slow show command with loops (but without bugs)

Here is a working version of my slow show command with loops.
No it works on SUNS and PCS 


/* slow show command by Christoph Hager */
#include <stdio.h>
#include <string.h>
#define DELAY 1  /* test how fast your system is */
void do_sleep(delay)
int delay;
{
long int t;
	for (t=0;t<delay*1000;t++) ;
}
main(argc, argv)   
int argc;
char *argv[];
{
FILE *in;
long pos;  
char ch,*line,linea[90];
int i,t,delay;

	if (argc < 2 || (argc==3 && !atoi(argv[2])) || (argc==4 && !atoi(argv[2]) && !atoi(argv[3])) || argc > 4) {
		printf ("Usage: %s <name of file> <number of loops>\n",argv[0]);
		exit(1);
	}
	if (argc==3) { t=atoi(argv[2]); delay=DELAY; }
	else if (argc==4) { t=atoi(argv[2]); delay=atoi(argv[3]); }
	else { t=1; delay=DELAY; }
	if ((in = fopen(argv[1], "r")) == NULL) {
		fprintf (stderr, "Error: Can't read %s\n", argv[1]);
		exit(1);
	}
	pos=ftell(in);     
	for (i=0;i<t;i++) {
		while (!feof(in)) {
			putc(getc(in),stdout);
			do_sleep(DELAY);
		}
		fseek(in,pos,0);
	}
}