MQCFST - String parameter

Use this page to view the structure of an MQCFST parameter and the declarations for the following programming languages: C, COBOL, PL/I, RPG/ILE, S/390 assembler, and Visual Basic

The MQCFST structure describes a string parameter. Following the links to the declarations is a description of the fields making up the MQCFST structure:

C language
COBOL language
PL/I language ( z/OS® only)
RPG/ILE language ( IBM® i only)
System/390 assembler-language ( z/OS only)
Visual Basic language ( Windows only)

The MQCFST structure ends with a variable-length character string; see the String field for further details.

Type

Description:

Indicates that the structure type is MQCFST and describes a string parameter.

Data type:

MQLONG.

Value:

MQCFT_STRING: Structure defining a string.

StrucLength

Description:

Length in bytes of the MQCFST structure, including the string at the end of the structure (the String field).

Data type:

MQLONG.

Parameter

Description:

Identifies the parameter with a value that is contained in the structure.

Data type:

MQLONG.

Values:

Dependent on the event message.

CodedCharSetId

Description:

Coded character set identifier of the data in the String field.

Data type:

MQLONG.

StringLength

Description:

Length in bytes of the data in the String field; zero or greater.

Data type:

MQLONG.

String

Description:

The value of the parameter identified by the Parameter field.

In MQFMT_EVENT messages, trailing blanks can be omitted from string parameters (that is, the string may be shorter than the defined length of the parameter). StringLength gives the length of the string actually present in the message.

Data type:

MQCHAR x StringLength

Value:

The string can contain any characters that are in the character set defined by CodedCharSetId, and that are valid for the parameter identified by Parameter.

Language considerations:

The way that this field is declared depends on the programming language:

For the C programming language, the field is declared as an array with one element. Storage for the structure should be allocated dynamically, and pointers used to address the fields within it.
For the COBOL, PL/I, System/390 assembler, and Visual Basic programming languages, the field is omitted from the structure declaration. When an instance of the structure is declared, the user should include MQCFST in a larger structure, and declare additional fields following MQCFST, to represent the String field as required.

A null character in the string is treated as normal data, and does not act as a delimiter for the string. This means that when a receiving application reads an MQFMT_EVENT message, the receiving application receives all of the data specified by the sending application. The data may, of course, have been converted between character sets (for example, by the receiving application specifying the MQGMO_CONVERT option on the MQGET call).

C language declaration

typedef struct tagMQCFST {
  MQLONG  Type;            /* Structure type */
  MQLONG  StrucLength;     /* Structure length */
  MQLONG  Parameter;       /* Parameter identifier */
  MQLONG  CodedCharSetId;  /* Coded character set identifier */
  MQLONG  StringLength;    /* Length of string */
  MQCHAR  String[1];       /* String value - first
                              character */
 } MQCFST;

COBOL language declaration

**   MQCFST structure
  10 MQCFST.
**    Structure type
   15 MQCFST-TYPE           PIC S9(9) BINARY.
**    Structure length
   15 MQCFST-STRUCLENGTH    PIC S9(9) BINARY.
**    Parameter identifier
   15 MQCFST-PARAMETER      PIC S9(9) BINARY.
**    Coded character set identifier
   15 MQCFST-CODEDCHARSETID PIC S9(9) BINARY.
**    Length of string
   15 MQCFST-STRINGLENGTH   PIC S9(9) BINARY.

PL/I language declaration

dcl
 1 MQCFST based,
  3 Type           fixed bin(31), /* Structure type */
  3 StrucLength    fixed bin(31), /* Structure length */
  3 Parameter      fixed bin(31), /* Parameter identifier */
  3 CodedCharSetId fixed bin(31), /* Coded character set identifier */
  3 StringLength   fixed bin(31); /* Length of string */

RPG/ILE declaration ( IBM i only)

     D*..1....:....2....:....3....:....4....:....5....:....6....:....7..
     D* MQCFST Structure
     D*
     D* Structure type
     D  STTYP                  1      4I 0
     D* Structure length
     D  STLEN                  5      8I 0
     D* Parameter identifier
     D  STPRM                  9     12I 0
     D* Coded character set identifier
     D  STCSI                 13     16I 0
     D* Length of string
     D  STSTL                 17     20I 0

S/390 assembler-language declaration

MQCFST                         DSECT
MQCFST_TYPE                    DS   F        Structure type
MQCFST_STRUCLENGTH             DS   F        Structure length
MQCFST_PARAMETER               DS   F        Parameter identifier
MQCFST_CODEDCHARSETID          DS   F        Coded character set
*                                            identifier
MQCFST_STRINGLENGTH            DS   F        Length of string
MQCFST_LENGTH                  EQU  *-MQCFST Length of structure
                               ORG  MQCFST
MQCFST_AREA                    DS   CL(MQCFST_LENGTH)

Visual Basic language declaration

Type MQCFST
  Type As Long            ' Structure type
  StrucLength As Long     ' Structure length
  Parameter As Long       ' Parameter identifier
  CodedCharSetId As Long  ' Coded character set identifier
  StringLength As Long    ' Length of string
End Type