1. CS 240 Programming in C Lecturer: Ramin Dehghanpoor Office: S-3-134
Course:
I got help from and used Dr. Cheung’s and Dr. Liang’s slides

2. Course Objectives This course will teach you C Programming
It also covers several other related topics:
UNIX Commands
Compiler and Debugger
MAKE and Makefiles
UNIX/LINUX File System and File Access

3. Motivation
C is the language of choice for systems programming and embedded systems and it is the mother of all languages.
According to the May 2018 Tiobe Programming Community Index (rate language popularity)
Mastery of the material in this course may enable you to get a high paying job!

4. Introduction Syllabus, Lecture Notes and Schedule Required Textbooks
Web:
Required Textbooks
The C Programming Language, 2nd Ed., Kernighan & Ritchie
LINUX for Programmers and Users, 1st Ed., Glass & Ables

5. Introduction HW assignments Homework is an Individual Effort
Assignment write-ups will be on my website
But HW must be done on our UNIX/LINUX systems!
Must adhere to the C coding standard
Coding Guidelines.pdf
Homework is an Individual Effort
You can answer questions for each other as long as you acknowledge any help that you receive from others
BUT DON’T HAVE OR LET ANYONE ELSE DO YOUR HOMEWORK FOR YOU!
If I discover any cheating, I’ll follow school policy!

6. Introduction to Grading
HW assignments (40%)
7 homework (The highest 6 are counted)
Exams (60%)
3 exams (The highest two are counted)

7. Getting Started UNIX Account
Apply for a CS240 account
in person: see operators in UNIX/PC Lab (S-3-157)
or remotely: see instructions posted in
Access to UNIX systems using PCs in the UNIX/PC Lab or
Access to UNIX systems from your home PC
Secure internet access is required now!
Can not use TELNET or FTP for remote access!
Must use Secure Shell 2 for remote access
Can use Putty or SSH Communications S/W packages

8. Getting Started Putty SSH Communications
Download, UnZIP and Execute Installer as directed
Use Putty configured for SSH2 instead of TELNET
Use PSCP or PSFTP or FileZilla for secure ftp
SSH Communications
Information:
Download from:
Download and Execute Installer as directed

9. Getting Started
You may want to use your own PC as a “front end” to our UNIX systems
This is the way modern SW development environments in industry are set up now
Possible using the SSH Communications secure access software package
Have four windows open on your PC

10. Getting Started Four windows:
Window to local file folder for your source files
Notepad to edit/save a text source file locally
SSH Secure File Transfer (or FileZilla) to transfer the locally stored source file to the UNIX/LINUX system
SSH Secure Shell to run UNIX/LINUX commands
You are on your own to try this on your own PC!
Don’t send problem reports to “operator” for help!

11. Getting Started (Mac and Linux)
Mac and Linux operating systems come built-in with terminal programs which offer a command line.
Use ssh command. Ssh
Example: ssh

12. Communication
You must send me an indicating your preferred address for announcements and lecture schedules. I will communicate with you by that .
Monitor the course website.

13. C Programming
You will learn to write, execute, and debug C language programs in this course
We will spend most of the time in class on the C language, MAKE, and the debugger
This is the primary material for exams
Use Kernighan and Ritchie (K&R) textbook

14. UNIX/LINUX Operating System
You will be using UNIX to (edit,) compile, debug, and run your C programs.
We will not spend as much time in class on UNIX.
You must learn to use UNIX as you go
You will be held accountable for UNIX on exams
Use the Glass and Ables textbook
Also refer to the Basic UNIX Guide posted on the website:

15. Basic UNIX Commands
cat display a file on your terminal screen (see also “more”)
cd change directory
cp copy a file
logout logout from your account
lpr print a hard copy
ln creates a new link to a file
ls list files in a directory
more display a file on your terminal screen - one page at a time
mv move a file from one place to another
mkdir create a new subdirectory
pwd print working directory (pathname of directory you’re in)
rm remove (delete) a file
rmdir remove (delete) a directory
CTRL-c “Control” key and “c” key together – stop current command

16. UNIX File System Directory cd cs240 cd .. pwd Sub-directory ls
~$ pwd  print working directory
/home/ramin
~$ ls  list what is in there
cs240
~$ cd cs240  go to subdirectory
~/cs240$ ls  list what is in there
test.c
cd cs240
cd ..
pwd
Sub-directory ls
Sub-directory
File rm
filename
File
mkdir
New Sub-directory

17. Hidden Files There are hidden files on your home directory
not normally displayed by ls
Names of these files begin with ‘.’, e.g. .login
You can see them if you use ls with –A option
blade64(3)% ls -A
.cshrc plan cs240.f mbox private_stuff
.login cs cs240.old playpen public_html
.msgsrc cs cs playpen2 student
.cshrc is a script file executed when shell is started
.login file is a script file executed at time of login

