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Re: 19990512: ingest of a teletype file into LDM?
- Subject: Re: 19990512: ingest of a teletype file into LDM?
- Date: Fri, 14 May 1999 14:05:01 -0600 (MDT)
Jeff,
The simplest solution would be to use new afos code that will create an
WMO type header with the AFOS feedtype. I know this is a kuldge but it
should work because the tty format is like AFOS. The alternative would be
to use the new afos code as a template and make an EXP feedtype. This
probably would require modifying pqing.c, creating tty.c and tty.h and
more.
Robb...
On Fri, 14 May 1999, Unidata Support wrote:
>
> ------- Forwarded Message
>
> >cc: address@hidden
> >From: Jeff Ator <address@hidden>
> >Subject: ingest of a teletype file into LDM?
> >Organization: National Centers for Environmental Prediction
> >Keywords: 199905121231.GAA08153 LDM teletype
>
> Hello,
>
> On our public ftp server is a copy of a file that we would like to be
> able to ingest into our LDM (version 5.0.5). The file is from South
> Africa and appears to contain WMO bulletins in a teletype (tty) format,
> with a ZCZC beginning and NNNN end. In peeking through the LDM source
> code, it appears that there is the capability (via
> pqing/afos_message.c) to ingest AFOS pils that are in teletype format,
> but we couldn't find anything comparable for WMO bulletins. Does such a
> utility exist and, if so, could you point me to it and/or offer other
> suggestions? To help you investigate, a sample file is on our public
> ftp server. FTP to 140.90.50.22 and login as anonymous (you'll be
> prompted for your email address as a password). cd to pub/incomming,
> and the file is "messages_text" (be sure to use binary ftp!).
>
> Thanks very much for any help you can provide!
>
> Sincerely,
> __________________________________
>
> Jeffrey B. Ator
>
> National Centers for
> Environmental Prediction
> Central Operations
> 5200 Auth Road, Rm. 307
> Camp Springs, MD 20746
>
> Phone: (301) 763-8000, Ext. 7104
> Fax: (301) 763-8381
>
> E-Mail: address@hidden
>
> __________________________________
>
>
>
> ------- End of Forwarded Message
>
===============================================================================
Robb Kambic Unidata Program Center
Software Engineer III Univ. Corp for Atmospheric Research
address@hidden WWW: http://www.unidata.ucar.edu/
===============================================================================
/*
* Copyright 1995, University Corporation for Atmospheric Research
* See ../COPYRIGHT file for copying and redistribution conditions.
*/
/* $Id: afos_message.c,v 1.39 1999/04/20 22:25:42 davis Exp $ */
/*
* Routines to handle AFOS messages.
* Thanks to NWS personnel, who shared their ldm3 mods and
* other info.
* N.B. This module prepared without any supporting definitions
* or AFOS documentation.
*/
#include <ldmconfig.h>
#include <string.h>
#include <ctype.h>
#include "xbuf.h"
#include "tokens.h"
#include "afos_message.h"
#include "ulog.h"
static int seqno = 0;
static int zczc_missed = 0;
static int nnnn_missed = 0;
static int unrecognizable = 0;
void
afos_stats(void)
{
unotice(" AFOS Messages seen: %8d", seqno - unrecognizable);
unotice(" Errors: lone ZCZC: %8d", nnnn_missed);
unotice(" lone NNNN: %8d", zczc_missed);
unotice(" Unrecognizable: %8d", unrecognizable);
}
/*
* Set time stamp and hook up body of message
*/
static afos_message *
init_afos_message(
xbuf *buf, /* should be a clone ! */
afos_message *mess
)
{
mess->len = buf->cnt;
mess->msg = buf->get;
if( set_timestamp(&mess->arrival) != 0)
return NULL;
return mess;
}
/*
* skip up to the first Upper case char and get the rest of the line
*/
static int
nextUcaseLine(xbuf *buf, char *str, int maxlen)
{
int ch;
do{
ch = nextc(buf);
if(ch == EOB)
break;
}while(!isascii(ch) || !isupper(ch));
unnextc(buf,ch);
return( get_line(buf, str, maxlen) );
}
#define MIN_AFOS_MSG_LEN 14 /* wild ass guess */
static int
get_afos_message(xbuf *buf, afos_message *mess)
{
int zczc_missing = 0;
init_afos_message(buf, mess);
/* DEBUG */
if(mess->len < MIN_AFOS_MSG_LEN)
{
uerror("new_afos_message: length %d too short", mess->len);
goto err;
}
if(!hasSTR(buf, "ZCZC"))
{
/* not fatal, complain later */
zczc_missing = 1;
}
if(nextUcaseLine(buf, mess->ident, 12) == EOB) goto err;
{
/*
* Skip white space and (maybe) the next two bytes.
