C++ Programming Code Examples
C++ > File Manipulation Code Examples
Spliter - This Program Will Split And Join Any File
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/* Spliter - This Program Will Split And Join Any File */
#include<stdio.h>
#include<iostream.h>
#include<process.h>
#include<conio.h>
#include<io.h>
#include <fcntl.h>
struct s
{
unsigned long char c;
}
data;
int main()
{
char name[40],filename[40],ans;
long double size=0,i=0,j,parts,loop,mod=0,mod1=0,option,counter=0;
unsigned int handel,st=0;
long int status=0,whrex,whrey;
FILE *fp,*fp1;
cout<<" Welcome To The File Spliter Programe
";
cout<<"1. Split A File
2. Join A File
Enter Your Option ";
cin>>option;
if(option==1)
{
cout<<"
Enter The Path Of The File Which Is To Be Splited
";
gets(name);
fp=fopen(name,"rb");
if(fp==NULL)
{
cout<<"
Cannot Open The Source File ------> Press Any Key To
Exit.......
";
getch();
exit(1);
}
cout<<"
Please Wait ---------------> WHILE FILE BEING ANALYSED
.........
";
while(fread(&data,sizeof(data),1,fp)>0)
{
size++;
}
handel=open(name,O_CREAT);
cout<<"
The Size Of The File Is "<<filelength(handel)<<" BYTES
";
mod=size-1;
rewind(fp);
status=size/100;
cout<<"
Enter The Parts In Which File Is To Be Splited
";
cin>>parts;
loop=size/parts;
for(i=1;i<=parts;i++)
{
cout<<"
Enter The "<<i<<" Target File Name
";
gets(filename);
fp1=fopen(filename,"wb");
if(fp1==NULL)
{
cout<<"
Cannot Open Target File Name ------> Press Any Key To
Exit.......
";
getch();
exit(1);
}
cout<<"
Please Wait ......................
";
whrex=wherex();
whrey=wherey();
for(j=1;j<=loop;j++)
{
fread(&data,sizeof(data),1,fp);
mod1++;
counter++;
if(counter==status)
{
st++;
gotoxy(50,15);cout<<"completion status.... "<<st<<" %
";
counter=0;
}
if(mod1!=mod)
{
fwrite(&data,sizeof(data),1,fp1);
}
}
gotoxy(whrex,whrey+1);
fclose(fp1);
}
fclose(fp);
cout<<"
File Spliting Completed Press Any Key To Exit";
getch();
}
if(option==2)
{
cout<<"
Enter The Name Of The Target File
";
gets(name);
fp=fopen(name,"wba");
if(fp==NULL)
{
cout<<"
Cannot Open Target File ------> Press Any Key To
Exit.......
";
getch();
exit(1);
}
do
{
i++;
cout<<"
Enter The Name Of The "<<i<< " File
";
gets(filename);
fp1=fopen(filename,"rb");
if(fp1==NULL)
{
cout<<"
Cannot Open Source File ------> Press Any Key To
Exit.......
";
getch();
exit(1);
}
cout<<"
Please Wait ......................
";
while(fread(&data,sizeof(data),1,fp1)>0)
{
fwrite(&data,sizeof(data),1,fp);
}
fclose(fp1);
cout<<"
Do You Want To Join Another File (y/n)
";
cin>>ans;
}while(ans=='y');
fclose(fp);
handel=open(name,O_CREAT);
cout<<"
The Size Of The File Is "<<filelength(handel)<<" BYTES
";
cout<<"
Joining Of Files Completed Press Any Key To Exit ";
getch();
exit(1);
}
return 0;
}
Return length of string. Returns the length of the string, in terms of bytes. This function is used to find the length of the string in terms of bytes. This is the actual number of bytes that conform the contents of the string , which is not necessarily equal to the storage capacity. This is the number of actual bytes that conform the contents of the string, which is not necessarily equal to its storage capacity. Note that string objects handle bytes without knowledge of the encoding that may eventually be used to encode the characters it contains. Therefore, the value returned may not correspond to the actual number of encoded characters in sequences of multi-byte or variable-length characters (such as UTF-8).
