C/C++ Users Group Library 1996 July/C-C++ Users Group Library July 1996.iso/vol_100/170_01/dump2.c

C/C++ Source or Header | 1980-01-01 | 5.3 KB | 184 lines

/*  dump.c  (10/83)  Debug style dump of a file from any starting position.


  Usage: dump filespec [block [page]] | [segment:[offset]] [count]
     Where a block is 64K bytes and a page is 256 bytes.
     Segment:offset are standard 8086 notation in hexadecimal.
     Count is the number of bytes to dump in decimal.

   dump b:\calc\data.dbm 1 16
    Positions file to absolute offset of 1000:1000 or 69632.
   dump bigfile :4F0 256
    Positions file to absolute offset of 4F0H or 1264 and
    dumps 256 bytes.

     The original source for dump was found on Lynn Long's BBS in Tulsa.  I
modified it to include file positioning.  It has proven to be a great tool at
times when I have to work with binary files that often exceed several million
characters.
   I have been using the Lattice 'C' compiler for about a year now and have
been very pleased with it.  I have re-written the level 1 I/O routines to take
advantage of DOS 2.0 path names, etc. and modified the _main module to allow
me to load and execute programs from within 'c'.

            Ted Reuss     c/o South Texas Software, Inc.
          Home: 713/961-3926      4544 Post Oak Place, Suite 176
          Offi: 713/877-8205      Houston, Tx 77027

*/
#include <stdio.h>
#include <ctype.h>        /* Lattice character type macros */

#define FAIL        1
#define SUCCESS     0
#define TRUE      (-1)
#define FALSE        0
#define NULL        0        /* null pointer value */
#define FOREVER     for (;;)
#define PAUSE        if (getch()=='\0') getch();
#define STDIN        0
#define STDOUT        1
#define STDERR        2

#define BUFSIZE 512
typedef unsigned    ushort;
typedef int        void;

int _fmode = 0x8000;        /* Lattice 'c' - forces binary I/O */
extern short errno;        /* DOS 2.0 error number */
long lseek();

char   buffer[BUFSIZE];     /* input buffer */
ushort block = 0;        /* block number ( 64k bytes/block ) */
ushort page = 0;        /* page number ( 256 bytes/page ) */
ushort segment = 0;
ushort offset = 0;
long   filpos = 0;        /* beginning file position */
long   count = 0x7FFFFFFFL;    /* number of bytes to dump */

main(argc,argv)         /* DUMP ENTRY */
int  argc;
char *argv[];
{
   char c;
   ushort i, numin, tot, file, cfrom, flag = 0;

   if (argc < 2)
      abort( "Usage:dump filespec [block [page]] | [seg:[ofs]]", 0, 0 );

   if ((file = open( argv[1], 0 )) == -1)
      abort( "cannot open", argv[1], errno );

   if (argc > 2) {
      if ((flag = stpchr( argv[2], ':' )) != NULL) {
     i = stch_i( argv[2], &segment );
     stch_i( argv[2]+i+1, &offset );
      }
      if (sscanf( argv[2], "%d", &block ) != 1)
     abort( "invalid block", argv[2], 0 );
   }
   if (argc > 3)
      if (sscanf( argv[3], "%d", &page ) != 1)
     abort( "invalid page", argv[3], 0 );

   if ( flag ) {
      filpos = (long)segment*16L + (long)offset;
      tot = offset;
   }
   else {
      filpos = (block * 65536L) + (page * 256);
      tot = page * 256;
      segment = block * 4096;
   }

   if (lseek( file, filpos, 0 ) == -1L)
      abort( "positioning to", argv[2], errno );

   if (argc > 4)
      if (sscanf( argv[4], "%ld", &count ) != 1)
     abort( "invalid count", argv[4], 0 );


   do {                    /* read & dump BUFSIZE bytes */
      numin = read( file, buffer, BUFSIZE );
      if (numin == -1)
     abort( "cannot read", argv[1], errno );
      cfrom=0;
      while (cfrom < numin) {

     ohw(segment);               /* print offset in hex */
     putchar(':');
     ohw(cfrom+tot);
     putchar(' ');

     for (i=0; i < 16; i++) {       /* print 16 bytes in hex */
        putchar(' ');
        ohb(buffer[cfrom++]);
     }

     putchar(' '); putchar(' '); putchar(' ');

     cfrom -= 16;
     for (i=0; i < 16; i++) {       /* print 16 bytes in ASCII */
        c = buffer[cfrom] & 0x7f;
        if ( isprint(c) )           /* if printable character */
           putchar(c);
        else
           putchar('.');               /* else print period */
        cfrom++;
     }

     putchar('\r'); putchar('\n');     /* print CR/LF */

     if ((count -= 16) <= 0)         /* is count exhausted? */
        exit(0);
      }                    /* end of while */
      tot += numin;
      if ( tot == 0 )
     segment += 4096;
   }                       /* end of do */
   while (numin == BUFSIZE);
}                       /* end of main */

void ohw(wrd)                 /*      print a word in hex     */
ushort wrd;
{
   ohb( wrd>>8 );
   ohb( wrd );
}

void ohb(byt)                 /*      print a byte in hex     */
char byt;
{
   onib( byt>>4 );
   onib( byt );
}

void onib(nib)             /*     print a nibble as a hex character   */
char nib;
{
   nib &= 15;
   putchar((nib >= 10) ? nib-10+'A': nib+'0');
}

void abort( msg1 ,msg2 ,errno)       /*  print error msg1, msg2, and nbr */
char *msg1,*msg2;           /*    Does not close files.  */
short errno;
{
   char stemp[10];

   write( STDERR, "ERR: ", 5 );
   if (msg1)
      write( STDERR, msg1, strlen(msg1) );
   if (msg2)
      write( STDERR, " ", 1 );
      write( STDERR, msg2, strlen(msg2) );
   if (errno)    {
      sprintf( stemp," #%d", errno );
      write( STDERR, stemp, strlen(stemp) );
   }
   write( STDERR, "\r\n", 2 );
   _exit( FAIL );
}
/** END DUMP **/