Programming in C
John Samuel
CPE Lyon
Year: 2017-2018
Contact: john(dot)samuel(at)cpe(dot)fr
Goals
- Syntax and fundamentals of programming in C
- Buffer manipulation
- Compilation Chain
Course Structure:
- Classes: 12h
- Practical sessions: 24h
Course:
- Operating system: Linux
- Compilation: gcc
- Editors: Vim, Emacs (or any editor of your choice)
Class:
- Interactive
- Slides: available in French, English
- Questions: Every 20-30 mins
- Final Exam: 60% to grades
Practical Session:
- Grades: 40%
- Project divided into 7 exercises
| Class |
Dates |
| Class 1 |
12th September |
| Class 2 |
13th September |
| Class 3 |
19th September |
| Class 4 |
20th September |
| Class 5 |
26th September |
| Class 6 |
3rd October |
Practical Sessions
- Groups: A, B, C, D
- Pair programming
Give some examples of softwares written in C
C is a
- Imperative (Procedural)
- Structured
- Compiled
programming language.
Note: No classes (Not an object-oriented programming
language!!!)
C
- Developed by Dennis Ritchie, Bell Labs
- First appeared in 1972
/* File: hello1.c
* prints message on the output screen.
* author: John Samuel
* This is a multiline comment
*/
#include
<stdio.h> // headers
// This is a
single-line comment
int main()
{
printf("Hello
World!!!");
return
0;
}
/* File: hello2.c
* prints message on the output screen
using a variable.
* author: John Samuel
* This
is a multiline comment
*/
#include <stdio.h> // headers
int main()
{
int year = 2017;
//variable declaration
printf("Hello World!!! This is year %d", year);
return 0;
}
$ gcc hello1.c
Execution
$./a.out
Hello World!!!
$ gcc -o hello hello2.c
Execution
$./hello
Hello World!!! This is year 2017
Single-line and multi-line comments
// This is a single line comment
/* This is a multi-line
* comment
*/
| Data Type |
C keyword |
Examples |
| characters |
char |
'h', 'a', ... |
| integers |
short, int, long, long long |
...,-1,0,1,... |
| floating point numerals |
float, double, long double |
3.14, 3.14e23 |
| enumeration |
enum |
STUDENT, INTERN |
| C keyword |
Range |
| characters |
signed char, unsigned char |
| integers |
signed short, signed int, signed long, signed long long,
unsigned short, unsigned int, unsigned long, unsigned long long |
Size limits of basic data types are machine-dependent!
char my_char_var = 'a';
Note: See the use of underscores in naming variables
char my_char_var = 'a';
unsigned char my_uchar_var = 234;
short my_short_var = -12;
unsigned short my_ushort_var = 65535;
int my_int_var = 12;
unsigned int my_uint_var = 3456;
long my_long_var = -1234553;
unsigned long my_ulong_var = 234556;
long long my_llong_var = 1123345;
unsigned long long my_ullong_var = 1234567;
float my_int_var = 3.14;
double my_uint_var = 3.14E-12;
long double my_long_var = 3.14E-22;
enumerated data types
enum status {STUDENT, INTERN};
enum status s = STUDENT;
enum status {STUDENT=1, INTERN};
enum boolean {FALSE=0, TRUE};
Note: enum: unsigned int
Finding range of data types using limits.h
| C keyword |
Range |
| signed char |
[SCHAR_MIN, SCHAR_MAX] |
| unsigned char |
[UCHAR_MIN, UCHAR_MAX] |
| C keyword |
Range |
| (signed) short int |
[SHRT_MIN, SHRT_MAX] |
| unsigned short int |
[0, USHRT_MAX] |
| (signed) int |
[INT_MIN, INT_MAX] |
| unsigned int |
[0, UINT_MAX] |
| (signed) long |
[LONG_MIN, LONG_MAX] |
| unsigned long |
[0, ULONG_MAX] |
| (signed) long long |
[LLONG_MIN, LLONG_MAX] |
| unsigned long long |
[0, ULLONG_MAX] |
Finding range of data types using float.h
| C keyword |
Range |
| float |
[FLT_MIN, FLT_MAX] |
| double |
[DBL_MIN, DBL_MAX] |
| long double |
[LDBL_MIN, LDBL_MAX] |
sizeof
sizeof (char) //data type
sizeof (my_uchar_var) //variable
Handling Output
printf("%d",
my_int_var);
printf("%f",
my_float_var);
| C keyword |
Format string |
| char |
c |
| unsigned char |
hhu |
| short |
hd |
| unsigned short |
hu |
| int |
d, i |
| unsigned int |
u |
| long int |
ld |
| unsigned long int |
lu |
| C keyword |
Format string |
| long long int |
lld |
| unsigned long long int |
llu |
| float |
f, F |
| double |
g, G |
| long double |
Lf |
| string of characters |
s |
| Character |
Format string |
| Newline |
\n |
| Tab |
\t |
Binary notation
int
value = 0b10100100;
Octal notation
int
value = 0b10100100;
printf("octal value: %o\n", value);
Hexadecimal notation
int
value = 0b10100100;
printf("hexadecimal value: %x\n", value);
| Operator |
Purpose |
| + |
addition |
| - |
subtraction |
| * |
multiplication |
