The function int fflush(FILE *stream); causes the content of an output buffer to be written on a file. The stream remains open after a call to fflush function. If stream is a null pointer, then all such streams are flushed.
All buffers automatically gets flushed when program terminates or because of a call to fclose or when they become full.
Function prototype of fflush
int fflush(FILE *stream);
- stream : A pointer to a FILE object which identifies a stream.
Return value of fflush
This function returns zero value on success. If an error occurs, It returns EOF and the error indicator is set.
C program using fflush function
#include <stdio.h>
#include <string.h>
int main(){
char buffer[100];
memset(buffer, '\0', sizeof(buffer));
setvbuf(stdout, buffer, _IOFBF, 100);
fputs("fflush C Standard library function\n", stdout);
fflush(stdout);
return(0);
}
Output
fflush C Standard library function