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Type (MQLONG)

Structure type.

This indicates that the structure is an MQCFSL structure describing a string-list parameter. The value must be:

MQCFT_STRING_LIST

Structure defining a string list.

StrucLength (MQLONG)

Structure length.

This is the length in bytes of the MQCFSL structure, including the data at the end of the structure (the Strings field). The length must be a multiple of four, and must be sufficient to contain all of the strings; any bytes between the end of the strings 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 Strings field:

MQCFSL_STRUC_LENGTH_FIXED

Length of fixed part of command format string-list parameter structure.

Parameter (MQLONG)

Parameter identifier.

This identifies the parameter whose values are 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.

The parameter is from the following groups of parameters:

  • MQCA_*

  • MQCACF_*

  • MQCAMO_*

  • MQCACH_*

CodedCharSetId (MQLONG)

Coded character set identifier.

This specifies the coded character set identifier of the data in the Strings field. The following special value can be used:

MQCCSI_DEFAULT

Default character set identifier.

The string data is in the character set defined by the CodedCharSetId field in the MQ header structure that precedes the MQCFH structure, or by the CodedCharSetId field in the MQMD if the MQCFH structure is at the start of the message.

Count (MQLONG)

Count of parameter values.

This is the number of strings present in the Strings field; it must be zero or greater.

StringLength (MQLONG)

Length of one string.

This is the length in bytes of one parameter value, that is the length of one string in the Strings field; all of the strings are this length. The length must be zero or greater, and need not be a multiple of four.

Strings (MQCHAR×StringLength×Count)

String values.

This is a set of string values for the parameter identified by the Parameter field. The number of strings is given by the Count field, and the length of each string is given by the StringLength field. The strings are concatenated together, with no bytes skipped between adjacent strings. The total length of the strings is the length of one string multiplied by the number of strings present (that is, StringLength×Count).

  • In MQFMT_ADMIN command messages, if the specified string is shorter than the standard length of the parameter, the omitted characters are assumed to be blanks. If the specified string is longer than the standard length, it is an error.

  • In MQFMT_ADMIN response messages, string parameters may be returned padded with blanks to the standard length of the parameter.

  • In MQFMT_EVENT messages, trailing blanks may be omitted from string parameters (that is, the string may be shorter than the standard length of the parameter).

In all cases, StringLength gives the length of the string actually present in the message.

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

When the queue manager reads an MQCFSL structure in an MQFMT_ADMIN message from the command input queue, the queue manager processes each string in the list as though it had been specified on an MQI call. This means that within each string, the first null and the characters following it (up to the end of the string) are treated as blanks.

In responses and all other cases, a null character in a string is treated as normal data, and does not act as a delimiter for the string. This means that when a receiving application reads a MQFMT_PCF, MQFMT_EVENT, or MQFMT_ADMIN message, the receiving application receives all of the data specified by the sending application.

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 the COBOL, PL/I, RPG, and System/390 assembler programming languages, the field is omitted from the structure declaration. When an instance of the structure is declared, include MQCFSL in a larger structure, and declare additional fields following MQCFSL, to represent the Strings field as required.

 

Parent topic:

MQCFSL - PCF string list parameter


pc15240_


 

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