18. UNIX/LINUX File Permissions
ls –la drwxr-x--- 2 ramin phd 4096 May 26 19:16 cs240 r =read w =write x =execute - =no access Change file permission using the chmod command: chmod o+rx cs240; ls -la drwxr-xr-x 2 ramin phd 4096 May 26 19:20 cs240
directory
User group Others

19. Home Work Assignment #1: Hello World!
Your first homework project is to create and run a C program – “Hello World!” (K&R, p5+)
Create a source file “hello.c” in one of two ways
Use a PC in S-3-157, run Putty/SSH and vi or nano
Use your home PC, run Putty/SSH and vi or nano
Use “gcc” to compile and create a file named “hello”
Run “hello” to see the printout on screen
Run “script” to create a “typescript” file and run “exit” to end the script file
Turn in the “typescript” file for grading

20. Handing in Assignments
Turn in assignments as hard copy of typescript file and also send me your hw files by before deadline.
% script (Start recording typescript file)
Script started, file name is typescript
% ls –la (list directory entries)
% cat hello.c (display source file)
% gcc –m32 hello.c –o hello (compile source file in 32-bit mode)
% ./hello (run executable file from
the current directory)
% exit (stop recording)
script done on Thu Aug 23 11:30:
% lpr typescript (print typescript file at the unix lab)

21. vi or vim Editor (Glass, Pages 82-92)
“vi” is a UNIX visual editor (vim is the LINUX version)
Keyboard oriented – no use of a mouse!
At UNIX prompt, type “vi hello.c”
“vi” opens an existing file / creates a new one
“vi” has three modes (See next slide)
“Command mode”
“Insert mode”
“Last line command mode”

22. Last Line Command Mode:
“vi” Modes
At UNIX prompt,
type “vi [filename] ”
Type “:”
Command Mode:
Type commands or move cursor over text
Last Line Command Mode:
Type “w file” to write file
Type “r file” to read file
Type
“Enter”
Type “i”
Type “I”
Type “a”
Type “A”
Type “o”
Type “O”
Type “R”
(Glass, p. 58)
Type “Esc”
Insert Mode:
Insert text at the current cursor position
Type “q” or “q!” and
to exit vi
(Return to Unix prompt)

23. vi’s Text Entry Mode Commands
Key Action
i Text is inserted in front of the cursor
I Text is inserted at the beginning of the current line
a Text is added after the cursor
A Text is added to the end of the current line
o Text is added after the current line
O Text is inserted before the current line
R Text is replaced (overwritten)

24. “vi” Commands Movement Commands (Glass, page 86)
Up one line “cursor up” or “k” key
Down one line “cursor down” or “j” key
Right 1 char “cursor right” or “l” key
Left 1 char “cursor left” or “h” key
Edit commands (Glass, page 87)
[n]x delete n characters at cursor
[n]dd delete n lines at current line
You can find more vi commands in
For vi to display line numbers by default, create an .exrc file in your home directory that has the following line:
set nu
Then save the .exrc file and exit. Logout and log back in. Your new vi session should show line numbers.

25. hello.c Program(K&R, Page 6)
/* hello: first homework assignment
name: your name
date: xx/xx/xx */
#include <stdio.h>
int main(void) {
printf(“Hello World!\n”);
return 0; }
comment
C preprocessor
directive
C function
statements

26. C Program - Comment Lines
Comment text is ignored by the compiler
/* This is a multi-line comment.
The compiler ignores both lines. */
Be sure to include the closing “*/”.
For example:
/* This is a multi-line comment
int main (void) {
printf (“Hello World!\n”);
return 0;
} /* terminated by this -> */
int main(void) and return is required.

27. C Source - #include …
Because this program uses the Standard I/O Library, it needs to include <stdio.h>
In C programming, a “.h file” defines
Macros (e.g. Names for constants)
Prototypes for functions (e.g. printf itself)
“gcc won’t compile “hello.c” with the “printf” function without the “#include <stdio.h>”

28. C Source – Main Declaration
“int main (void )” is where the UNIX system starts execution of your program
Your program is between the “braces” { }
Braces are usually placed on their own lines {
program statements are here; }

29. C Source - printf
The Standard I/O Library provides you with a function named “printf ( )”
“printf ( )” prints argument as text on screen
Argument is the text between the parentheses (“Hello World!\n”)
“\n” is a C convention for “end of line”
(character constants in K&R page 193)
All C program statements end with a “ ; ”

30. Character Constants New line \n backlash \\
Horizontal tab \t question mark \?
Vertical tab \v single quote \’
Backspace \b double quote \”
Carriage ret \r octal number \ooo
Form feed \f hex number \xhh
Audible alert \a
For example:
\n = \12 = \x0A = newline character