summaryrefslogtreecommitdiff
path: root/dd.c
blob: 8f1b9d409801f2abdf6c278b71eeb419a2280b30 (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
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
/*
 * Copyright (c) 1999 by David I. Bell
 * Permission is granted to use, distribute, or modify this source,
 * provided that this copyright notice remains intact.
 *
 * The "dd" command, originally taken from sash.
 *
 * Permission to distribute this code under the GPL has been granted.
 * Majorly modified, and bugs fixed for busybox by Erik Andersen <andersee@debian.org> <andersen@lineo.com>
 */

#include "internal.h"
#ifdef BB_DD

const char dd_usage[] = 
"Copy a file, converting and formatting according to options\n\
\n\
usage: [if=name] [of=name] [bs=n] [count=n]\n\
\tif=FILE\tread from FILE instead of stdin\n\
\tof=FILE\twrite to FILE instead of stout\n\
\tbs=n\tread and write N bytes at a time\n\
\tcount=n\tcopy only n input blocks\n\
\n\
BYTES may be suffixed: by k for x1024, b for x512, and w for x2.\n";


#include <stdio.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <time.h>


#define	PAR_NONE	0
#define	PAR_IF		1
#define	PAR_OF		2
#define	PAR_BS		3
#define	PAR_COUNT	4


typedef	struct
{
	const char *	name;
	int		value;
} PARAM;


static const PARAM	params[] =
{
	{"if",		PAR_IF},
	{"of",		PAR_OF},
	{"bs",		PAR_BS},
	{"count",	PAR_COUNT},
	{NULL,		PAR_NONE}
};


static	long	getNum(const char * cp);

extern int
dd_main (struct FileInfo *unused, int argc, char **argv)
{
	const char *	str;
	const PARAM *	par;
	const char *	inFile;
	const char *	outFile;
	char *		cp;
	int		inFd;
	int		outFd;
	int		inCc=0;
	int		outCc;
	int		blockSize;
	long		count;
	long		intotal;
	long		outTotal;
	unsigned char*	buf;
	unsigned char	localBuf[BUF_SIZE];

	inFile = NULL;
	outFile = NULL;
	blockSize = 512;
	count = 1;


	while (--argc > 0)
	{
		str = *++argv;
		cp = strchr(str, '=');

		if (cp == NULL)
		{
			fprintf(stderr, "Bad dd argument\n");
			goto usage;
		}

		*cp++ = '\0';

		for (par = params; par->name; par++)
		{
			if (strcmp(str, par->name) == 0)
				break;
		}

		switch (par->value)
		{
			case PAR_IF:
				if (inFile)
				{
					fprintf(stderr, "Multiple input files illegal\n");
					goto usage;
				}
	
				//fprintf(stderr, "if=%s\n", cp);
				inFile = cp;
				break;

			case PAR_OF:
				if (outFile)
				{
					fprintf(stderr, "Multiple output files illegal\n");
					goto usage;
				}

				//fprintf(stderr, "of=%s\n", cp);
				outFile = cp;
				break;

			case PAR_BS:
				blockSize = getNum(cp);
				//fprintf(stderr, "bs=%d\n", blockSize);

				if (blockSize <= 0)
				{
					fprintf(stderr, "Bad block size value\n");
					goto usage;
				}

				break;

			case PAR_COUNT:
				count = getNum(cp);
				//fprintf(stderr, "count=%ld\n", count);

				if (count < 0)
				{
					fprintf(stderr, "Bad count value\n");
					goto usage;
				}

				break;

			default:
				goto usage;
		}
	}

	buf = localBuf;

	if (blockSize > sizeof(localBuf))
	{
		buf = malloc(blockSize);

		if (buf == NULL)
		{
			fprintf(stderr, "Cannot allocate buffer\n");
			return 1;
		}
	}

	intotal = 0;
	outTotal = 0;

	if (inFile == NULL)
	    inFd = STDIN;
	else
	    inFd = open(inFile, 0);

	if (inFd < 0)
	{
		perror(inFile);

		if (buf != localBuf)
			free(buf);

		return 1;
	}

	if (outFile == NULL)
	    outFd = STDOUT;
	else
	    outFd = creat(outFile, 0666);

	if (outFd < 0)
	{
		perror(outFile);
		close(inFd);

		if (buf != localBuf)
			free(buf);

		return 1;
	}

	while ( outTotal < count*blockSize )
	{
		inCc = read(inFd, buf, blockSize);
		if (inCc < 0) {
		    perror(inFile);
		    goto cleanup;
		}
		//fprintf(stderr, "read in =%d\n", inCc);
		intotal += inCc;
		cp = buf;


		while ( intotal > outTotal )
		{
			if (outTotal+inCc > count*blockSize)
			    inCc=count*blockSize-outTotal;
			outCc = write(outFd, cp, inCc);
			if (outCc < 0)
			{
				perror(outFile);
				goto cleanup;
			}
			//fprintf(stderr, "wrote out =%d\n", outCc);

			inCc -= outCc;
			cp += outCc;
			outTotal += outCc;
			//fprintf(stderr, "outTotal=%ld\n", outTotal);
		}
	}

	if (inCc < 0)
		perror(inFile);

cleanup:
	close(inFd);

	if (close(outFd) < 0)
		perror(outFile);

	if (buf != localBuf)
		free(buf);

	printf("%ld+%d records in\n", intotal / blockSize,
		(intotal % blockSize) != 0);

	printf("%ld+%d records out\n", outTotal / blockSize,
		(outTotal % blockSize) != 0);
	return 0;
usage:
	
	fprintf(stderr, "%s", dd_usage);
	return 1;
}


/*
 * Read a number with a possible multiplier.
 * Returns -1 if the number format is illegal.
 */
static long
getNum(const char * cp)
{
	long	value;

	if (!isDecimal(*cp))
		return -1;

	value = 0;

	while (isDecimal(*cp))
		value = value * 10 + *cp++ - '0';

	switch (*cp++)
	{
		case 'k':
			value *= 1024;
			break;

		case 'b':
			value *= 512;
			break;

		case 'w':
			value *= 2;
			break;

		case '\0':
			return value;

		default:
			return -1;
	}

	if (*cp)
		return -1;

	return value;
}

#endif
/* END CODE */