c Program in file input & output

File Handling in c language is used to open, read, write, search or close file. It is used for permanent storage.

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Advantage of File

It will contain the data even after program exit. Normally we use variable or array to store data, but data is lost after program exit. Variables and arrays are non-permanent storage medium whereas file is permanent storage medium.

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Functions for file handling

There are many functions in C library to open, read, write, search and close file. A list of file functions are given below:

No.	Function	Description
1	fopen()	opens new or existing file
2	fprintf()	write data into file
3	fscanf()	reads data from file
4	fputc()	writes a character into file
5	fgetc()	reads a character from file
6	fclose()	closes the file
7	fseek()	sets the file pointer to given position
8	fputw()	writes an integer to file
9	fgetw()	reads an integer from file
10	ftell()	returns current position
11	rewind()	sets the file pointer to the beginning of the file

Mode	Description
r	opens a text file in read mode
w	opens a text file in write mode
a	opens a text file in append mode
r+	opens a text file in read and write mode
w+	opens a text file in read and write mode
a+	opens a text file in read and write mode
rb	opens a binary file in read mode
wb	opens a binary file in write mode
ab	opens a binary file in append mode
rb+	opens a binary file in read and write mode
wb+	opens a binary file in read and write mode
ab+	opens a binary file in read and write mode

1. #include <stdio.h>  
2. main(){  
3.    FILE *fp;  
4.    fp = fopen("file.txt", "w");//opening file  
5.    fprintf(fp, "Hello file by fprintf...\n");//writing data into file  
6.    fclose(fp);//closing file  
7. }  

C program

The C Language is developed for creating system applications that direct interacts to the hardware devices such as drivers, kernals etc.

printf() function

The printf() function is used for output. It prints the given statement to the console.

1.    printf("format string",argument_list);  

The format string can be %d (integer), %c (character), %s (string), %f (float) etc.

scanf() function

The scanf() function is used for input. It reads the input data from the console.

1.    scanf("format string",argument_list); 

 A variable is a name of memory location. It is used to store data. Its value can be changed and it can be reused many times.

It is a way to represent memory location through symbol so that it can be easily identified.

Let's see the syntax to declare a variable:

type variable_name;

Rules for defining variables

• A variable can have alphabets, digits and underscore.
• A variable name can start with alphabet and underscore only. It can't start with digit.
• No white space is allowed within variable name.
• A variable name must not be any reserved word or keyword e.g. int, float etc.

Types of Variables in C

There are many types of variables in c:

1. local variable
2. global variable
3. static variable
4. automatic variable
5. external variable

Types Data Types Basic Data Type int, char, float, double Derived Data Type array, pointer, structure, union Enumeration Data Type enum Void Data Type void Basic Data Types The basic data types are integer-based and floating-point based. C language supports both signed and unsigned literals. The memory size of basic data types may change according to 32 or 64 bit operating system. Let's see the basic data types. Its size is given according to 32 bit architecture. Data Types Memory Size Range char 1 byte −128 to 127 signed char 1 byte −128 to 127 unsigned char 1 byte 0 to 255 short 2 byte −32,768 to 32,767 signed short 2 byte −32,768 to 32,767 unsigned short 2 byte 0 to 65,535 int 2 byte −32,768 to 32,767 signed int 2 byte −32,768 to 32,767 unsigned int 2 byte 0 to 65,535 short int 2 byte −32,768 to 32,767 signed short int 2 byte −32,768 to 32,767 unsigned short int 2 byte 0 to 65,535 long int 4 byte -2,147,483,648 to 2,147,483,647 signed long int 4 byte -2,147,483,648 to 2,147,483,647 unsigned long int 4 byte 0 to 4,294,967,295 float 4 byte double 8 byte long double 10 byte An operator is simply a symbol that is used to perform operations. There can be many types of operations like arithmetic, logical, bitwise etc. There are following types of operators to perform different types of operations in C language. Arithmetic Operators Relational Operators Shift Operators Logical Operators Bitwise Operators Ternary or Conditional Operators Assignment Operator Misc Operator

Category	Operator	Associativity
Postfix	() [] -> . ++ - -	Left to right
Unary	+ - ! ~ ++ - - (type)* & sizeof	Right to left
Multiplicative	* / %	Left to right
Additive	+ -	Left to right
Shift	<< >>	Left to right
Relational	< <= > >=	Left to right
Equality	== !=	Left to right
Bitwise AND	&	Left to right
Bitwise XOR	^	Left to right
Bitwise OR	|	Left to right
Logical AND	&&	Left to right
Logical OR	||	Left to right
Conditional	?:	Right to left
Assignment	= += -= *= /= %=>>= <<= &= ^= |=	Right to left
Comma	,	Left to right

The if statement in C language is used to perform operation on the basis of condition. By using if-else statement, you can perform operation either condition is true or false.

There are many ways to use if statement in C language:

• If statement
• If-else statement
• Nested if

The single if statement in C language is used to execute the code if condition is true. The syntax of if statement is given below:

1. if(expression){  
2. //code to be executed  
3. }  

The if-else statement in C language is used to execute the code if condition is true or false. The syntax of if-else statement is given below:

1. if(expression){  
2. //code to be executed if condition is true  
3. }else{  
4. //code to be executed if condition is false  
5. }  

The if else-if statement is used to execute one code from multiple conditions. The syntax of if else-if statement is given below:

1. if(condition1){  
2. //code to be executed if condition1 is true  
3. }else if(condition2){  
4. //code to be executed if condition2 is true  
5. }  
6. else if(condition3){  
7. //code to be executed if condition3 is true  
8. }  
9. ...  
10. else{  
11. //code to be executed if all the conditions are false  
12. }  

c program

1. Write a Program to check the biggest number between three given integers.
2. Write a Program to check a given character is vowel or consonant?
3. Write a Program to check whether given number is prime or not?
4. Write a Program to check whether given number is perfect number?
5. Write a Program to display all even numbers from 1 to 50.
6. Write a Program to display all prime number from 1 to 100.

