Example Program for FSEEK() function in c programming

 fseek() function in c programming is used to write data into desired file with the help of pointer which help to find the location into the given file.

Example Program for FSEEK() function in c programming

 

Syntax :-

int fseek(FILE *stream, long int offset, int whence)  

There are three constants are used in fseeks() function in c  SEEK_SET, SEEK_CUR and SEEK_END

 #include <stdio.h>
void main(){  
   FILE *fp;  
  
   fp = fopen("myfile.txt","w+");  
   fputs("This is functioinc", fp);  
    
   fseek( fp, 7, SEEK_SET );  
   fputs("Adam stiffman", fp);  
   fclose(fp);  
} 

Now let see the Example Program for FSEEK() function in c

#include <stdio.h>
int main ()
{
   FILE *f;
   char data[60];
   fp = fopen ("test.c","w");
   fputs("functioinc.in is a programming tutorial website", f);
   fgets ( data, 60, fp );
   printf(Before fseek - %s", data); 
 
   // To set file pointet to 21th byte/character into the file
   fseek(f, 21, SEEK_SET);
   fflush(data);
   fgets ( data, 60, fp );
   printf("After SEEK_SET to 21 - %s", data);
 
   // To find backward 10 bytes 
   fseek(f, -10, SEEK_CUR);
   fflush(data);
   fgets ( data, 60, fp );
   printf("After SEEK_CUR to -10 - %s", data);
 
   // To find 7th byte before the end of file
   fseek(f, -7, SEEK_END); 
   fflush(data);
   fgets ( data, 60, f );
   printf("After SEEK_END to -7 - %s", data);
 
   // now set file pointer to the start of the file
   fseek(f, 0, SEEK_SET); 
 
   fclose(f);
   return 0;
}