The sizeof() is an operator that evaluates the size of data type, constants, variable. It is a compile-time operator as it returns the size of any variable or a constant at the compilation time. The size, which is calculated by the sizeof() operator, is the amount of RAM occupied in the computer. The sizeof is a keyword, but it is a compile-time operator that determines the size, in bytes, of a variable or data type. The sizeof operator can be used to get the size of classes, structures, unions and any other user defined data type. The data_type can be the data type of the data, variables, constants, unions, structures, or any other user-defined data type.
Write block of data. Inserts the first n characters of the array pointed by s into the stream. This function simply copies a block of data, without checking its contents: The array may contain null characters, which are also copied without stopping the copying process. Internally, the function accesses the output sequence by first constructing a sentry object. Then (if good), it inserts character into its associated stream buffer object as if calling its member function sputc until n characters have been written or until an insertion fails (in this case it sets the badbit flag). Finally, it destroys the sentry object before returning.
#include is a way of including a standard or user-defined file in the program and is mostly written at the beginning of any C/C++ program. This directive is read by the preprocessor and orders it to insert the content of a user-defined or system header file into the following program. These files are mainly imported from an outside source into the current program. The process of importing such files that might be system-defined or user-defined is known as File Inclusion. This type of preprocessor directive tells the compiler to include a file in the source code program.
Read block of data. Extracts n characters from the stream and stores them in the array pointed to by s. This function simply copies a block of data, without checking its contents nor appending a null character at the end. If the input sequence runs out of characters to extract (i.e., the end-of-file is reached) before n characters have been successfully read, the array pointed to by s contains all the characters read until that point, and both the eofbit and failbit flags are set for the stream. Internally, the function accesses the input sequence by first constructing a sentry object (with noskipws set to true). Then (if good), it extracts characters from its associated stream buffer object as if calling its member functions sbumpc or sgetc, and finally destroys the sentry object before returning.
In computer programming, loops are used to repeat a block of code. For example, when you are displaying number from 1 to 100 you may want set the value of a variable to 1 and display it 100 times, increasing its value by 1 on each loop iteration. When you know exactly how many times you want to loop through a block of code, use the for loop instead of a while loop. A for loop is a repetition control structure that allows you to efficiently write a loop that needs to execute a specific number of times.
Check whether eofbit is set. Returns true if the eofbit error state flag is set for the stream. This flag is set by all standard input operations when the End-of-File is reached in the sequence associated with the stream. Note that the value returned by this function depends on the last operation performed on the stream (and not on the next). Operations that attempt to read at the End-of-File fail, and thus both the eofbit and the failbit end up set. This function can be used to check whether the failure is due to reaching the End-of-File or to some other reason.
The cin object is used to accept input from the standard input device i.e. keyboard. It is defined in the iostream header file. C++ cin statement is the instance of the class istream and is used to read input from the standard input device which is usually a keyboard. The extraction operator(>>) is used along with the object cin for reading inputs. The extraction operator extracts the data from the object cin which is entered using the keyboard. The "c" in cin refers to "character" and "in" means "input". Hence cin means "character input". The cin object is used along with the extraction operator >> in order to receive a stream of characters.
In computer programming, we use the if statement to run a block code only when a certain condition is met. An if statement can be followed by an optional else statement, which executes when the boolean expression is false. There are three forms of if...else statements in C++: • if statement, • if...else statement, • if...else if...else statement, The if statement evaluates the condition inside the parentheses ( ). If the condition evaluates to true, the code inside the body of if is executed. If the condition evaluates to false, the code inside the body of if is skipped.
In C++ programming we are using the iostream standard library, it provides cin and cout methods for reading from input and writing to output respectively. To read and write from a file we are using the standard C++ library called fstream. Let us see the data types define in fstream library is: • ofstream: This data type represents the output file stream and is used to create files and to write information to files. • ifstream: This data type represents the input file stream and is used to read information from files. • fstream: This data type represents the file stream generally, and has the capabilities of both ofstream and ifstream which means it can create files, write information to files, and read information from files.
