// crt_fprintf.c
/* This program uses fprintf to format various
* data and print it to the file named FPRINTF.OUT. It
* then displays FPRINTF.OUT on the screen using the system
* function to invoke the operating-system TYPE command.
*/
#include <stdio.h>
#include <process.h>
FILE *stream;
int main( void )
{
int i = 10;
double fp = 1.5;
char s[] = "this is a string";
char c = '\n';
fopen_s( &stream, "fprintf.out", "w" );
fprintf( stream, "%s%c", s, c );//第一个表示输出流，stderr是一个标准错误输出流，第二个参数表示输出格式，第三个参数s，c等表示要输出的变量。
fprintf( stream, "%d\n", i );
fprintf( stream, "%f\n", fp );
fclose( stream );
system( "type fprintf.out" );
}