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; }