Lecture 1 Introduction sheet Course webpage - PowerPoint PPT Presentation

Lecture 1  Introduction sheet  Course webpage  http://csserver.evansville.edu/~hwang/f10-courses/cs215.html  Handouts, assignments  Supplemental resources  C, C++, Java comparison  Basic Unix  Syllabus and schedule, textbooks  CS Lab and KC-267 Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 1

Outline  What is Unix?  Logging into Linux  Basic Unix commands  Programming using g++  What is C++?  Library headers and namespaces  Constants and types  Console input and output Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 2

What is Unix?  Unix is an operating system that is highly configurable  Linux is an open-source version of Unix.  Ubuntu is a distribution of Linux  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 Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 3

Logging into Linux - Console Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 4

Logging into Linux - Putty Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 5

Basic Unix Commands  Changing passwords - old, new, new again  yppasswd - on UE client machines  passwd - on VirtualBox  Creating (sub) directories (i.e., folders)  mkdir <dir1> <dir2> …  Example: mkdir cs215  Listing directories  ls, ls -l, ls -a, ls -la  Example: ls -l cs215 Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 6

Basic Unix Commands  Changing permissions ("change mode")  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 Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 7

Basic Unix Commands  Changing directories  cd - to home directory, cd <dir>  Path relative to current directory unless starts with /  Examples: cd cs215 , cd /etc  Also, . ("dot" - current), .. ("dot-dot" - parent), ~ ("tilde" - home)  Wildcards  * - 0 or more characters, e.g. project1.*  ? - exactly 1 character, e.g. project?.cpp Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 8

Programming Using g++  Separate text editor - emacs, vim, gedit  C++ source files have extension .cpp  User-defined header files still use .h  Separate compiler - g++  Command line options: -Wall, -o <progname>  Example: g++ -Wall -o hello hello.cpp  ./<progname> is the command to run the program; default program name is a.out  Separate build facility - make Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 9

What is C++?  C++ is a programming language based on C with objects and object-oriented constructs; on- line comparison document  Focus will be on the use of classes to design and implement abstract data types  Minor syntactic differences, for example  Comments can start with // to end of line  Always int main () , never void main ()  No need for void in parameter list Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 10

Library Headers and Namespaces  C++ library headers to not have .h extension  Example: #include <iostream>  C libraries have same name prefixed with 'c'  Example: #include <cmath>  All library names are in namespace std. Prefix names with namespace. E.g. std::cout  Import names with using statements  Example: using namespace std;  Example: using std::cout; Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 11

Constants and types  Use const to define constants (not #define )  Example: const int MAX_SIZE = 80;  Built-in boolean type bool with literals true and false  Example: bool done = false;  Library string type string defined in <string> has =, relops, +. Example: string word1 = "hot", word2 = "dog"; string word3 = word1 + word2; Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 12

Console Input and Output  C++ I/O is done using character stream objects  Console I/O defined in <iostream>  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 Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 13

Console Input and Output  Input streams use extraction operator ( >> )  <input stream> >> <variable>  Skips whitespace  Output streams use insertion operator ( << )  <output stream> << <expression>  Both operators return the left-hand stream operand so that multiple operations may be chained together Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 14

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; Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 15

In-class Exercise  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  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. Wednesday, August 25 CS 215 Fundamentals of Programming II - Lecture 1 16