busybox/dd.c
Erik Andersen 4d1d0113fd Reworked the source so it will compile and run under glibc 2.0.7
and linux kernel 2.0.36 (though the dubious reasons why someone
would want to do that defy imagination ;)
 -Erik
1999-12-17 18:44:15 +00:00

195 lines
4.5 KiB
C

/*
* Mini dd implementation for busybox
*
* Copyright (C) 1999 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=name] [of=name] [bs=n] [count=n]\n\n"
"Copy 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 stout\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"
"\n"
"BYTES may be suffixed by w (x2), k (x1024), b (x512), or m (x1024^2).\n";
extern int dd_main (int argc, char **argv)
{
const char *inFile = NULL;
const char *outFile = NULL;
char *cp;
int inFd;
int outFd;
int inCc = 0;
int outCc;
size_t blockSize = 512;
//uintmax_t skipBlocks = 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;
}
}
#if 0
else if (strncmp(*argv, "skip", 4) == 0) {
skipBlocks = atoi( *argv);
if (skipBlocks <= 0) {
fprintf (stderr, "Bad skip value %d\n", skipBlocks);
goto usage;
}
}
#endif
else {
goto usage;
}
argc--;
argv++;
}
buf = malloc (blockSize);
if (buf == NULL) {
fprintf (stderr, "Cannot allocate buffer\n");
exit( FALSE);
}
intotal = 0;
outTotal = 0;
if (inFile == NULL)
inFd = fileno(stdin);
else
inFd = open (inFile, 0);
if (inFd < 0) {
perror (inFile);
free (buf);
exit( FALSE);
}
if (outFile == NULL)
outFd = fileno(stdout);
else
outFd = creat (outFile, 0666);
if (outFd < 0) {
perror (outFile);
close (inFd);
free (buf);
exit( FALSE);
}
//lseek(inFd, skipBlocks*blockSize, SEEK_SET);
//
//TODO: Convert to using fullRead & fullWrite
// from utilitity.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:
close (inFd);
close (outFd);
free (buf);
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);
}