| / |
division |
| % |
modulus operation |
int
a = 20,
b = 10;
| Operator |
Example |
Result |
| + |
a + b |
30 |
| - |
a - b |
10 |
| * |
a * b |
200 |
| / |
a / b |
2 |
| % |
a % b |
0 |
| Operator |
Purpose |
| < |
less than |
| <= |
less than or equal to |
| > |
greater than |
| >= |
greater than or equal to |
| == |
equal to |
| != |
not equal to |
int
a = 20,
b = 10;
| Operator |
Example |
Result |
| < |
a < b |
0 |
| <= |
a <= b |
0 |
| > |
a > b |
1 |
| >= |
a >= b |
1 |
| == |
a == b |
0 |
| != |
a != b |
1 |
int
a = 20,
b = 0;
| Operator |
Purpose |
Example |
Result |
| ! |
Not |
!a |
0 |
| && |
And |
a && b |
0 |
| || |
Or |
a || b |
1 |
int
a = 20,
b = 0;
| Operator |
Example |
Result |
| a++ |
b = a++ |
a = 21,
b = 20
|
| ++a |
b = ++a |
a = 21,
b = 21
|
| a-- |
b = a-- |
a = 19,
b = 20
|
| --a |
b = --a |
a = 19,
b = 19
|
int
a = 0x01000100;
| Operator |
Purpose |
Example |
Result |
| ~ |
NOT |
~a |
0xffffffbb |
| & |
AND |
a & 0x4 |
0x4 |
| | |
OR |
a | 0x2 |
0x46 |
| ^ |
XOR |
a ^ 0x4 |
0x40 |
| << |
left shift |
a << 1 |
0x88 |
| >> |
right shift |
a >> 1 |
0x22 |
int
a = 20,
b = 0;
| Operator |
Purpose |
Example |
| = |
equal |
a = b |
| += |
addition assignment |
a += b |
| -= |
substraction assignment |
a -= b |
| *= |
multiplication assignment |
a *= b |
| /= |
division assignment |
a /= b |
| %= |
modulo assignment |
a %= b |
Note:
a
op =
b ::-
a
=
a
op
b
| Operator |
Purpose |
Example |
| &= |
bitwise AND assignment |
a &= b |
| |= |
bitwise OR assignment |
a |= b |
| ^= |
bitwise XOR assignment |
a ^= b |
| <<= |
bitwise left shift assignment |
a <<= b |
| >>= |
bitwise right shift assignment |
a >>= b |
Note:
a
op =
b ::-
a
=
a
op
b
if
if (condition) {
...
}
if
int
a = 20,
b = 0;
if (a >
b) {
printf("a is greater than b");
}
if
if (condition1) {
...
} else if (condition2) {
...
} else {
...
}
Note: Non-zero values are considered true-value statements
Note: else is optional
if
int
a = 20,
b = 0;
if (a >
b) {
printf("a is greater than b");
} else if (a <
b) {
printf("a is less than b");
} else {
printf("a is equal to b");
}
Note: Non-zero values are considered true-value statements
switch
switch (expression) {
case value1 : statements1
case value2 : statements2
...
default : statementsn
}
Note: expression must be one of
char,
short,
int or
long
switch
int
a = 20;
switch (a) {
case 10 : statement1
break;
case 20 : statement2
case 30 : statement3
break;
...
default : statementn
}
Note: Both statement2 and statement3 will be executed.
What is the output of the following?
if (1) {
printf("Hi");
} else {
printf("Hello");
}
for
for(initialization;condition;updation){
...
}
for
int
a = 0;
for( a = 0;
a > 10;
a++){
...
}
for
int
a = 0;
for(;
a > 10;
){
...
}
Note: Any or all of initialization, condition or updation statements can be missing.
for
int
a = 0;
for( a = 0;
a > 10;
a++){
...
a += 2 ;
...
}
while
while(condition){
...
}
while
int
a = 20;
while(a > 0){
...
a--;
...
}
while
int
a = 0;
while(a < 20){
...
a++;
...
}
do..while
do{
...
} while(condition);
do..while
int
a = 20;
do{
...
a --;
...
} while(a > 0);
do..while
int
a = 0;
do{
...
a ++;
...
} while(a < 20);
break
do{
...
if (condition1) {
...
break;
}
...
} while(condition);
continue
do{
...
if (condition1) {
...
continue;
}
...
} while(condition);
break
while(condition){
...
if (condition1) {
...
break;
}
...
};
continue
while(condition){
...
if (condition1) {
...
continue;
}
...
};
break
for(initialization;condition;updation){
...
if (condition1) {
...
break;
}
...
};
continue
for(initialization;condition;updation){
...
if (condition1) {
...
continue;
}
...
};
Write a program that prints 0..20 in ascending and descending order
using for, while and do..while.
Write an infinite loop using for, while, do..while.
Arrays
are a collection of homogeneous elements
Matrices
are rectangular arrays
Multi-dimensional arrays
are rectangular arrays
Declaration
char name[20];
Note: C doesn't have a special data type called 'string'.
Declaration
int iarray[20];
float farray[20];
double darray[20];
Initialization
int i;
int array[20];
for ( i = 0;
i < 20; i++) {
array[i] =
i;
}
Initialization
int prices[5] = {
11, 12, 13, 14, 15 };
int rooms[] = {
301, 302, 303 };
char message[] = "Hello World!!";
Note: We didn't specify size of rooms and message.
Initialization
int prices[2][2] = {
{11, 12},
{13, 14}
};
int rooms[][] = {
{201, 202},
{301, 302}
};
char message[2][8] =
{"Hello", "World!!"};
