Hello Francisco!

Thursday September 05 1996 17:12, Francisco Caselin Nava wrote to All:

 FN> Somebody knows the format of the headers and structure of *.MSG
 FN> files?

If you mean not FidoNet MSG files but OS/2 ones here is the source of MSG
file decompiler. Hope it will help (I've stripped russian message text
leaving only the program source). And yes, it is compiled with Watcom.

-------------------------------8<------------------------------------
Ä SU.OS2.PROG (2:5020/620) ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ SU.OS2.PROG Ä
 Msg  : 801 of 1092 -699
 From : Cyril Pertsev           2:5020/144.9   Sat 24 Aug 96 00:48
 To   : Vadim Yegorov                          Sat 24 Aug 96 06:30
 Subj : MSG format
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ
Hi, Vadim!

08:06, Saturday August 17 1996, Vadim Yegorov wrote to All:

[...message text skipped...]

=== Cut ===
/*
 * OS/2 Message file decompiler
 * written by Cyril Pertsev, Jul 1996
 */
#include 
#include 
#include 
#include 

#define MSGF_SIG "\xFFMKMSGF"

long
fsize ( FILE *file )
{
 long sav = ftell ( file ), size;

 fseek ( file, 0, SEEK_END );
 size = ftell ( file );
 fseek ( file, sav, SEEK_SET );
 return size;
}

void
main ( int argc, char *argv[] )
{
 FILE *fmsgf, *fout;
 char fname[ _MAX_FNAME + _MAX_EXT + 2 ];
 char *buf, compname[4];
 long filesz;
 short nmsgs, *toc;
 int   i;

 if ( argc < 2 )
 {
  fprintf ( stderr, "Usage %s \n", argv[0] );
  exit ( 1 );
 }

 if ( ( fmsgf = fopen ( argv[1], "rb" ) ) == NULL )
 {
  fprintf ( stderr, "Error opening input file %s [%s]\n",
            argv[1], strerror ( errno ) );
  exit ( 1 );
 }

 if ( ( buf = malloc ( filesz = fsize ( fmsgf ) ) ) == NULL )
 {
  fprintf ( stderr, "Can't allocate buffer memory\n" );
  exit ( 1 );
 }

 if ( fread ( buf, 1, filesz, fmsgf ) < filesz )
 {
  fprintf ( stderr, "Error reading input file [%s]\n",
            strerror ( errno ) );
  exit ( 1 );
 }
 if ( memcmp ( buf, MSGF_SIG, sizeof ( MSGF_SIG ) ) != 0 )
 {
  fprintf ( stderr, "This is not an OS/2 Message File\n" );
  exit ( 2 );
 }

 _splitpath ( argv[1], NULL, NULL, fname, NULL );
 strcat ( fname, ".cat" );
 if ( ( fout = fopen ( fname, "wb" ) ) == NULL )
 {
  fprintf ( stderr, "Error opening output file %s [%s]\n",
            fname, strerror ( errno ) );
  exit ( 1 );
 }

 // Get the component name (3 bytes at offset 8), store it as a 32-bit int
 *((long*)compname) = *((long*)&buf[8]);
 compname[3] = 0;
 // Get number of messages (2 bytes at offset 0B)
 nmsgs = *((short*)(buf + 0x0B));
 // Get table of contents (array of 16-bit ints at offset 1F)
 // each entry in an array is an offset of a corresponding msg within the file
 toc = (short*)(buf + 0x1F );

 fprintf ( fout, "%s\r\n", compname );
 for ( i = 0; i < nmsgs; i++ )
 {
  int msglen;
  char *msg;

  /* Get message length. If it is a last message, then length is until file end,
  else it is a difference between consecutive TOC entries (quite obvious, eh?).
  */
  msglen = ( i == nmsgs - 1 )? filesz - toc[i]: toc[i + 1] - toc[i];
  msg = malloc ( msglen );

  /* First char in a msg doesn't belong to a msg itself - it's a class of a
     message, so we skip it. Thus this toc[i]+1 expr.
  */
  memcpy ( msg, buf + toc[i] + 1, msglen );
  msg[msglen-1] = 0;

  /* print component name, msg number, msg class, and msg itself
     according to MKMSGF rules. RTFtoolkitM dox for them.
  */
  fprintf ( fout, "%s%4.4d%c: %s\r\n", compname, i + 1, buf[toc[i]],
            msg );
  free ( msg );
 }

 fclose ( fmsgf );
 fclose ( fout );
 free ( buf );
 exit ( 0 );
}
=== Cut ===

        Kika

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