Thread: ISO 8583 Message Parser in C?

Dear Friends ,
Could you please help me to develope a ISO 8583 Message Parser in C or any body is having it .
Thanks in advance
Nadeer

We did the ISO parsing in Oracle PL/SQL , Now palnning to move to Unix/C ,
the actual issue is , in PL/SQL the Filed lenght/Attribute/type are stored in the Table and the parser reads the table to parse the fields.
Could please help me how ro achieve this in C
and pl/SQL
Here some part of it for your reference.

Code:

FUNCTION Convertx2b(  p_inXbit  IN VARCHAR2, p_Bbit OUT  VARCHAR2) RETURN  BOOLEAN IS
/*=========================================================================================================
Converting the HEX Values into Binary .
==========================================================================================================*/

  v_cur_pos       INTEGER DEFAULT 1;
  v_tot_length    INTEGER;
  v_iso_bin       VARCHAR2(4);
  v_count	  NUMBER(2):=1;
  v_cur_value     VARCHAR2(1);

BEGIN
  v_tot_length := LENGTH(p_inXbit); --total length of Hexadecimal bitmap

  --loop through hexadecimal values and replace them one by one
  FOR i IN 2..(v_tot_length+1) LOOP

      v_cur_value:=SUBSTR(p_inXbit,v_COUNT,1);
      BEGIN
	SELECT  DECODE(v_cur_value,'0', '0000',
                                   '1', '0001',
                                   '2', '0010',
                                   '3', '0011',
	                           '4', '0100',
	                           '5', '0101',
	                           '6', '0110',
	                           '7', '0111',
	                           '8', '1000',
	                           '9', '1001',
	                           'A', '1010',
	                           'B', '1011',
	                           'C', '1100',
	                           'D', '1101',
	                           'E', '1110',
	                           'F', '1111',
     		                   'ERR')
	INTO v_iso_bin FROM dual ;
      EXCEPTION
            WHEN OTHERS THEN
               RETURN FALSE;
      END;
      	 IF v_iso_bin <> 'ERR' THEN		--junb
	    p_Bbit:=p_Bbit||TO_CHAR(v_iso_bin); --construct binary output
	 ELSE
	    RETURN FALSE;
	 END IF;
	    v_count:=v_count+1;
  END LOOP;

  RETURN TRUE; --if no errors
END;

/*====================================================================================================================
====================================================================================================================*/
PROCEDURE do_initialize
  IS
  BEGIN
    FOR i IN 1..128
    LOOP
      BEGIN
        p_msgrec(i) := NULL;
      EXCEPTION
        WHEN OTHERS THEN
        	out_bds_msg := '4202';
        	RAISE e_error;
	  END;
    END LOOP;
END; -->>initialize End
/*=================================================================================================================
====================================================================================================================*/

FUNCTION CHECK_FLDS( p_Bbit IN VARCHAR2, p_data IN VARCHAR2) RETURN BOOLEAN IS
/*===================================================================================================================
Checking  fields in the ISO BIT Message
=====================================================================================================================*/

  v_cur_pos      INTEGER DEFAULT 1;
  v_length       INTEGER;
  v_tot_length   INTEGER;
  v_len          INTEGER;
  v_iso_flds     ISO_FIELDS%ROWTYPE;

BEGIN
  v_tot_length := LENGTH(p_data); --length of data part
  v_len := LENGTH(p_Bbit);        --length of binary bitmap

/*loop through binary bitmap to populate fields*/
  FOR i IN 2..v_len LOOP
    IF  SUBSTR(p_Bbit,i,1)='1' THEN  --if it is 1 ,field is populated..get length.if 0 skip

      IF v_cur_pos > v_tot_length THEN
        p_msgrec(72) := 'END OF MESSAGE REACHED';
        RETURN FALSE;
      END IF;
      --get field properties from table
      BEGIN
        SELECT *
        INTO   v_iso_flds
        FROM   ISO_FIELDS
        WHERE  bit=i;

      EXCEPTION
	      WHEN NO_DATA_FOUND THEN
	           p_msgrec(72) := 'ISO 8583 REF TAB NOT SETUP. FLD NO.: '||TO_CHAR(i)||' ';
             RETURN FALSE;
      END;
      --get field length
      v_length := v_iso_flds.LENGTH;

--incase field format is LLVAR
      IF v_iso_flds.format='LLVAR' THEN

        BEGIN
          --get length of field from first 2 numbers
          v_length:=TO_NUMBER(SUBSTR(p_data,v_cur_pos,2));
        EXCEPTION
	        WHEN VALUE_ERROR THEN
	             p_msgrec(72) := 'NON-NUMERIC LENGTH VALUE FOR LLVAR. FIELD: '||v_iso_flds.name
                                ||' ';
               logData(to_char (systimestamp, 'hh24.mi.ss.ff3')||'NON-NUMERIC LENGTH VALUE FOR LLVAR. FIELD:->'||to_char(i)||v_iso_flds.name ||',CardNo'||p_msgrec(2)||'->MsgStanNo'||p_msgrec(11),'E');
	             RETURN  FALSE;
        END;

        IF v_length > v_iso_flds.LENGTH THEN
          p_msgrec(72) := 'LENGTH FOR LLVAR EXCEEDS MAX. FIELD: '
                       ||v_iso_flds.name||' ';
         logData(to_char (systimestamp, 'hh24.mi.ss.ff3')||'LENGTH FOR LLVAR EXCEEDS MAX. FIELD:->'||to_char(i)||v_iso_flds.name||',CardNo'||p_msgrec(2)||'->MsgStanNo'||p_msgrec(11),'E');
          RETURN FALSE;
        END IF;
        --skip first 2 numbers since they are length of field
        v_cur_pos:=v_cur_pos+2;

--incase field format is LLLVAR
      ELSIF v_iso_flds.format='LLLVAR' THEN

        BEGIN
          --get length of field from first 3 numbers
	        v_length:=TO_NUMBER(SUBSTR(p_data,v_cur_pos,3));
        EXCEPTION
	        WHEN VALUE_ERROR THEN
	             p_msgrec(72) := 'NNUM LENGTH VAL FOR LLLVAR. FLD: '|| v_iso_flds.name||' ';
               logData(to_char (systimestamp, 'hh24.mi.ss.ff3')||'NNUM LENGTH VAL FOR LLLVAR. FLD:->'||to_char(i)|| v_iso_flds.name||',CardNo'||p_msgrec(2)||'->MSgStanNo'||p_msgrec(11),'E');
          RETURN  FALSE;
        END;

	      IF v_length > v_iso_flds.LENGTH THEN
	         p_msgrec(72) := 'LGTH FOR LLLVAR EXCEEDS MAX. FIELD: '||v_iso_flds.name||' ';
           logData(to_char (systimestamp, 'hh24.mi.ss.ff3')||'LGTH FOR LLLVAR EXCEEDS MAX. FIELD:-> '||to_char(i)||v_iso_flds.name||',CardNo'||p_msgrec(2)||'->MsgStanNo'||p_msgrec(11),'E');
           RETURN FALSE;
        END IF;
        --skip first 3 numbers since they are length of field
    	  v_cur_pos:=v_cur_pos+3;
      END IF;


      p_msgrec(i)     :=   SUBSTR(p_data,v_cur_pos,v_length);
      v_cur_pos       :=   v_cur_pos+v_length;

    END IF;
  END LOOP;

 RETURN TRUE; --if no errors

END CHECK_FLDS;

am ready pay , posted a bid in rentacoder.com.
Nadeer