File in C Programming Language

File in C Programming Language

In this tutorial, We will learn about file management in the C programming language.

Introduction

File management in C, File operation functions in C, Defining and opening a file, Closing a file, reading a file and writing to a file.

File Operation function in C

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fopen()	Creates a new file for use Opens a new existing file for use
fclose()	Closes a file which has been opened for use
getc()	Reads a character from a file
putc()	Writes a character to a file
fprintf()	Writes a set of data values to a file
fscanf()	Reads a set of data values from a file
getw()	Reads a integer from a file
putw()	Writes an integer to the file
fseek()	Sets the position to a desired point in the file
ftell()	Gives the current position in the file
rewind()	Sets the position to the begining of the file

Read File in C

 /*  
  * C program to illustrate how a file stored on the disk is read  
  */  
 #include <stdio.h>  
 #include <stdlib.h>  
 void main()  
 {  
   FILE *fptr;  
   char filename[15];  
   char ch;  
   printf("Enter the filename to be opened \n");  
   scanf("%s", filename);  
   /* open the file for reading */  
   fptr = fopen(filename, "r");  
   if (fptr == NULL)  
   {  
     printf("Cannot open file \n");  
     exit(0);  
   }  
   ch = fgetc(fptr);  
   while (ch != EOF)  
   {  
     printf ("%c", ch);  
     ch = fgetc(fptr);  
   }  
   fclose(fptr);  
 }  

Write to File in C

 #include <stdio.h>  
 int main()  
 {  
   int num;  
   FILE *fptr;  
   fptr = fopen("program.txt","w");  
   if(fptr == NULL)  
   {  
    printf("Error!");    
    exit(1);         
   }  
   printf("Enter num: ");  
   scanf("%d",&num);  
   fprintf(fptr,"%d",num);  
   fclose(fptr);  
   return 0;  
 }  

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