minix/commands/fortune/fortune.c

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2005-04-21 16:53:53 +02:00
/* fortune - hand out Chinese fortune cookies Author: Bert Reuling */
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#define COOKIEJAR "/usr/lib/fortune.dat"
static char *Copyright = "\0Copyright (c) 1990 Bert Reuling";
static unsigned long seed;
_PROTOTYPE(int main, (int argc, char **argv));
_PROTOTYPE(unsigned long magic, (unsigned long range));
int main(argc, argv)
int argc;
char *argv[];
{
int c1, c2, c3;
struct stat cookie_stat;
FILE *cookie;
if ((cookie = fopen(COOKIEJAR, "r")) == NULL) {
printf("\nSome things better stay closed.\n - %s\n", argv[0]);
exit (-1);
}
/* Create seed from : date, time, user-id and process-id. we can't get
* the position of the moon, unfortunately.
*/
seed = time( (time_t *) 0) ^ (long) getuid() ^ (long) getpid();
if (stat(COOKIEJAR, &cookie_stat) != 0) {
printf("\nIt furthers one to see the super guru.\n - %s\n", argv[0]);
exit (-1);
}
fseek(cookie, magic((unsigned long) cookie_stat.st_size), 0); /* m ove bu magic... */
c2 = c3 = '\n';
while (((c1 = getc(cookie)) != EOF) && ((c1 != '%') || (c2 != '%') || (c3 != '\n'))) {
c3 = c2;
c2 = c1;
}
if (c1 == EOF) {
printf("\nSomething unexpected has happened.\n - %s", argv[0]);
exit (-1);
}
c2 = c3 = '\n';
while (((c1 = getc(cookie)) != '%') || (c2 != '%') || (c3 != '\n')) {
if (c1 == EOF) {
rewind(cookie);
continue;
}
putc(c2, stdout);
c3 = c2;
c2 = c1;
}
putc('\n', stdout);
fclose(cookie);
return (0);
}
/* magic - please study carefull: there is more than meets the eye */
unsigned long magic(range)
unsigned long range;
{
seed = 9065531L * (seed % 9065533L) - 2 * (seed / 9065531L) + 1L;
return (seed % range);
}