1/*	$OpenBSD: dc.c,v 1.11 2009/10/27 23:59:37 deraadt Exp $	*/
2
3/*
4 * Copyright (c) 2003, Otto Moerbeek <otto@drijf.net>
5 * Copyright (c) 2009, Gabor Kovesdan <gabor@FreeBSD.org>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20#include <sys/cdefs.h>
21__FBSDID("$FreeBSD: stable/11/usr.bin/dc/dc.c 332463 2018-04-13 03:30:10Z kevans $");
22
23#include <sys/stat.h>
24
25#include <capsicum_helpers.h>
26#include <ctype.h>
27#include <err.h>
28#include <errno.h>
29#include <fcntl.h>
30#include <getopt.h>
31#include <stdio.h>
32#include <stdlib.h>
33#include <string.h>
34#include <unistd.h>
35
36#include "extern.h"
37
38#define	DC_VER		"1.3-FreeBSD"
39
40static void		 usage(void);
41
42extern char		*__progname;
43
44static struct source	 src;
45
46static const struct option long_options[] =
47{
48	{"expression",		required_argument,	NULL,	'e'},
49	{"file",		required_argument,	NULL,	'f'},
50	{"help",		no_argument,		NULL,	'h'},
51	{"version",		no_argument,		NULL,	'V'}
52};
53
54static void
55usage(void)
56{
57	fprintf(stderr, "usage: %s [-hVx] [-e expression] [file]\n",
58	    __progname);
59	exit(1);
60}
61
62static void
63procfd(int fd, char *fname) {
64	struct stat st;
65	FILE *file;
66
67	file = fdopen(fd, "r");
68	if (file == NULL)
69		err(1, "cannot open file %s", fname);
70	if (fstat(fileno(file), &st) == -1)
71		err(1, "%s", fname);
72	if (S_ISDIR(st.st_mode)) {
73		errno = EISDIR;
74		err(1, "%s", fname);
75	}
76	src_setstream(&src, file);
77	reset_bmachine(&src);
78	eval();
79	fclose(file);
80}
81
82int
83main(int argc, char *argv[])
84{
85	int ch, fd;
86	bool extended_regs = false, preproc_done = false;
87
88	/* accept and ignore a single dash to be 4.4BSD dc(1) compatible */
89	while ((ch = getopt_long(argc, argv, "e:f:hVx", long_options, NULL)) != -1) {
90		switch (ch) {
91		case 'e':
92			if (!preproc_done)
93				init_bmachine(extended_regs);
94			src_setstring(&src, optarg);
95			reset_bmachine(&src);
96			eval();
97			preproc_done = true;
98			break;
99		case 'f':
100			if (!preproc_done)
101				init_bmachine(extended_regs);
102			fd = open(optarg, O_RDONLY);
103			if (fd < 0)
104				err(1, "cannot open file %s", optarg);
105			procfd(fd, optarg);
106			preproc_done = true;
107			break;
108		case 'x':
109			extended_regs = true;
110			break;
111		case 'V':
112			fprintf(stderr, "%s (BSD bc) %s\n", __progname, DC_VER);
113			exit(0);
114			break;
115		case '-':
116			break;
117		case 'h':
118			/* FALLTHROUGH */
119		default:
120			usage();
121		}
122	}
123	argc -= optind;
124	argv += optind;
125
126	if (!preproc_done)
127		init_bmachine(extended_regs);
128	(void)setvbuf(stdout, NULL, _IOLBF, 0);
129	(void)setvbuf(stderr, NULL, _IOLBF, 0);
130
131	if (argc > 1)
132		usage();
133	if (argc == 1) {
134		fd = open(argv[0], O_RDONLY);
135		if (fd < 0)
136			err(1, "cannot open file %s", argv[0]);
137
138		if (caph_limit_stream(fd, CAPH_READ) < 0 ||
139		    caph_limit_stdio() < 0 ||
140		    (cap_enter() < 0 && errno != ENOSYS))
141			err(1, "capsicum");
142
143		procfd(fd, argv[0]);
144		preproc_done = true;
145	}
146	if (preproc_done)
147		return (0);
148
149	if (caph_limit_stdio() < 0 || (cap_enter() < 0 && errno != ENOSYS))
150		err(1, "capsicum");
151	src_setstream(&src, stdin);
152	reset_bmachine(&src);
153	eval();
154
155	return (0);
156}
157