Format of the History Log

A database file is used to store the message sent to a system log. Because all records in a physical file have the same length and messages sent to a log have different lengths, the messages can span more than one record. Each record for a message has three fields:

System date and time (a character field of length 8). This is an internal field. The converted date and time also are in the message.
Record number (a 2-byte field). For example, the field contains hex 0001 for the first record, hex 002 for the second record, and so on.
Data (a character field of length 132).

Format for the third field (data):

Table 1. Format for Third Field of the First Record
Contents	Type	Length	Positions in Record
Job name	Character	26	11-36
Converted date and time	Character	13	37-49
Message ID	Character	7	50-56
Message file name	Character	10	57-66
Library name	Character	10	67-76
Message type	Character	2	77-78
Severity code	Character	2	79-80
Sending program name	Character	12	81-92
Receiving program name	Character	10	97-106
Receiving program instruction number	Character	4	107-110
Message text length	Binary	2	111-112
Message data length	Binary	2	113-114
Reserved	Character	28	115-142

Table 2. Format of the third field (data) of the remaining records
Contents	Type	Length
Message	Character	Variable (This length is specified in the first record (positions 111 and 112) and cannot exceed 132.)
Message data	Character	Variable (This length is specified in the first record (positions 113 and 114).)

A message is never split when a new version of a log is started. The first and last records of a message are always in the same QHST version.

QHST File Processing

If you use a high-level language program to process the QHST file, keep in mind that the message data begins at a variable location for each use of the same message. The reason for this is that the message includes replaceable variables so the actual length of the message varies.

However, for message CPF1124 (job start) and message CPF1165 (job completion) the message data always begins in position 11 of the third record.