提示stdprn没定义,加了头文件stdlib.h解决思路

提示stdprn没定义,加了头文件stdlib.h
请问这是怎么回事,用的是VC编译器,Dev-C++也提示没定义


#include <stdio.h>
#include <stdlib.h>
void do_heading(char *filename);

int line =0,page =0;

int main(int argv,char *argc[])
{
char buffer[256];
FILE *fp;

if(argv < 2)
{
fprintf(stderr,"\nProper Usage is:");
fprintf(stderr,"\n\nprint_it filename.ext\n");
return(1);
}
if( (fp=fopen(argc[1],"r")) ==NULL)
{
fprintf(stderr,"Error opening file,%s!",argc[1]);
return(1);
}

page =0;
line =1;
do_heading(argc[1]);

while( fgets(buffer,256,fp) !=NULL)
{
if( line % 55 ==0)
do_heading(argc[1]);

fprintf( stdprn,"%4d:\t%s", line++, buffer);//提示stdprn没定义
}
}

------解决方案--------------------
stdprn,什么东西，
难道是stdout?