* What do they mean?
*/
int ch;
do{
ch = nextc(buf);
} while((isascii(ch) && !isgraph(ch)));
if(isascii(ch))
unnextc(buf, ch);
else
ch = nextc(buf);
}
{
/* optional */
wmo_header_t wmo_hdr;
dtime time;
wmo_hdr.time = &time;
if(get_wmo_header(buf, &wmo_hdr) != NULL
&& isupper(wmo_hdr.TT[0])
&& isupper(wmo_hdr.TT[1])
&& isupper(wmo_hdr.AA[0])
&& isupper(wmo_hdr.CCCC[0])
)
{
size_t len = strlen(mess->ident);
sprintf(&mess->ident[len],
" (%s)", s_wmo_header(&wmo_hdr));
}
}
if(zczc_missing)
{
uerror(" Missing ZCZC: %6s %03d %8d %s",
"AFOS",
seqno,
mess->len,
mess->ident);
}
if(memcmp(&mess->msg[mess->len -4], "NNNN", 4) != 0)
{
uerror(" Missing NNNN: %6s %03d %8d %s",
"AFOS",
seqno,
mess->len,
mess->ident);
/* Fatal, They will send it again */
return -1;
}
return 0;
err:
unrecognizable++;
uerror("Unrecognizable: %5s %03d %8d",
"AFOS",
seqno,
buf->cnt);
return -1;
}
extern void toClients(timestampt arrival,
unsigned seqno,
const char *ident,
unsigned len,
const char *buf);
static void
afos_send_buf(xbuf *buf, int backoff)
{
xbuf clone[1];
afos_message mess[1];
seqno++;
clone_xbuf(buf,clone, backoff);
if(get_afos_message(clone, mess) != 0)
return;
/* else, we got something */
toClients(mess->arrival,
seqno,
mess->ident,
(unsigned) mess->len, (char *)mess->msg);
}
int
scan_afos(xbuf *buf)
{
int sent = 0;
int ch;
static enum afos_l_state {
GND,
Z_,
Z_C_,
Z_C_Z_,
N_,
N_N_,
N_N_N_
} lstate = GND;
static enum afos_state {
START,
HEADER_SEEN,
TRAILER_SEEN
} state = START;
while ((ch = nextc(buf)) != EOB)
{
switch (ch) {
case 'Z':
if(lstate == Z_C_)
lstate = Z_C_Z_;
else
lstate = Z_;
break;
case 'C':
if(lstate == Z_)
lstate = Z_C_;
else if(lstate == Z_C_Z_ )
{
/* Z_C_Z_C */
if(state == HEADER_SEEN)
{
/* missing trailer */
nnnn_missed++;
udebug("Missing NNNN trailer");
afos_send_buf(buf, 4);
sent = 1;
}
justify_xbuf(buf, 4);
state = HEADER_SEEN;
lstate = GND;
}
break;
case 'N':
switch (lstate) {
case N_N_N_ :
/* N_N_N_N */
if(state == TRAILER_SEEN)
{
/* missing header */
zczc_missed++;
udebug("Missing ZCZC header");
}
afos_send_buf(buf, 0);
sent = 1;
justify_xbuf(buf, 0);
state = TRAILER_SEEN;
lstate = GND;
break;
case N_N_ :
lstate = N_N_N_;
break;
case N_ :
lstate = N_N_;
break;
default :
lstate = N_;
break;
} /* lstate switch */
break;
default :
lstate = GND;
break;
} /* ch switch */
} /* input character loop */
return sent;
}
/*
* Copyright 1995, University Corporation for Atmospheric Research
* See ../COPYRIGHT file for copying and redistribution conditions.
*/
/* $Id: afos_message.h,v 1.28 1996/09/13 16:48:07 davis Exp $ */
#ifndef _AFOS_MESSAGE_H_
#define _AFOS_MESSAGE_H_
#include "timestamp.h"
#include "xbuf.h"
#include "wmo_header.h"
/* size of the buffer for 9 character AFOS header */
#define MAX_AFOS_HLEN 16 /* actually, its 9 + 1 */
#define MAX_WMO_HLEN 24 /* actually, its 22 +1 */
/*
* AFOS Message
*/
typedef struct {
timestampt arrival; /* arrival time */
char ident[MAX_AFOS_HLEN +MAX_WMO_HLEN + 4]; /* AFOS header and more */
unsigned char *msg; /* the whole message */
size_t len;
} afos_message;
extern void afos_stats(void);
extern int scan_afos(xbuf *buf);
#endif /* _AFOS_MESSAGE_H_ */
