1*de973ec2Srillig /* $NetBSD: h_hexdump_r.c,v 1.1 2024/04/28 14:39:22 rillig Exp $ */
2*de973ec2Srillig
3*de973ec2Srillig /*
4*de973ec2Srillig * Copyright (c) 2024 The NetBSD Foundation, Inc.
5*de973ec2Srillig * All rights reserved.
6*de973ec2Srillig *
7*de973ec2Srillig * This code was contributed to The NetBSD Foundation by Roland Illig.
8*de973ec2Srillig *
9*de973ec2Srillig * Redistribution and use in source and binary forms, with or without
10*de973ec2Srillig * modification, are permitted provided that the following conditions
11*de973ec2Srillig * are met:
12*de973ec2Srillig * 1. Redistributions of source code must retain the above copyright
13*de973ec2Srillig * notice, this list of conditions and the following disclaimer.
14*de973ec2Srillig * 2. Redistributions in binary form must reproduce the above copyright
15*de973ec2Srillig * notice, this list of conditions and the following disclaimer in the
16*de973ec2Srillig * documentation and/or other materials provided with the distribution.
17*de973ec2Srillig *
18*de973ec2Srillig * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19*de973ec2Srillig * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20*de973ec2Srillig * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21*de973ec2Srillig * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22*de973ec2Srillig * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23*de973ec2Srillig * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24*de973ec2Srillig * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25*de973ec2Srillig * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26*de973ec2Srillig * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27*de973ec2Srillig * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28*de973ec2Srillig * POSSIBILITY OF SUCH DAMAGE.
29*de973ec2Srillig */
30*de973ec2Srillig
31*de973ec2Srillig /* Given the output from "hexdump -C", reconstruct the original file. */
32*de973ec2Srillig
33*de973ec2Srillig #include <err.h>
34*de973ec2Srillig #include <inttypes.h>
35*de973ec2Srillig #include <regex.h>
36*de973ec2Srillig #include <stdio.h>
37*de973ec2Srillig #include <stdlib.h>
38*de973ec2Srillig #include <string.h>
39*de973ec2Srillig
40*de973ec2Srillig #define H "[0-9a-f]"
41*de973ec2Srillig #define HH " (" H H ")"
42*de973ec2Srillig
43*de973ec2Srillig static off_t off, noff;
44*de973ec2Srillig static unsigned char prev_bytes[16], bytes[16], zeroes[16];
45*de973ec2Srillig
46*de973ec2Srillig int
main(void)47*de973ec2Srillig main(void)
48*de973ec2Srillig {
49*de973ec2Srillig char line[81];
50*de973ec2Srillig regex_t data_re, end_re;
51*de973ec2Srillig regmatch_t m[18];
52*de973ec2Srillig
53*de973ec2Srillig if (regcomp(&data_re, "^(" H "{8,9})"
54*de973ec2Srillig " " HH HH HH HH HH HH HH HH " " HH HH HH HH HH HH HH HH
55*de973ec2Srillig " \\|.{16}\\|$", REG_EXTENDED) != 0)
56*de973ec2Srillig err(1, "regcomp");
57*de973ec2Srillig if (regcomp(&end_re, "^(" H "{8,9})$", REG_EXTENDED) != 0)
58*de973ec2Srillig err(1, "regcomp");
59*de973ec2Srillig
60*de973ec2Srillig while (fgets(line, sizeof(line), stdin) != NULL) {
61*de973ec2Srillig line[strcspn(line, "\n")] = '\0';
62*de973ec2Srillig
63*de973ec2Srillig if (strcmp(line, "*") == 0)
64*de973ec2Srillig continue;
65*de973ec2Srillig
66*de973ec2Srillig if (regexec(&data_re, line, 18, m, 0) == 0) {
67*de973ec2Srillig noff = (off_t)strtoimax(line + m[1].rm_so, NULL, 16);
68*de973ec2Srillig for (size_t i = 0; i < 16; i++)
69*de973ec2Srillig bytes[i] = (unsigned char)strtoumax(
70*de973ec2Srillig line + m[2 + i].rm_so, NULL, 16);
71*de973ec2Srillig
72*de973ec2Srillig } else if (regexec(&end_re, line, 2, m, 0) == 0) {
73*de973ec2Srillig noff = (off_t)strtoimax(line + m[1].rm_so, NULL, 16);
74*de973ec2Srillig if (off < noff) {
75*de973ec2Srillig if (fseeko(stdout, noff - 16, SEEK_SET) != 0)
76*de973ec2Srillig err(1, "fseeko");
77*de973ec2Srillig if (fwrite(prev_bytes, 1, 16, stdout) != 16)
78*de973ec2Srillig err(1, "fwrite");
79*de973ec2Srillig }
80*de973ec2Srillig } else
81*de973ec2Srillig err(1, "invalid line '%s'", line);
82*de973ec2Srillig
83*de973ec2Srillig if (memcmp(prev_bytes, zeroes, 16) != 0) {
84*de973ec2Srillig while (off < noff) {
85*de973ec2Srillig if (fwrite(prev_bytes, 1, 16, stdout) != 16)
86*de973ec2Srillig err(1, "fwrite");
87*de973ec2Srillig off += 16;
88*de973ec2Srillig }
89*de973ec2Srillig if (off != noff)
90*de973ec2Srillig err(1, "off");
91*de973ec2Srillig } else {
92*de973ec2Srillig if (fseeko(stdout, noff, SEEK_SET) != 0)
93*de973ec2Srillig err(1, "fseeko");
94*de973ec2Srillig off = noff;
95*de973ec2Srillig }
96*de973ec2Srillig
97*de973ec2Srillig memcpy(prev_bytes, bytes, 16);
98*de973ec2Srillig }
99*de973ec2Srillig return 0;
100*de973ec2Srillig }
101