2 * Mini dd implementation for busybox
4 * Copyright (C) 1999 by Lineo, inc.
5 * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
6 * based in part on code taken from sash.
8 * Copyright (c) 1999 by David I. Bell
9 * Permission is granted to use, distribute, or modify this source,
10 * provided that this copyright notice remains intact.
12 * Permission to distribute this code under the GPL has been granted.
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
37 static const char dd_usage[] =
38 "dd [if=name] [of=name] [bs=n] [count=n]\n\n"
39 "Copy a file, converting and formatting according to options\n\n"
40 "\tif=FILE\tread from FILE instead of stdin\n"
41 "\tof=FILE\twrite to FILE instead of stout\n"
42 "\tbs=n\tread and write N BYTES at a time\n"
43 "\tcount=n\tcopy only n input blocks\n"
44 //"\tskip=n\tskip n input blocks\n"
46 "BYTES may be suffixed: by k for x1024, b for x512, and w for x2.\n";
52 * Read a number with a possible multiplier.
53 * Returns -1 if the number format is illegal.
55 static long getNum (const char *cp)
64 while (isDecimal (*cp))
65 value = value * 10 + *cp++ - '0';
94 extern int dd_main (int argc, char **argv)
96 const char *inFile = NULL;
97 const char *outFile = NULL;
103 size_t blockSize = 512;
104 //uintmax_t skipBlocks = 0;
105 uintmax_t count = (uintmax_t)-1;
113 /* Parse any options */
115 if (inFile == NULL && (strncmp(*argv, "if", 2) == 0))
116 inFile=((strchr(*argv, '='))+1);
117 else if (outFile == NULL && (strncmp(*argv, "of", 2) == 0))
118 outFile=((strchr(*argv, '='))+1);
119 else if (strncmp("count", *argv, 5) == 0) {
120 count = getNum ((strchr(*argv, '='))+1);
122 fprintf (stderr, "Bad count value %s\n", *argv);
126 else if (strncmp(*argv, "bs", 2) == 0) {
127 blockSize = getNum ((strchr(*argv, '='))+1);
128 if (blockSize <= 0) {
129 fprintf (stderr, "Bad block size value %s\n", *argv);
134 else if (strncmp(*argv, "skip", 4) == 0) {
135 skipBlocks = atoi( *argv);
136 if (skipBlocks <= 0) {
137 fprintf (stderr, "Bad skip value %d\n", skipBlocks);
150 buf = malloc (blockSize);
152 fprintf (stderr, "Cannot allocate buffer\n");
160 inFd = fileno(stdin);
162 inFd = open (inFile, 0);
171 outFd = fileno(stdout);
173 outFd = creat (outFile, 0666);
182 //lseek(inFd, skipBlocks*blockSize, SEEK_SET);
183 while (outTotal < count * blockSize) {
184 inCc = read (inFd, buf, blockSize);
188 } else if (inCc == 0) {
194 while (intotal > outTotal) {
195 if (outTotal + inCc > count * blockSize)
196 inCc = count * blockSize - outTotal;
197 outCc = write (outFd, cp, inCc);
201 } else if (outCc == 0) {
219 printf ("%ld+%d records in\n", (long)(intotal / blockSize),
220 (intotal % blockSize) != 0);
221 printf ("%ld+%d records out\n", (long)(outTotal / blockSize),
222 (outTotal % blockSize) != 0);