aboutsummaryrefslogtreecommitdiff
path: root/dd.c
blob: e445e043596a83c82debcf88028151b07c24ef42 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
/* vi: set sw=4 ts=4: */
/*
 * Mini dd implementation for busybox
 *
 *
 * Copyright (C) 2000 by Matt Kraai <kraai@alumni.carnegiemellon.edu>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include "busybox.h"

#include <sys/types.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>

static const struct suffix_mult dd_suffixes[] = {
	{ "c", 1 },
	{ "w", 2 },
	{ "b", 512 },
	{ "kD", 1000 },
	{ "k", 1024 },
	{ "MD", 1000000 },
	{ "M", 1048576 },
	{ "GD", 1000000000 },
	{ "G", 1073741824 },
	{ NULL, 0 }
};

int dd_main(int argc, char **argv)
{
	int i, ifd, ofd, oflag, sync = FALSE, trunc = TRUE;
	size_t in_full = 0, in_part = 0, out_full = 0, out_part = 0;
	size_t bs = 512, count = -1;
	ssize_t n;
	off_t seek = 0, skip = 0;
	FILE *statusfp;
	char *infile = NULL, *outfile = NULL, *buf;

	for (i = 1; i < argc; i++) {
		if (strncmp("bs=", argv[i], 3) == 0)
			bs = parse_number(argv[i]+3, dd_suffixes);
		else if (strncmp("count=", argv[i], 6) == 0)
			count = parse_number(argv[i]+6, dd_suffixes);
		else if (strncmp("seek=", argv[i], 5) == 0)
			seek = parse_number(argv[i]+5, dd_suffixes);
		else if (strncmp("skip=", argv[i], 5) == 0)
			skip = parse_number(argv[i]+5, dd_suffixes);
		else if (strncmp("if=", argv[i], 3) == 0)
			infile = argv[i]+3;
		else if (strncmp("of=", argv[i], 3) == 0)
			outfile = argv[i]+3;
		else if (strncmp("conv=", argv[i], 5) == 0) {
			buf = argv[i]+5;
			while (1) {
				if (strncmp("notrunc", buf, 7) == 0) {
					trunc = FALSE;
					buf += 7;
				} else if (strncmp("sync", buf, 4) == 0) {
					sync = TRUE;
					buf += 4;
				} else {
					error_msg_and_die("invalid conversion `%s'", argv[i]+5);
				}
				if (buf[0] == '\0')
					break;
				if (buf[0] == ',')
					buf++;
			}
		} else
			show_usage();
	}

	buf = xmalloc(bs);

	if (infile != NULL) {
		if ((ifd = open(infile, O_RDONLY)) < 0)
			perror_msg_and_die("%s", infile);
	} else {
		ifd = STDIN_FILENO;
		infile = "standard input";
	}

	if (outfile != NULL) {
		oflag = O_WRONLY | O_CREAT;

		if (!seek && trunc)
			oflag |= O_TRUNC;

		if ((ofd = open(outfile, oflag, 0666)) < 0)
			perror_msg_and_die("%s", outfile);

		if (seek && trunc) {
			if (ftruncate(ofd, seek * bs) < 0)
				perror_msg_and_die("%s", outfile);
		}

		statusfp = stdout;
	} else {
		ofd = STDOUT_FILENO;
		outfile = "standard output";
		statusfp = stderr;
	}

	if (skip) {
		if (lseek(ifd, skip * bs, SEEK_CUR) < 0)
			perror_msg_and_die("%s", infile);
	}

	if (seek) {
		if (lseek(ofd, seek * bs, SEEK_CUR) < 0)
			perror_msg_and_die("%s", outfile);
	}

	while (in_full + in_part != count) {
		n = safe_read(ifd, buf, bs);
		if (n < 0)
			perror_msg_and_die("%s", infile);
		if (n == 0)
			break;
		if (n == bs)
			in_full++;
		else
			in_part++;
		if (sync) {
			memset(buf + n, '\0', bs - n);
			n = bs;
		}
		n = full_write(ofd, buf, n);
		if (n < 0)
			perror_msg_and_die("%s", outfile);
		if (n == bs)
			out_full++;
		else
			out_part++;
	}

	fprintf(statusfp, "%d+%d records in\n", in_full, in_part);
	fprintf(statusfp, "%d+%d records out\n", out_full, out_part);

	return EXIT_SUCCESS;
}