c basics

1. Introduction to ‘C’
P. Madhu Sudhana Rao
Embedded Software Developer
Presented by:
CLASS - 1

2. INDEX OF CONTENTS
• History of ‘C’
• Characteristics of ‘C’
• Structure of ‘C’
• Environment of ‘C’
• Elements of ‘C’
• How to Install Turbo C?
• How to Install GCC?

3. History of ‘C’

4. How it is evolved?
• Dennis Ritchie in 1970 at Bell Labs.
• UNIX Operating System.

5. Characteristics of ‘C’

6. Features of ‘C’
• Middle Level Language.
• Application Programs & System Programs.
• Small Language with 32 English words.
• Library Functions.
• Language is Extendible.
• Structured Program.

7. Structure of ‘C’

8. C PROGRAM
• Comment Section
• Preprocessor Section
• Global Declarations Section
• Main Section
• Local Declarations Section
• Logical Blocks
• Functions
• Local Declarations Section
• Logical Blocks
// C DEMO
#include<stdio.h>
#include<conio.h>
int a;
Void main()
{
char b;
------------------------------
-------------------------------
}
Func1()
{
int c;
----------------------------------
----------------------------------
}

9. COMMENTS SECTION
• Comments are programmer friendly.
• Compiler will never execute comments.
• Two types of Comments
– Single Line Comment
• Syntax: // ……………….
– Multiple Line Comment
• Syntax: /* ………………………….
………………………….*/

10. PREPROCESSOR SECTION
• C PRE PROCESSOR
• Directives
• #include, #define etc…
• How to define constant value
– Syntax: #define mad 2.2
• How to include library file
– Syntax: #include <HedarFile.h>

11. DECLARATION SECTION
• Scope
• Two Sections
– Global Declaration
• Syntax: Data_Type Variable_name;
– Local Declaration
• Syntax: Data_Type Variable_name;

12. Later ….
Functions, Logical Blocks can be discussed later
and nothing to worry at this point of time.

13. Environment of ‘C’

14. COMPILATION PROCESS
SOURCE CODE
PRE PROCESSOR
COMPILER
ASSEMBLER
LINKER
EXECUTABLE CODE
EXPANDED CODE
ASSEMBLY CODE
OBJECT CODE
OTHER OBJECT FILES
LIBRARIES

15. Two Compilers
• Download Turbo C from Google Drive.
• Download Code Blocks from Google Drive.
Follow the PRESENTATION…
In the practical session, download and install them

16. ELEMENTS OF ‘C’

17. BASIC ELEMENTS
• Character Set
• Keywords
• Identifiers
• Data Types
• Constants
• Variables
• Expressions
• Statements
• Comments

18. CHARACTER SET
• Alphabets [a-z, A-Z]
• Digits [0 – 9]
• Escape Sequences
ESCAPE SEQUENCE MEANING
b BACKSPACE
a ALERT
r CARRIAGE RETURN
n NEWLINE
0 NULL
t HORIZONTAL TAB
BACKSLASH

19. KEYWORDS
• Lowercase
• 32 Keywords in ‘C’
auto; break; case; char; const; continue;
default;do;double;else;enum;extern;float;for;
goto;if;int;long;register;return;short;signed;
sizeof;static;struct;switch;typedef;union;
unsigned;void;volatile;while

20. IDENTIFIERS
• Words  Keywords or Identifiers
• Rules:
– The name should consist of alphabets, digits and underscore sign.
– First character should be an alphabet or underscore.
– The name should not be a keyword.
– Since C is case sensitive, the upper case and lower case are different.
– An identifier name may be arbitrarily long.
• Only 8 preferable and upto 31.
5bc int rec# avg no

21. DATA TYPES
• Memory Allocation
• Four Fundamental
– int, char, float, double
• Size Qualifiers
– short, long
• Sign Qualifiers
– signed, unsigned

22. BASIC DATA
TYPE
DATA TYPE SIZE RANGE
char char or signed char 1 -128 to 127
unsigned char 1 0 to 255
Int int or signed int 4 -2147483648 to +2147483647
unsigned int 4 0 to 4294967295
Short int or signed short
int
2 -32768 to +32767
Unsigned short int 2 0 to 65535
Long int or signed long int 4 -2147483648 to +2147483647
Unsigned long int 4 0 to 4294967295
float float 4 3.4E-38 to 3.4E+38
double double 8 1.7E-308 to 1.7E+308
long double 10 3.4D-4932 to 1.1E+4932
32-BIT MACHINE DATA TYPES

23. CONSTANTS
• Can’t be changed throughout the execution
• 3 Types of Constants
– Numeric Constants
• Integer Constants
• Real Constants
– Character Constants
– String Constants

24. VARIABLES
• Store a value
• Declaration of Variables
– Syntax: int x;
• Initialization of Variables
– Syntax: int x=5;

25. EXPRESSIONS
• Arithmetic Expressions
– Syntax: x+y;
• Relational Expressions
– Syntax: a>b;
• Logical Expressions
– Syntax: a==b;
• Function Calls
– Syntax: func(a,b);

26. STATEMENTS
• Expression Statements [x=5, x=y-z]
• Compound Statements [x*y*z+y*z+z*x]
• Selection Statements [if, if…else,switch]
• Iterative Statements [for, while, do…while]
• Jump Statements [goto, continue, break, ret]
• Label Statements [case, default, goto label]

27. COMMENTS
• Increases the readability of a program.
• Write anywhere in the program.
• Comments can’t be nested.
• Can’t be written inside string constant or a
character constant.

