diff options
Diffstat (limited to 'dd.c')
| -rw-r--r-- | dd.c | 284 |
1 files changed, 140 insertions, 144 deletions
@@ -1,3 +1,4 @@ +/* vi: set sw=4 ts=4: */ /* * Mini dd implementation for busybox * @@ -40,164 +41,159 @@ typedef unsigned long long int uintmax_t; #endif static const char dd_usage[] = -"dd [if=name] [of=name] [bs=n] [count=n] [skip=n] [seek=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 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"; + "dd [if=name] [of=name] [bs=n] [count=n] [skip=n] [seek=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 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"; -extern int dd_main (int argc, char **argv) + +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; - 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; - } + const char *inFile = NULL; + const 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++; } - 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; - } + buf = malloc(blockSize); + if (buf == NULL) { + fprintf(stderr, "Cannot allocate buffer\n"); + exit(FALSE); } - else { - goto usage; + + intotal = 0; + outTotal = 0; + + if (inFile == NULL) + inFd = fileno(stdin); + else + inFd = open(inFile, 0); + + if (inFd < 0) { + perror(inFile); + free(buf); + exit(FALSE); } - 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 = open(outFile, O_WRONLY | O_CREAT | O_TRUNC, 0666); - - if (outFd < 0) { - perror (outFile); - close (inFd); - free (buf); - exit( FALSE); - } - - 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; + + if (outFile == NULL) + outFd = fileno(stdout); + else + outFd = open(outFile, O_WRONLY | O_CREAT | O_TRUNC, 0666); + + if (outFd < 0) { + perror(outFile); + close(inFd); + free(buf); + exit(FALSE); } - 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; + + 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); + 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); + 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); + usage(dd_usage); } - - |