1994-09-04 04:03:31 +00:00
|
|
|
/*
|
|
|
|
* Copyright (c) 1994
|
|
|
|
* The Regents of the University of California. All rights reserved.
|
|
|
|
*
|
|
|
|
* This code is derived from software contributed to Berkeley by
|
|
|
|
* Guy Harris at Network Appliance Corp.
|
|
|
|
*
|
|
|
|
* Redistribution and use in source and binary forms, with or without
|
|
|
|
* modification, are permitted provided that the following conditions
|
|
|
|
* are met:
|
|
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
|
|
* notice, this list of conditions and the following disclaimer.
|
|
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
|
|
* documentation and/or other materials provided with the distribution.
|
|
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
|
|
* must display the following acknowledgement:
|
|
|
|
* This product includes software developed by the University of
|
|
|
|
* California, Berkeley and its contributors.
|
|
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
|
|
* may be used to endorse or promote products derived from this software
|
|
|
|
* without specific prior written permission.
|
|
|
|
*
|
|
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
|
|
* SUCH DAMAGE.
|
|
|
|
*/
|
|
|
|
|
|
|
|
#ifndef lint
|
1999-11-30 03:50:02 +00:00
|
|
|
static const char copyright[] =
|
1994-09-04 04:03:31 +00:00
|
|
|
"@(#) Copyright (c) 1994\n\
|
|
|
|
The Regents of the University of California. All rights reserved.\n";
|
|
|
|
#endif /* not lint */
|
|
|
|
|
|
|
|
#ifndef lint
|
1999-11-30 03:50:02 +00:00
|
|
|
#if 0
|
1994-09-04 04:03:31 +00:00
|
|
|
static char sccsid[] = "@(#)random.c 8.5 (Berkeley) 4/5/94";
|
1999-11-30 03:50:02 +00:00
|
|
|
#endif
|
|
|
|
static const char rcsid[] =
|
|
|
|
"$FreeBSD$";
|
1994-09-04 04:03:31 +00:00
|
|
|
#endif /* not lint */
|
|
|
|
|
|
|
|
#include <sys/types.h>
|
|
|
|
|
|
|
|
#include <err.h>
|
|
|
|
#include <errno.h>
|
1995-02-03 20:55:37 +00:00
|
|
|
#include <limits.h>
|
1994-09-04 04:03:31 +00:00
|
|
|
#include <stdio.h>
|
|
|
|
#include <stdlib.h>
|
|
|
|
#include <time.h>
|
|
|
|
#include <unistd.h>
|
|
|
|
|
|
|
|
void usage __P((void));
|
|
|
|
|
|
|
|
int
|
|
|
|
main(argc, argv)
|
|
|
|
int argc;
|
|
|
|
char *argv[];
|
|
|
|
{
|
|
|
|
extern int optind;
|
|
|
|
double denom;
|
|
|
|
int ch, random_exit, selected, unbuffer_output;
|
|
|
|
char *ep;
|
|
|
|
|
|
|
|
random_exit = unbuffer_output = 0;
|
1998-03-01 05:10:28 +00:00
|
|
|
while ((ch = getopt(argc, argv, "er")) != -1)
|
1994-09-04 04:03:31 +00:00
|
|
|
switch (ch) {
|
|
|
|
case 'e':
|
|
|
|
random_exit = 1;
|
|
|
|
break;
|
|
|
|
case 'r':
|
|
|
|
unbuffer_output = 1;
|
|
|
|
break;
|
|
|
|
default:
|
|
|
|
case '?':
|
|
|
|
usage();
|
|
|
|
/* NOTREACHED */
|
|
|
|
}
|
|
|
|
|
|
|
|
argc -= optind;
|
|
|
|
argv += optind;
|
|
|
|
|
|
|
|
switch (argc) {
|
|
|
|
case 0:
|
|
|
|
denom = 2;
|
|
|
|
break;
|
|
|
|
case 1:
|
|
|
|
errno = 0;
|
|
|
|
denom = strtod(*argv, &ep);
|
|
|
|
if (errno == ERANGE)
|
|
|
|
err(1, "%s", *argv);
|
1997-03-30 23:33:29 +00:00
|
|
|
if (denom <= 0 || *ep != '\0')
|
1994-09-04 04:03:31 +00:00
|
|
|
errx(1, "denominator is not valid.");
|
1997-03-30 23:33:29 +00:00
|
|
|
if (random_exit && denom > 255)
|
|
|
|
errx(1, "denominator must be <= 255 for random exit.");
|
1994-09-04 04:03:31 +00:00
|
|
|
break;
|
|
|
|
default:
|
1995-05-30 03:37:36 +00:00
|
|
|
usage();
|
1994-09-04 04:03:31 +00:00
|
|
|
/* NOTREACHED */
|
|
|
|
}
|
|
|
|
|
1997-06-14 00:37:08 +00:00
|
|
|
srandomdev();
|
1994-09-04 04:03:31 +00:00
|
|
|
|
|
|
|
/* Compute a random exit status between 0 and denom - 1. */
|
|
|
|
if (random_exit)
|
|
|
|
return ((denom * random()) / LONG_MAX);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Act as a filter, randomly choosing lines of the standard input
|
|
|
|
* to write to the standard output.
|
|
|
|
*/
|
|
|
|
if (unbuffer_output)
|
|
|
|
setbuf(stdout, NULL);
|
1995-05-30 03:37:36 +00:00
|
|
|
|
1994-09-04 04:03:31 +00:00
|
|
|
/*
|
|
|
|
* Select whether to print the first line. (Prime the pump.)
|
|
|
|
* We find a random number between 0 and denom - 1 and, if it's
|
|
|
|
* 0 (which has a 1 / denom chance of being true), we select the
|
|
|
|
* line.
|
|
|
|
*/
|
|
|
|
selected = (int)(denom * random() / LONG_MAX) == 0;
|
|
|
|
while ((ch = getchar()) != EOF) {
|
|
|
|
if (selected)
|
|
|
|
(void)putchar(ch);
|
|
|
|
if (ch == '\n') {
|
|
|
|
/* End of that line. See if we got an error. */
|
|
|
|
if (ferror(stdout))
|
|
|
|
err(2, "stdout");
|
|
|
|
|
|
|
|
/* Now see if the next line is to be printed. */
|
|
|
|
selected = (int)(denom * random() / LONG_MAX) == 0;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
if (ferror(stdin))
|
|
|
|
err(2, "stdin");
|
|
|
|
exit (0);
|
|
|
|
}
|
|
|
|
|
|
|
|
void
|
|
|
|
usage()
|
|
|
|
{
|
|
|
|
|
|
|
|
(void)fprintf(stderr, "usage: random [-er] [denominator]\n");
|
|
|
|
exit(1);
|
|
|
|
}
|