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/* vi: set sw=4 ts=4: */
/*
* Mini dd implementation for busybox
*
* Copyright (C) 1999, 2000 by Lineo, inc.
* Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
*
* Based in part on code taken from sash.
* Copyright (c) 1999 by David I. Bell
* Permission is granted to use, distribute, or modify this source,
* provided that this copyright notice remains intact.
*
* Permission to distribute this code under the GPL has been granted.
*
* 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 "internal.h"
#include <features.h>
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
#include <inttypes.h>
#else
typedef unsigned long long int uintmax_t;
#endif
static const char dd_usage[] =
"dd [if=FILE] [of=FILE] [bs=N] [count=N] [skip=N] [seek=N]\n"
#ifndef BB_FEATURE_TRIVIAL_HELP
"\nCopy a file, converting and formatting according to options\n\n"
"\tif=FILE\tread from FILE instead of stdin\n"
"\tof=FILE\twrite to FILE instead of stdout\n"
"\tbs=N\tread and write N bytes at a time\n"
"\tcount=N\tcopy only N input blocks\n"
"\tskip=N\tskip N input blocks\n"
"\tseek=N\tskip N output blocks\n"
"\n"
"Numbers may be suffixed by w (x2), k (x1024), b (x512), or M (x1024^2)\n"
#endif
;
extern int dd_main(int argc, char **argv)
{
char *inFile = NULL;
char *outFile = NULL;
char *cp;
int inFd;
int outFd;
int inCc = 0;
int outCc;
long blockSize = 512;
uintmax_t skipBlocks = 0;
uintmax_t seekBlocks = 0;
uintmax_t count = (uintmax_t) - 1;
uintmax_t intotal;
uintmax_t outTotal;
unsigned char *buf;
argc--;
argv++;
/* Parse any options */
while (argc) {
if (inFile == NULL && (strncmp(*argv, "if", 2) == 0))
inFile = ((strchr(*argv, '=')) + 1);
else if (outFile == NULL && (strncmp(*argv, "of", 2) == 0))
outFile = ((strchr(*argv, '=')) + 1);
else if (strncmp("count", *argv, 5) == 0) {
count = getNum((strchr(*argv, '=')) + 1);
if (count <= 0) {
fprintf(stderr, "Bad count value %s\n", *argv);
goto usage;
}
} else if (strncmp(*argv, "bs", 2) == 0) {
blockSize = getNum((strchr(*argv, '=')) + 1);
if (blockSize <= 0) {
fprintf(stderr, "Bad block size value %s\n", *argv);
goto usage;
}
} else if (strncmp(*argv, "skip", 4) == 0) {
skipBlocks = getNum((strchr(*argv, '=')) + 1);
if (skipBlocks <= 0) {
fprintf(stderr, "Bad skip value %s\n", *argv);
goto usage;
}
} else if (strncmp(*argv, "seek", 4) == 0) {
seekBlocks = getNum((strchr(*argv, '=')) + 1);
if (seekBlocks <= 0) {
fprintf(stderr, "Bad seek value %s\n", *argv);
goto usage;
}
} else {
goto usage;
}
argc--;
argv++;
}
buf = xmalloc(blockSize);
intotal = 0;
outTotal = 0;
if (inFile == NULL)
inFd = fileno(stdin);
else
inFd = open(inFile, 0);
if (inFd < 0) {
/* Note that we are not freeing buf or closing
* files here to save a few bytes. This exits
* here anyways... */
/* free(buf); */
fatalError( inFile);
}
if (outFile == NULL)
outFd = fileno(stdout);
else
outFd = open(outFile, O_WRONLY | O_CREAT | O_TRUNC, 0666);
if (outFd < 0) {
/* Note that we are not freeing buf or closing
* files here to save a few bytes. This exits
* here anyways... */
/* close(inFd);
free(buf); */
fatalError( outFile);
}
lseek(inFd, skipBlocks * blockSize, SEEK_SET);
lseek(outFd, seekBlocks * blockSize, SEEK_SET);
//
//TODO: Convert to using fullRead & fullWrite
// from utility.c
// -Erik
while (outTotal < count * blockSize) {
inCc = read(inFd, buf, blockSize);
if (inCc < 0) {
perror(inFile);
goto cleanup;
} else if (inCc == 0) {
goto cleanup;
}
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;
} else if (outCc == 0) {
goto cleanup;
}
inCc -= outCc;
cp += outCc;
outTotal += outCc;
}
}
if (inCc < 0)
perror(inFile);
cleanup:
/* Note that we are not freeing memory or closing
* files here, to save a few bytes. */
#if 0
close(inFd);
close(outFd);
free(buf);
#endif
printf("%ld+%d records in\n", (long) (intotal / blockSize),
(intotal % blockSize) != 0);
printf("%ld+%d records out\n", (long) (outTotal / blockSize),
(outTotal % blockSize) != 0);
exit(TRUE);
usage:
usage(dd_usage);
}
|
