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.