28. QUERIES

30. CONTACT
P. Madhu Sudhana Rao
Embedded Software Developer
Orange Research Labs
@: msr@orangeresearchlabs.com
WWW: madresearch.wordpress.com

31. I/O, OPERATORS in ‘C’
P. Madhu Sudhana Rao
Embedded Software Developer
Presented by:
CLASS - 2

32. INDEX OF CONTENTS
• Conversion Specifications
• Reading Input Data
• Writing Output Data
• getchar() and putchar()
• Operators
• Types
• Precedence and Associativity of Operators

33. CONVERSION SPECIFICATIONS

34. %
• %C Single Character
• %d Decimal Integer
• %f  Floating Point Number
• %o  Octal Integer
• %x  Hexa Decimal Integer
• %s  String
• %u  Unsigned Decimal Integer

35. READING INPUT DATA

36. SCANF ()
• Used to read the data.
• Minimum no of Arguments: 2
• Returns the no of variables read.
Syntax:
scanf(“control string”, add1, add2…);

37. WRITING OUTPUT DATA

38. PRINTF ()
• Used to write the data.
• Minimum no of arguments: 1
• Returns the no of characters printed.
Syntax:
printf(“control string”, variable1, variable2…);

39. Getchar () and Putchar()
• To read a character, then get
Syntax: ch=getchar();
• To write a character, then put
Syntax: putchar(ch);

40. OPERATORS

41. Types of Operators
• Arithmetic Operators
• Assignment Operators
• Increment and Decrement Operators
• Relational Operators
• Logical Operators
• Conditional Operators
• Comma Operators
• sizeof Operators
• Bitwise Operators

42. Arithmetical Operators
• Unary Arithmetic Operators
• Binary Arithmetic Operators
Examples [Unary]: +x, -y
Examples [Binary]: +, -, *, /, %

43. Assignment Operators
• Storing of a value.
• Left Hand Side: Variable.
• Right Hand Side: Value.
Examples:
X=8, s=x+y-2, y=x
X+=5 [+= Compound Assignment Operator]

44. Increment and Decrement
Operators
• Increment (++)
• Decrement (--)
• Prefix
• Postfix

45. Relational Operators
• Comparison
• <, <=, >, >=, ==, !=

46. Logical or Boolean Operators
• AND (&&), OR (||), NOT (!)

47. Conditional Operators
• ?:
• TestExpression?Expression1:Expression2
• True  Expression1
• False  Expression2

48. Comma Operator
• Comma separates the expressions.

49. sizeof Operator
• Sizeof is an unary operator.
Syntax: sizeof(variable);

50. Bitwise Operators
• Bitwise AND (&),
• Bitwise OR (|),
• One’s Complement (~),
• Bitwise Left Shift (<<),
• Bitwise Right Shift (>>),
• Bitwise XOR (^)

51. Associativity of Operators

52. Operators Associativity
::a a::b left to right
a() a[b] a->b a[b..c] ({}) ([]) (<>) left to right
a++ a-- left to right
!a ~a (type)a ++a --a right to left!
a*b a/b a%b left to right
a+b a-b left to right
a>>b a<<b left to right
a>b a>=b a<b a<=b left to right
a==b a!=b left to right
a&b left to right
a^b left to right
a|b left to right
&& left to right
|| left to right
a?b:c right to left
= += -= *= /= %= <<= >>= &= |= ^=
right to left
@a right to left
, left to right

53. Examples
This expression is evaluated in this order
1+2*2 1+(2*2)
1+2*2*4 1+((2*2)*4)
(1+2)*2*4 ((1+2)*2)*4
1+4,c=2|3+5 (1+4),(c=(2|(3+5)))
1 + 5&4 == 3 (1 + 5) & (4 == 3)
c=1,99 (c=1),99
!a++ + ~f() (!(a++)) + (~(f()))
s == “mad" || i < 9 (s == “mad") || (i < 9)
r = s == “mad" r = (s == “mad")

54. QUERIES

56. CONTACT
P. Madhu Sudhana Rao
Embedded Software Developer
Orange Research Labs
@: msr@orangeresearchlabs.com
WWW: madresearch.wordpress.com