20150930-01

/*----------------------------------------------------------------------------
------------------------------ Part 0: contents ------------------------------
----------------------------------------------------------------------------*/

/*

Part 0: contents
Part 1: #includes
Part 2: #defines
Part 3: globals
Part 4: library function declarations
Part 5: function declarations
Part 6: library function definitions
Part 7: function definitions
Part 8: main()

*/

/*----------------------------------------------------------------------------
------------------------------ Part 1: #includes -----------------------------
----------------------------------------------------------------------------*/

#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

/*----------------------------------------------------------------------------
------------------------------ Part 2: #defines ------------------------------
----------------------------------------------------------------------------*/

#define BLOCK_SIZE 4096

#define Open(a,b,c) \
        OPen(__LINE__,a,b,c)

#define Lseek(a,b,c) \
        LSeek(__LINE__,a,b,c)

/*----------------------------------------------------------------------------
------------------------------- Part 3: globals ------------------------------
----------------------------------------------------------------------------*/

char *gl_errno_names[]=
{
  "NO_ERROR",
  "EPERM",
  "ENOENT",
  "ESRCH",
  "EINTR",
  "EIO",
  "ENXIO",
  "E2BIG",
  "ENOEXEC",
  "EBADF",
  "ECHILD",
  "EAGAIN or EWOULDBLOCK",
  "ENOMEM",
  "EACCES",
  "EFAULT",
  "ENOTBLK",
  "EBUSY",
  "EEXIST",
  "EXDEV",
  "ENODEV",
  "ENOTDIR",
  "EISDIR",
  "EINVAL",
  "ENFILE",
  "EMFILE",
  "ENOTTY",
  "ETXTBSY",
  "EFBIG",
  "ENOSPC",
  "ESPIPE",
  "EROFS",
  "EMLINK",
  "EPIPE",
  "EDOM",
  "ERANGE",
  "EDEADLK or EDEADLOCK",
  "ENAMETOOLONG",
  "ENOLCK",
  "ENOSYS",
  "ENOTEMPTY",
  "ELOOP",
  "quasi-EWOULDBLOCK (which is now error 11)",
  "ENOMSG",
  "EIDRM",
  "ECHRNG",
  "EL2NSYNC",
  "EL3HLT",
  "EL3RST",
  "ELNRNG",
  "EUNATCH",
  "ENOCSI",
  "EL2HLT",
  "EBADE",
  "EBADR",
  "EXFULL",
  "ENOANO",
  "EBADRQC",
  "EBADSLT",
  "quasi-EDEADLOCK (which is now error 35)",
  "EBFONT",
  "ENOSTR",
  "ENODATA",
  "ETIME",
  "ENOSR",
  "ENONET",
  "ENOPKG",
  "EREMOTE",
  "ENOLINK",
  "EADV",
  "ESRMNT",
  "ECOMM",
  "EPROTO",
  "EMULTIHOP",
  "EDOTDOT",
  "EBADMSG",
  "EOVERFLOW",
  "ENOTUNIQ",
  "EBADFD",
  "EREMCHG",
  "ELIBACC",
  "ELIBBAD",
  "ELIBSCN",
  "ELIBMAX",
  "ELIBEXEC",
  "EILSEQ",
  "ERESTART",
  "ESTRPIPE",
  "EUSERS",
  "ENOTSOCK",
  "EDESTADDRREQ",
  "EMSGSIZE",
  "EPROTOTYPE",
  "ENOPROTOOPT",
  "EPROTONOSUPPORT",
  "ESOCKTNOSUPPORT",
  "EOPNOTSUPP",
  "EPFNOSUPPORT",
  "EAFNOSUPPORT",
  "EADDRINUSE",
  "EADDRNOTAVAIL",
  "ENETDOWN",
  "ENETUNREACH",
  "ENETRESET",
  "ECONNABORTED",
  "ECONNRESET",
  "ENOBUFS",
  "EISCONN",
  "ENOTCONN",
  "ESHUTDOWN",
  "ETOOMANYREFS",
  "ETIMEDOUT",
  "ECONNREFUSED",
  "EHOSTDOWN",
  "EHOSTUNREACH",
  "EALREADY",
  "EINPROGRESS",
  "ESTALE",
  "EUCLEAN",
  "ENOTNAM",
  "ENAVAIL",
  "EISNAM",
  "EREMOTEIO",
  "EDQUOT",
  "ENOMEDIUM",
  "EMEDIUMTYPE"
};

/*----------------------------------------------------------------------------
-------------------- Part 4: library function declarations -------------------
----------------------------------------------------------------------------*/

void
Exit(int ar_status);

off_t
LSeek(int   ar_line,
      int   ar_fd,
      off_t ar_offset,
      int   ar_whence
     );

int
OPen(int         ar_line,
     char const *ar_pathname,
     int         ar_flags,
     int         ar_mode
    );

/*----------------------------------------------------------------------------
------------------------ Part 5: function declarations -----------------------
----------------------------------------------------------------------------*/

char *
get_errno_name(int ar_error_number);

void
oops_errno(int         ar_line,
           char const *ar_format,
           ...
          );

void
oops_plain(int         ar_line,
           char const *ar_format,
           ...
          );

void
oops_v(char const *ar_format,
       va_list     ar_args
      );

void
usage(int    ar_argc,
      char **ar_argv,
      FILE  *ar_phyle,
      int    ar_exit_code
     );

/*----------------------------------------------------------------------------
-------------------- Part 6: library function definitions --------------------
----------------------------------------------------------------------------*/

void
Exit(int ar_status)
{
  exit(ar_status);

