LU 6.2 API Application Programmer's Reference Guide (30294-90008)

138 Chapter7
Debugging
The User Trace
Collecting the User Trace
The user trace file is created in the group and account from which the
TP is run. The default name is PSTRAC
nn , where nn is a number from
00 through 49 that increments each time a new file is opened.
After 25 user trace files are created, the system purges one trace file
each time a new one is opened. Trace files are created and numbered as
follows:
1. Trace files PSTRAC00 through PSTRAC24 are created.
2. PSTRAC25 is created and file PSTRAC00 is purged.
3. The next trace file created is PSTRAC26. When PSTRAC26 is created,
PSTRAC01 is purged.
4. When PSTRAC27 is created, PSTRAC02 is purged, and so on.
5. After trace file PSTRAC49 is created, the numbering wraps and the
next file created is PSTRAC00.
There are never more than twenty-five trace files in the group and
account where the TP is running, because, after the twenty-fifth file is
created, an old file is purged for each new one created. Because the
numbering wraps to 00 after it reaches 49, the youngest trace file could
be numbered either low or high. The key to finding the youngest file is
determining whether the file numbers have wrapped.
If the file numbers have not wrapped, the numbering will be
contiguous; that is, no gaps will exist between numbers. In the
following example, PSTRAC00 to PSTRAC21 have been purged, and
PSTRAC47 to PSTRAC49 do not exist. Therefore, the files have not
wrapped, and the file with the highest number is the youngest.