#include <stdio.h>
#include <ctype.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>

int readsize(long offset,  long filesize, long pagesize)
{
   int left = filesize - offset;
   if ( left > pagesize )
      return (pagesize);
   else
      return (left);
}

void process( char * pszFileName )
{
   int fd;
   void * pmap;
   char * pBuf;
   char * pEnd;
   int fieldcount = 0;
   char ch = (char) NULL;
   char lastChar = (char) NULL;
   int filesize = 0;
   int readlen = 0;
   int offset = 0;
   long pagesize = 0;

   pagesize = sysconf(_SC_PAGE_SIZE);

   fd = open( pszFileName, O_RDONLY );

   filesize = lseek( fd, 0, SEEK_END );
   readlen = readsize( 0, filesize, pagesize );

   while ( readlen > 0 )
   {
      pmap = mmap( 0, readlen, PROT_READ, MAP_SHARED, fd, offset );
      pBuf = (char *)pmap;
      pEnd = (char *)pmap + readlen;

      while ( pBuf < pEnd )
      {
         ch = *pBuf++;
         if ( ch == '\n' )
         {
            printf("\n");
            fieldcount = 0;
            lastChar = (char)NULL;
            continue;
         }
         else if ( (!isspace(ch)) && (isspace(lastChar)))
            fieldcount++;
         else if ( (isspace(ch)) && (isspace(lastChar)))
            continue;

         switch ( fieldcount + 1 )
         {
               case 1:
               case 2:
               case 4:
               case 6:
               case 11:
               case 12:
               case 13:
                  printf("%c", ch);
                  break;
         }
         lastChar = ch;
      }

      munmap( pmap, readlen );
      offset = offset + readlen;
      readlen = readsize( offset, filesize, pagesize );
   }
}

main(int argc, char *argv[])
{
   if ( argc == 2 )
   {
      process( argv[1] );
   }
}