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fflush() function in C:

fflush() function is a file handling function in C programming language which is used to flush/clean the file or buffer. Please find below the description and syntax for above file handling function.

File operation

Declaration & Description

fflush()

Declaration: int fflush(FILE *fp)

fflush() function is used to flush/clean the file or buffer. In a C program, we can use fflush() function as below.
fflush(buffer);

where, buffer is a temporary variable or pointer which loads/points the data.

Example program for fflush() function in C programming language:

fflush() function is used to flush a file or buffer. i.e. it cleans it (making empty) if it has been loaded with any other data already.

#include <stdio.h>
int main()
{
   char buf[50];
   FILE *fp;
   fp = fopen("test.txt", "r+");
   if (fp)
   {
      fputs("Test data by Fresh2refres", fp);
      fflush(buf); // flushes the buffer to load the data from file
      fgets(buf, 20, fp); // It loads 1st 20 characters from file to buffer
      puts(buf); // It displays buffer data in output screen
      fclose(fp);
      return 0;
   }
   return 1;
}

#include <stdio.h>

int main()

{

char buf[50];

FILE *fp;

fp = fopen("test.txt", "r+");

if (fp)

{

fputs("Test data by Fresh2refres", fp);

fflush(buf); // flushes the buffer to load the data from file

fgets(buf, 20, fp); // It loads 1st 20 characters from file to buffer

puts(buf); // It displays buffer data in output screen

fclose(fp);

return 0;

}

return 1;

}

Output:

Test data by Fresh2refresh

Other Inbuilt file handling functions in C programming language:

C programming language offers many other inbuilt functions for handling files. They are given below. Please click on each function name below to know more details, example programs, output for the respective file handling function.

File handling functions	Description
fopen ()	fopen () function creates a new file or opens an existing file.
fclose ()	fclose () function closes an opened file.
getw ()	getw () function reads an integer from file.
putw ()	putw () functions writes an integer to file.
fgetc ()	fgetc () function reads a character from file.
fputc ()	fputc () functions write a character to file.
gets ()	gets () function reads line from keyboard.
puts ()	puts () function writes line to o/p screen.
fgets ()	fgets () function reads string from a file, one line at a time.
fputs ()	fputs () function writes string to a file.
feof ()	feof () function finds end of file.
fgetchar ()	fgetchar () function reads a character from keyboard.
fprintf ()	fprintf () function writes formatted data to a file.
fscanf ()	fscanf () function reads formatted data from a file.
fputchar ()	fputchar () function writes a character onto the output screen from keyboard input.
fseek ()	fseek () function moves file pointer position to given location.
SEEK_SET	SEEK_SET moves file pointer position to the beginning of the file.
SEEK_CUR	SEEK_CUR moves file pointer position to given location.
SEEK_END	SEEK_END moves file pointer position to the end of file.
ftell ()	ftell () function gives current position of file pointer.
rewind ()	rewind () function moves file pointer position to the beginning of the file.
getc ()	getc () function reads character from file.
getch ()	getch () function reads character from keyboard.
getche ()	getche () function reads character from keyboard and echoes to o/p screen.
getchar ()	getchar () function reads character from keyboard.
putc ()	putc () function writes a character to file.
putchar ()	putchar () function writes a character to screen.
printf ()	printf () function writes formatted data to screen.
sprinf ()	sprinf () function writes formatted output to string.
scanf ()	scanf () function reads formatted data from keyboard.
sscanf ()	sscanf () function Reads formatted input from a string.
remove ()	remove () function deletes a file.
fflush ()	fflush () function flushes a file.

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