busybox/dd.c
Eric Andersen 9d3aba7b37 more stuff
1999-10-06 09:04:55 +00:00

308 lines
4.7 KiB
C

/*
* 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 (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 */