The fprintf() is used to output the values of the arguments that make up the argument list as specified in the format string to the stream pointed to by stream.
#include<stdio.h> int fprintf(FILE *stream, const char *format, ...);
The return value is the number of characters actually printed. If an error occurs then a negative number is returned.
Following c program creates a file named demo.txt and writes this is a demo file 20 10.20 into the file using fprintf() function to format the data:
#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
void main()
{
clrscr();
FILE *fp;
fp=fopen("demo.txt", "wb");
if(fp==NULL)
{
printf("Error in opening the file..!!\n");
printf("Press any key to exit..\n");
getch();
exit(1);
}
fprintf(fp, "this is a demo file %d %f", 20, 10.20);
fclose(fp);
getch();
}