freebsd-dev/games/random/random.c
Ulrich Spörlein a118325368 random(6): avoid dead assignments
Found by:	clang static analyzer
2010-06-14 13:03:25 +00:00

195 lines
5.0 KiB
C

/*
* 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. 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.
*/
#if 0
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1994\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static const char sccsid[] = "@(#)random.c 8.5 (Berkeley) 4/5/94";
#endif /* not lint */
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "randomize_fd.h"
static void usage(void);
int
main(int argc, char *argv[])
{
double denom;
int ch, fd, random_exit, randomize_lines, random_type, ret,
selected, unique_output, unbuffer_output;
char *ep;
const char *filename;
denom = 0;
filename = "/dev/fd/0";
random_type = RANDOM_TYPE_UNSET;
random_exit = randomize_lines = unbuffer_output = 0;
unique_output = 1;
(void)setlocale(LC_CTYPE, "");
while ((ch = getopt(argc, argv, "ef:hlruUw")) != -1)
switch (ch) {
case 'e':
random_exit = 1;
break;
case 'f':
randomize_lines = 1;
if (strcmp(optarg, "-") != 0)
filename = optarg;
break;
case 'l':
randomize_lines = 1;
random_type = RANDOM_TYPE_LINES;
break;
case 'r':
unbuffer_output = 1;
break;
case 'u':
randomize_lines = 1;
unique_output = 1;
break;
case 'U':
randomize_lines = 1;
unique_output = 0;
break;
case 'w':
randomize_lines = 1;
random_type = RANDOM_TYPE_WORDS;
break;
default:
case '?':
usage();
/* NOTREACHED */
}
argc -= optind;
argv += optind;
switch (argc) {
case 0:
denom = (randomize_lines ? 1 : 2);
break;
case 1:
errno = 0;
denom = strtod(*argv, &ep);
if (errno == ERANGE)
err(1, "%s", *argv);
if (denom <= 0 || *ep != '\0')
errx(1, "denominator is not valid.");
if (random_exit && denom > 256)
errx(1, "denominator must be <= 256 for random exit.");
break;
default:
usage();
/* NOTREACHED */
}
srandomdev();
/*
* Act as a filter, randomly choosing lines of the standard input
* to write to the standard output.
*/
if (unbuffer_output)
setbuf(stdout, NULL);
/*
* Act as a filter, randomizing lines read in from a given file
* descriptor and write the output to standard output.
*/
if (randomize_lines) {
if ((fd = open(filename, O_RDONLY, 0)) < 0)
err(1, "%s", filename);
ret = randomize_fd(fd, random_type, unique_output, denom);
if (!random_exit)
return(ret);
}
/* Compute a random exit status between 0 and denom - 1. */
if (random_exit)
return (int)(denom * random() / RANDOM_MAX_PLUS1);
/*
* 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() / RANDOM_MAX_PLUS1) == 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() /
RANDOM_MAX_PLUS1) == 0;
}
}
if (ferror(stdin))
err(2, "stdin");
exit (0);
}
static void
usage(void)
{
fprintf(stderr, "usage: random [-elrUuw] [-f filename] [denominator]\n");
exit(1);
}