7. Write a Program to display the sum of digits of a given number.
8. Write a Program to display whether a given number is palindrome?
9. Write a Program to check whether a given number is armstrong or not?
10. Write a Program to display all the perfect numbers from 1 to 100.
11. Write a Program to display all the armstrong number from 100 to 200?
12.Write a Program to display the maximum and minimum number from a given 10 numbers.

Series

Write a program print series.
1. 1 3 6 10 15
2. 2 4 7 11  16



void main()
{
int i,j=1;//same java,c,c++
for(int i=1;i<=5;i++)
{
j=j+i;
printf("%d",j);//c program
System.out.println(j);//java
cout<<j;//c++
}


}
2.
void main()
{
int i,j=0;//same java,c,c++
for(int i=1;i<=5;i++)
{
j=j+i;
printf("%d",j);//c program
System.out.println(j);//java
cout<<j;//c++
}


}

tree in c

#include<stdlib.h>
#include<stdio.h>

struct bin_tree {
int data;
struct bin_tree * right, * left;
};
typedef struct bin_tree node;

void insert(node ** tree, int val)
{
    node *temp = NULL;
    if(!(*tree))
    {
        temp = (node *)malloc(sizeof(node));
        temp->left = temp->right = NULL;
        temp->data = val;
        *tree = temp;
        return;
    }

    if(val < (*tree)->data)
    {
        insert(&(*tree)->left, val);
    }
    else if(val > (*tree)->data)
    {
        insert(&(*tree)->right, val);
    }

}

void print_preorder(node * tree)
{
    if (tree)
    {
        printf("%d\n",tree->data);
        print_preorder(tree->left);
        print_preorder(tree->right);
    }

}

void print_inorder(node * tree)
{
    if (tree)
    {
        print_inorder(tree->left);
        printf("%d\n",tree->data);
        print_inorder(tree->right);
    }
}

void print_postorder(node * tree)
{
    if (tree)
    {
        print_postorder(tree->left);
        print_postorder(tree->right);
        printf("%d\n",tree->data);
    }
}

void deltree(node * tree)
{
    if (tree)
    {
        deltree(tree->left);
        deltree(tree->right);
        free(tree);
    }
}

node* search(node ** tree, int val)
{
    if(!(*tree))
    {
        return NULL;
    }

    if(val < (*tree)->data)
    {
        search(&((*tree)->left), val);
    }
    else if(val > (*tree)->data)
    {
        search(&((*tree)->right), val);
    }
    else if(val == (*tree)->data)
    {
        return *tree;
    }
}

void main()
{
    node *root;
    node *tmp;
    //int i;

    root = NULL;
    /* Inserting nodes into tree */
    insert(&root, 9);
    insert(&root, 4);
    insert(&root, 15);
    insert(&root, 6);
    insert(&root, 12);
    insert(&root, 17);
    insert(&root, 2);

    /* Printing nodes of tree */
    printf("Pre Order Display\n");
    print_preorder(root);

    printf("In Order Display\n");
    print_inorder(root);

    printf("Post Order Display\n");
    print_postorder(root);

    /* Search node into tree */
    tmp = search(&root, 4);
    if (tmp)
    {
        printf("Searched node=%d\n", tmp->data);
    }
    else
    {
        printf("Data Not found in tree.\n");
    }

    /* Deleting all nodes of tree */
    deltree(root);
}

Introduction to C Language

C is one of the most popular computer language developed at AT&T’S Bell laboratories of USA in 1972 .It was developed by Dennis Ritchie. It is also called mid level language.

Today when the computer technology is on it's highest era and the advance programming languages like C++,C# and JAVA is very popular among developers many of us may think that C is now become less important. But this is not true since, C is still very popular and important language for it's following features.

Advantage Associated with C Language

1. Simple to use and understand. You can later on migrate to C++, C# or java. Hence, preferring two-step learning process.
2. C++,C# or java using oops technology that actually require core C language element.
3. Operating system like window, Linux, UNIX is still written in C. And so if you are to extend any of above operating system to work with new devices you must need to write device driver program. And are exclusively written in C.
4. C has best performance record. Because of highest execution among all other language (due to its verity of data type and powerful operator).
5. Enormous electronic gadgets like mobile phone, digital camera, I-pod, microwaves, ovens, washing machine are using a microprocessor (chip) which contains an operating system and a program which are embedded in these devices which must have fast execution within limited amount of memory. And it is C who comes to show its smartness here.
6. Professional 3D computer game like spaceship and firing bullet need speed to match player’s inputs and C is again hero here.
7. Its structured, high level, machine independent language that provide programmer a freedom to portability facility.(One computer to another).
8. C compilers combine the facility of an assembly language plus high level language. And hence capable to write both operating system and business pack. Many C compilers are itself written in C that is available in market.
9. Another very important feature of C is its ability to extend itself .We can continuously add our own function to its library is convents.

Disadvantages Associated with C Language

1. There is no strict type checking (for ex: we can pass an integer value for the floating data type).
2. As the program extends it is very difficult to fix the bugs.
3. There is no runtime checking.

Basic Structure of C program

Documentation Section
Link Section
Definition Section
Global Declaration Section
-----------------------------------------------------------------
main function section
{
//Declaration part
//Executable part
}
-----------------------------------------------------------------
Sub program section
Function 1
Function 2
--
-- //user defined function
--
Function n