HP 3000 Manuals

Message Catalogs:Programmer's Guide

Reading Messages 

The CATREAD intrinsic reads the message specified by the set and message
number.  When you use CATREAD to read messages, the message facility
fetches the message from a message catalog, inserts parameters (if
specified), and then routes the message to a file or returns the message
in a buffer to the calling program.  The syntax for the CATREAD intrinsic
is:
  msglength := CATREAD (catindex, setnum, msgnum, catstatus, 
  buffer, buffersize, parm1, parm2, parm3, parm4, 
  parm5, msgdest);

The functional return, msglength, receives the length of the message in
bytes.  The catindex parameter refers to the catalog identifier you
received from CATOPEN. The parameters, setnum and msgnum specify the set
and message number of the message to be output.  The catstatus parameter
tells you if the CATOPEN call resulted in error, and, if so, what the
error is.  The optional parameters, buffer and buffersize, give the
buffer to put the message in and the size of the buffer, respectively.
The substitution parameters, parm1 through parm5, contain character
strings to be inserted into the message at run time.  The file number to
which the message may be sent is given in msgdest.

Parameter Substitution 

Parameters may be inserted into the message read from the catalog.
Parameter substitution is used when a message output contains information
only known at run time.  The parameters are passed to the message with
the param1, param2, param3, param4, and param5 parameters in the CATREAD
intrinsic and are inserted in the message wherever an "!" is found.
Parameters are inserted from left to right in positional parameter
substation and in the numerical position indicated in numerical parameter
substitution.  In either case, if param(n) is included in the CATREAD
call, param(n-1) must be present (that is, you cannot specify
param3 unless param1 and parm2 are specified.  Refer to "Parameter
Substitutions" in Chapter 2, for more information about parameter
substitution.  All substitutional parameters are passed as strings that
must terminate with an ASCII null character.

Message Output 

Messages may be output to a buffer or a file.  If you output to a buffer,
you specify the buffer and buffer size with the buffer and the buffersize 
parameters.  To output to a file, you specify the file number (returned
from HPFOPEN) and message length with the msgdest and the buffersize 
parameters.  To output to $STDLIST, use a file number of 0 (zero).

To output message #400 from set #13 to $STDLIST, a call to the CATREAD
intrinsic is done as follows:

          var
            Msglength: SHORTINT;
            Catindex : INTEGER;  {Returned by CATOPEN}
            Setnum   : SHORTINT;
            Msgnum   : SHORTINT;
            Catstatus: Packed array [1..2] of SHORTINT;
            Parm_1,
            Parm_2   : STRING [ 5 ];
            Msgdest  : SHORTINT;
            Dumy     : INTEGER;

          Setnum := 13;
          Msgnum := 400;
          Msgdest := 0; {Output to $STDLIST}
          Parm_1 := 'MARY';
          Parm_2 :='3';

          {Append ASCII null}
          STRWRITE (Parm_1, (STRLEN(Parm_1)+1), Dumy, CHR(0));
          STRWRITE (Parm_2, (STRLEN(Parm_2)+1), Dumy, CHR(0));
          Msglength := CATREAD (Catindex, Setnum, Msgnum,
             Catstatus,,, Parm_1, Parm_2,,,, Msgdest);

For detailed information about the CATREAD intrinsic, refer to the MPE XL
Intrinsics Reference Manual (32650-90028).

MPE/iX 5.0 Documentation