The getch() is a predefined non-standard function that is defined in conio.h header file. It is mostly used by the Dev C/C++, MS- DOS's compilers like Turbo C to hold the screen until the user passes a single value to exit from the console screen. It can also be used to read a single byte character or string from the keyboard and then print. It does not hold any parameters. It has no buffer area to store the input character in a program. The getch() function does not accept any parameter from the user. It returns the ASCII value of the key pressed by the user as an input.
Close file. Closes the file associated with the stream and disassociates it. Closes the given file stream. Any unwritten buffered data are flushed to the OS. Any unread buffered data are discarded. Whether or not the operation succeeds, the stream is no longer associated with a file, and the buffer allocated by std::setbuf or std::setvbuf, if any, is also disassociated and deallocated if automatic allocation was used. All internal buffers associated with the stream are disassociated from it and flushed: the content of any unwritten output buffer is written and the content of any unread input buffer is discarded.
Get string from stdin. Reads characters from the standard input (stdin) and stores them as a C string into str until a newline character or the end-of-file is reached. The newline character, if found, is not copied into str. A terminating null character is automatically appended after the characters copied to str. Notice that gets is quite different from fgets: not only gets uses stdin as source, but it does not include the ending newline character in the resulting string and does not allow to specify a maximum size for str (which can lead to buffer overflows). On success, the function returns str.
In C++, classes and structs are blueprints that are used to create the instance of a class. Structs are used for lightweight objects such as Rectangle, color, Point, etc. Unlike class, structs in C++ are value type than reference type. It is useful if you have data that is not intended to be modified after creation of struct. C++ Structure is a collection of different data types. It is similar to the class that holds different types of data. A structure is declared by preceding the struct keyword followed by the identifier(structure name). Inside the curly braces, we can declare the member variables of different types.
The cout is a predefined object of ostream class. It is connected with the standard output device, which is usually a display screen. The cout is used in conjunction with stream insertion operator (<<) to display the output on a console. On most program environments, the standard output by default is the screen, and the C++ stream object defined to access it is cout. The "c" in cout refers to "character" and "out" means "output". Hence cout means "character output". The cout object is used along with the insertion operator << in order to display a stream of characters.
Positions cursor in text window. The gotoxy() function places the cursor at the desired location on the screen. This means it is possible to change the cursor location on the screen using the gotoxy() function. It is basically used to print text wherever the cursor is moved. If the coordinates are in any way invalid the call to gotoxy is ignored. Neither argument to gotoxy can be zero.
In while loop, condition is evaluated first and if it returns true then the statements inside while loop execute, this happens repeatedly until the condition returns false. When condition returns false, the control comes out of loop and jumps to the next statement in the program after while loop. The important point to note when using while loop is that we need to use increment or decrement statement inside while loop so that the loop variable gets changed on each iteration, and at some point condition returns false. This way we can end the execution of while loop otherwise the loop would execute indefinitely. A while loop that never stops is said to be the infinite while loop, when we give the condition in such a way so that it never returns false, then the loops becomes infinite and repeats itself indefinitely.
A program shall contain a global function named main, which is the designated start of the program in hosted environment. main() function is the entry point of any C++ program. It is the point at which execution of program is started. When a C++ program is executed, the execution control goes directly to the main() function. Every C++ program have a main() function.
The exit function terminates the program normally. Automatic objects are not destroyed, but static objects are. Then, all functions registered with atexit are called in the opposite order of registration. The code is returned to the operating system. An exit code of 0 or EXIT_SUCCESS means successful completion. If code is EXIT_FAILURE, an indication of program failure is returned to the operating system. Other values of code are implementation-defined. Calls all functions registered with the atexit() function, and destroys C++ objects with static storage duration, all in last-in-first-out (LIFO) order. C++ objects with static storage duration are destroyed in the reverse order of the completion of their constructor. (Automatic objects are not destroyed as a result of calling exit().)
Algorithm finds the median of 2 sorted arrays using binary search approach. Takes the input of 'n' Data Elements of both the arrays. Using decrease, conquer method find the combined
User enters a number which stores in variable "num". Then number "passes as argument" in function call A static variable is used to check that how many times function is called. When