} /* Exit() */

/*-------------------------------------------------------------------------- */

off_t
LSeek(int   ar_line,
      int   ar_fd,
      off_t ar_offset,
      int   ar_whence
     )
{
  off_t lo_result;

  lo_result=lseek(ar_fd,
                  ar_offset,
                  ar_whence
                 );

  if(lo_result==-1)
  {
    oops_errno(ar_line,
               "lseek(%d,%ld 0x%lX,%d)",
               ar_fd,
               ar_offset,
               ar_offset,
               ar_whence
              );
  }

  return lo_result;

} /* LSeek() */

/*-------------------------------------------------------------------------- */

int
OPen(int         ar_line,
     char const *ar_pathname,
     int         ar_flags,
     int         ar_mode
    )
{
  int lo_result;

  lo_result=open(ar_pathname,
                 ar_flags,
                 ar_mode
                );

  if(lo_result==-1)
  {
    oops_errno(ar_line,
               "open(\"%s\")",
               ar_pathname
              );
  }

  return lo_result;

} /* OPen() */

/*----------------------------------------------------------------------------
------------------------ Part 7: function definitions ------------------------
----------------------------------------------------------------------------*/

char *
get_errno_name(int ar_error_number)
{
  if((ar_error_number>=0) &&
     (ar_error_number<sizeof(gl_errno_names)/sizeof(gl_errno_names[0]))
    )
  {
    return gl_errno_names[ar_error_number];
  }
  else
  {
    return "[invalid error number]";
  }

} /* get_errno_name() */

/*--------------------------------------------------------------------------*/

void
oops_errno(int         ar_line,
           char const *ar_format,
           ...
          )
{
  va_list lo_arg_pointer;

  int     lo_error;

  lo_error=errno;

  fprintf(stderr,
          "error %d (%s) %s on line %d\nduring ",
          lo_error,
          get_errno_name(lo_error),
          strerror(lo_error),
          ar_line
         );

  va_start(lo_arg_pointer,
           ar_format
          );

  oops_v(ar_format,
         lo_arg_pointer
        );

  va_end(lo_arg_pointer);

  fprintf(stderr,"\n");

  Exit(2);

} /* oops_errno() */

/*--------------------------------------------------------------------------*/

void
oops_plain(int         ar_line,
           char const *ar_format,
           ...
          )
{
  va_list lo_arg_pointer;

  fprintf(stderr,
          "error on line %d:\n",
          ar_line
         );

  va_start(lo_arg_pointer,
           ar_format
          );

  oops_v(ar_format,
         lo_arg_pointer
        );

  va_end(lo_arg_pointer);

  fprintf(stderr,"\n");

  Exit(2);

} /* oops_plain() */

/*--------------------------------------------------------------------------*/

void
oops_v(char const *ar_format,
       va_list     ar_args
      )
{
  vfprintf(stderr,
           ar_format,
           ar_args
          );

} /* oops_v() */

/*--------------------------------------------------------------------------*/

void
usage(int    ar_argc,
      char **ar_argv,
      FILE  *ar_phyle,
      int    ar_exit_code
     )
{
  fprintf(ar_phyle,
          "usage:\n"
          "  %s file-or-block-device-name           exercise this device\n",
          ar_argv[0]
         );

  Exit(ar_exit_code);

} /* usage() */

/*----------------------------------------------------------------------------
------------------------------- Part 8: main() -------------------------------
----------------------------------------------------------------------------*/

int
main(int    ar_argc,
     char **ar_argv
    )
{
  int   lo_fd;

  char  lo_buffer[4];

  off_t lo_block_count;
  off_t lo_block_index;
  off_t lo_high_bit;
  off_t lo_mask;
  off_t lo_top_displacement;

  if(ar_argc!=2)
  {
    usage(ar_argc,
          ar_argv,
          stderr,
          1
         );
  }

  lo_fd=Open(ar_argv[1],
             O_RDONLY,
             0
            );

  lo_high_bit=1;

  while(lo_high_bit>0)
  {
    if(lseek(lo_fd,
             lo_high_bit,
             SEEK_SET
            )
       ==
       (off_t)-1
      )
    {
      lo_high_bit>>=1;

      break;
    }

    if(read(lo_fd,
            lo_buffer,
            1
           )
       !=
       1
      )
    {
      lo_high_bit>>=1;

      break;
    }

    lo_high_bit<<=1;
  }

  lo_top_displacement=lo_high_bit;

  for(lo_mask=lo_high_bit>>1;
      lo_mask;
      lo_mask>>=1
     )
  {
    if(lseek(lo_fd,
             lo_top_displacement | lo_mask,
             SEEK_SET
            )
       ==
       (off_t)-1
      )
    {
      continue;
    }

    if(read(lo_fd,
            lo_buffer,
            1
           )
       !=
       1
      )
    {
      continue;
    }

    lo_top_displacement |= lo_mask;
  }

  printf("%lld\n",lo_top_displacement);

  lo_block_count=(lo_top_displacement+1)/BLOCK_SIZE;

  for(lo_block_index=0;
      lo_block_index<lo_block_count/2;
      lo_block_index+=10000
     )
  {
    printf("%lld %lld\n",lo_block_index,(100*lo_block_index)/lo_block_count/2);

    Lseek(lo_fd,
          lo_block_index*BLOCK_SIZE,
          SEEK_SET
         );

    read(lo_fd,
         lo_buffer,
         1
        );

    Lseek(lo_fd,
          (lo_block_index+lo_block_count/2)*BLOCK_SIZE,
          SEEK_SET
         );

    read(lo_fd,
         lo_buffer,
         1
        );
  }

  return 0;

} /* main() */



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