MQCFBS - PCF byte string parameter
The MQCFBS structure describes a byte-string parameter in a PCF message. The format name in the message descriptor is MQFMT_ADMIN.
When an MQCFBS structure is present, the Version field in the MQCFH structure at the start of the PCF must be MQCFH_VERSION_2 or greater.
In a user PCF message, the Parameter field has no significance, and can be used by the application for its own purposes.
The structure ends with a variable-length byte string; see the String field in the following section for further details.
Fields for MQCFBS
- Type (MQLONG)
- Structure type.
This indicates that the structure is an MQCFBS structure describing byte string parameter. The value must be:
- MQCFT_BYTE_STRING
- Structure defining a byte string.
- StrucLength (MQLONG)
- Structure length.
This is the length in bytes of the MQCFBS structure, including the variable-length string at the end of the structure (the String field). The length must be a multiple of four, and must be sufficient to contain the string; any bytes between the end of the string and the length defined by the StrucLength field are not significant.
The following constant gives the length of the fixed part of the structure, that is the length excluding the String field:- MQCFBS_STRUC_LENGTH_FIXED
- Length of fixed part of MQCFBS structure.
- Parameter (MQLONG)
- Parameter identifier.
This identifies the parameter with a value that is contained in the structure. The values that can occur in this field depend on the value of the Command field in the MQCFH structure; see MQCFH - PCF header for details. In user PCF messages (MQCFT_USER), this field has no significance.
The parameter is from the MQBACF_* group of parameters.
- StringLength (MQLONG)
- Length of string.
This is the length in bytes of the data in the string field; it must be zero or greater. This length does not need to be a multiple of four.
- String (MQBYTE x StringLength)
- String value.
This is the value of the parameter identified by the parameter field. The string is a byte string, and so is not subject to character-set conversion when sent between different systems.
Note: A null character in the string is treated as normal data, and does not act as a delimiter for the string
For MQFMT_ADMIN messages, if the specified string is shorter than the standard length of the parameter, the omitted characters are assumed to be nulls. If the specified string is longer than the standard length, it is an error.
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 must be allocated dynamically, and pointers used to address the fields within it.
- For other programming languages, the field is omitted from the structure declaration. When an instance of the structure is declared, you must include MQCFBS in a larger structure, and declare additional fields following MQCFBS, to represent the String field as required.
C language declaration
typedef struct tagMQCFBS { MQLONG Type; /* Structure type */ MQLONG StrucLength; /* Structure length */ MQLONG Parameter; /* Parameter identifier */ MQLONG StringLength; /* Length of string */ MQBYTE String[1]; /* String value - first byte */ } MQCFBS;
COBOL language declaration
** MQCFBS structure 10 MQCFBS. ** Structure type 15 MQCFBS-TYPE PIC S9(9) BINARY. ** Structure length 15 MQCFBS-STRUCLENGTH PIC S9(9) BINARY. ** Parameter identifier 15 MQCFBS-PARAMETER PIC S9(9) BINARY. ** Length of string 15 MQCFBS-STRINGLENGTH PIC S9(9) BINARY.
PL/I language declaration ( z/OS® only)
dcl 1 MQCFBS based, 3 Type fixed bin(31), /* Structure type */ 3 StrucLength fixed bin(31), /* Structure length */ 3 Parameter fixed bin(31), /* Parameter identifier */ 3 StringLength fixed bin(31) /* Length of string */
System/390 assembler-language declaration (z/OS only)
MQCFBS DSECT MQCFBS_TYPE DS F Structure type MQCFBS_STRUCLENGTH DS F Structure length MQCFBS_PARAMETER DS F Parameter identifier MQCFBS_STRINGLENGTH DS F Length of string ORG MQCFBS MQCFBS_AREA DS CL(MQCFBS_LENGTH)
Visual Basic language declaration ( Windows only)
Type MQCFBS Type As Long ' Structure type StrucLength As Long ' Structure length Parameter As Long ' Parameter identifier StringLength As Long ' Operator identifier String as 1 ' String value - first byte End Type Global MQCFBS_DEFAULT As MQCFBS
RPG language declaration ( IBM® i only)
D* MQCFBS Structure D* D* Structure type D BSTYP 1 4I 0 INZ(3) D* Structure length D BSLEN 5 8I 0 INZ(16) D* Parameter identifier D BSPRM 9 12I 0 INZ(0) D* Length of string D BSSTL 13 16I 0 INZ(0) D* String value - first byte D BSSRA 17 16 D*