Code:
#include <stdio.h>
#include<stdlib.h>
main()
{
fprintf(stdprn ,"Hello\n");
}
It says stdprn is undeclared.
I googled it and this showed up
Quote:
stdprn defaults to using lpt1 (a parallel port). You will need to reopen stdprn (with the open() function) to associate it with your USB printer.
and the person who asked the question asked how to do that and the person replied Quote:
stdprn = open(your_usb_port_ID, O_WRONLY);
Then the person who asked the question posted this code:
Code:
#include <stdlib.h>
#include <stdio.h>
void do_heading(char *filename);
stdprn = open(USB001, O_WRONLY);
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 );
}
fprintf( stdprn, "\f" );
fclose(fp);
return 0;
}
void do_heading( char *filename )
{
page++;
if ( page > 1)
fprintf( stdprn, "\f" );
fprintf( stdprn, "Page: %d, %s\n\n", page, filename );
}
Which throws half a dozen of errors and warnings. here's the thread if you want to check it out: http://forums.devshed.com/programming-42/stdprn-help-318453.html
So, how do I write a program that makes my printer print something?