Read data from file

fscanf() function is used to read data from file.

Syntax of fscanf() :

fscanf(file_pointer, format_specifier, variable);

Code example:

#include<stdio.h>
int main()
{
     FILE fp;
     fp=fopen("C://test.txt","w"); // open file in writing mode
     fprintf(fp,"KUET EEE");
     fclose(fp);
     fp=fopen("C://test.txt","r"); // open file in reading mode
     char s[20];
     fscanf(fp,"%s",s);
     printf("%s",s);
     return 0;
}

Here first we open test.txt in writing mode and write “KUET EEE” text. Then retrieve first word “KUET” by

fscanf(fp,"%s",s);

Here s[20] can contain 19 character but why only “KUET” is retrieved by

fscanf(fp,"%s",s);

Here retrieving data has been terminated by space. Notice there is space between “KUET” and “EEE”.

So, How to read all data including space? is a big question.
We can do this by feof() function.

#include<stdio.h>
int main()
{
     FILE *fp;
     fp=fopen("C://test.txt","r");
     while(feof(fp) ==0)
     {
         fscanf(fp,"%s",s);
         printf("%s\n",s);
     }
     return 0;
}

feof() function will return non-zero value for any position of file except end of the file and zero value for the end position of file. File position is updated by file pointer fp.

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