diff options
Diffstat (limited to 'dd.c')
| -rw-r--r-- | dd.c | 307 |
1 files changed, 307 insertions, 0 deletions
@@ -0,0 +1,307 @@ +/* + * 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 */ + |