-oriented constructs; see
on-line comparison document
Focus will be on the use of classes to design
and implement abstract data types
Minor syntactic differences, for example
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Comments can start with // to end of line
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Always int main (), never void main ()
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No need for void in parameter list
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Library Headers and Namespaces
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C++ library headers to not have .h extension
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C libraries have same name prefixed with 'c'
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Example: #include <iostream>
Example: #include <cmath>
All library names are in namespace std. Prefix
names with namespace. E.g. std::cout
Import names with using statements
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Example: using namespace std;
Example: using std::cout;
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Constants and types
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Use const to define constants (not #define)
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Built-in boolean type bool with literals true
and false
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Example: const int MAX_SIZE = 80;
Example: bool done = false;
Library string type string defined in
<string> has =, relops, +. Example:
string word1 = "hot", word2 = "dog";
string word3 = word1 + word2;
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Console Input and Output
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C++ I/O is done using character stream objects
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Console I/O defined in <iostream>
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cin - ("see-in") input stream connected to keyboard
cout, cerr - ("see-out", "see-err") output streams
connected to screen
endl - ("end-ell") newline with buffer flushing
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Console Input and Output
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Input streams use extraction operator (>>)
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<input stream> >> <variable>
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Skips whitespace
Output streams use insertion operator (<<)
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<output stream> << <expression>
Both operators return the left-hand stream
operand so that multiple operations may be
chained together
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Console I/O Example
int anInt;
double aDouble;
cout << "Enter an integer and "
<< "a double: "
cin >> anInt >> aDouble;
cout << "You entered " << anInt << " and " << aDouble << endl;
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In-class Exercise
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Write a C++ program that asks for two real
numbers and displays which number is the
larger one. E.g., (user input in bold)
Enter two real numbers: 3.4 ­7.3
The larger number is 3.4
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Use a text editor to type in the program and use
g++ to compile the program. Test the program.
When you are confident that it works,
demonstrate it to the instructor.
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