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Chapter 3 131
Command Definitions C-E
CHANGELOG
CHANGELOG
Changes the user logging file without stopping or interrupting the logging process.
Syntax
CHANGELOG logid[ ;DEV=device]
Parameters
logid Name of the currently active user logging process. This name may contain
from one to eight alphanumeric characters, beginning with an alphabetic
character.
device Name of the device on which the new logging file is to be created. The
device may be either DISC or TAPE. Default is DISC.
Operation Notes
This command permits the user to change the active logging file without stopping the
logging process with the LOG logid, STOP command. By specifying a device, you may switch
the logging file from one device to another, regardless of the device on which the logging
file was created. If you enable automatic logging with the ALTLOG or GETLOG command,
however, the only device available for logging is the default, DISC.
If a log file is restricted to a single volume or volume class when it is created with the
BUILD command, then successive log files created by User Logging will have the same
restriction.
If the CHANGELOG command is valid, the system writes a changelog record to the end of the
current logging file and closes the file. It then opens a new logging file whose
characteristics are identical to those of the preceding file and makes the new file
permanent. If the system is unable to open a new file of the same size, it tries to open a
new file half the size of the old file. It repeats this process until a new file is opened
successfully, or until the size is less than 256 records. In the second case, user logging
terminates.
If the system opens a new log file, it immediately writes a changelog record to the new file.
The changelog record posted to the old logging file contains the fully qualified identifier of
the new logging file. A corresponding changelog record written to the new file contains the
fully qualified identifier of the old logging file. Changelog records also contain the device
type of the logging file to which the changelog refers.
The following message is displayed on the $STDLIST to confirm a successful change:
Log file for logid AAA has been changed from
A001.PUB.SYS to A002.PUB.SYS (ulogmsg 38)
If the new logging file is a serial file, a message advising the operator to mount the new log
file appears on the console: