Files In C Language

 

Files In C Language

File : File is a collection of data or information which is used to store the data permanently
Types of files:
1.Text Files
2.Document Files
3.Audio Files
4.Video Files
5.PDF Files ...


File Operations
1.Open or create a file
2.Write the data into the file
3.Read the data from the file
4.close a file
Open file

FILE *fopen( const char * filename, const char * mode );

Here, filename is a string literal, which you will use to name your file, and access mode can have one of the following values −

Sno	Mode	Description
1	r	Opens an existing text file for reading purpose.
2	w	Opens a text file for writing. If it does not exist, then a new file is created. Here your program will start writing content from the beginning of the file.
3	a	Opens a text file for writing in appending mode. If it does not exist, then a new file is created. Here your program will start appending content in the existing file content.
4	r+	Opens a text file for both reading and writing.
5	w+	Opens a text file for both reading and writing. It first truncates the file to zero length if it exists, otherwise creates a file if it does not exist.
6	a+	Opens a text file for both reading and writing. It creates the file if it does not exist. The reading will start from the beginning but writing can only be appended.

If you are going to handle binary files, then you will use following access modes instead of the above mentioned ones −

  "rb", "wb", "ab", "rb+", "r+b", "wb+", "w+b", "ab+", "a+b"

Closing File:

int fclose( FILE *fp );
Close a file using fclose( ) function

Writing a File:

fprintf(file,"Data")

fputs("Data",File)

Program:

#include <stdio.h>
#include <conio.h>
void main() {
   FILE *fp;
   fp = fopen("test.txt", "w+");
   fprintf(fp, "This is testing File\n");
   fputs("This is testing File\n", fp);
   fclose(fp);
   printf("Success");
   getch();
}

Reading a File

fscanf(File,"type of data",variable);

fgets(variable,size, FILE)

Program

#include <stdio.h>
#include <conio.h>

void main() {

   FILE *fp;
   char x[255];

   fp = fopen("test.txt", "r");
   fscanf(fp, "%s", x);
   printf("1 : %s\n", x );

   fgets(x, 255, (FILE*)fp);
   printf("2: %s\n", x );
   
   fclose(fp);
   printf("Success");
   getch();

}