File I/O trace

The file I/O trace is an EBCDIC encoded trace that can be used as a debugging aid for file I/O failures. The files that are traced, the level of detail provided by the trace, and the trace table size can be controlled with the environment variable _EDC_IO_TRACE. For more information about _EDC_IO_TRACE, see _EDC_IO_TRACE. Figure 1 shows the result of running a file I/O application with the displayed environment variable setting.
Figure 1. Sample File I/O Trace
EDCTRACE   File I/O Trace   z/OS XL C/C++ Release: 410B0000   09/28/08 09:14:43 AM

Trace details for /u/bryntco/hle7760/B49300/ut/tst/myfile.dat:

        Trace detail level:  2
        Trace buffer size:   2048K

        fopen(/u/bryntco/hle7760/B49300/ut/tst/myfile.dat,w)

        fldata:
            __recfmF:1........ 0            __dsorgVSAM:1..... 0
            __recfmV:1........ 0            __dsorgHFS:1...... 1
            __recfmU:1........ 1            __openmode:2...... 1
            __recfmS:1........ 0            __modeflag:4...... 2
            __recfmBlk:1...... 0            __dsorgPDSE:1..... 0
            __recfmASA:1...... 0            __reserve2:4...... 0
            __recfmM:1........ 0            __device.......... 9
            __dsorgPO:1....... 0            __blksize......... 0
            __dsorgPDSmem:1... 0            __maxreclen....... 0
            __dsorgPDSdir:1... 0            __vsamtype........ 0
            __dsorgPS:1....... 0            __vsamkeylen...... 0
            __dsorgConcat:1... 0            __vsamRKP......... 0
            __dsorgMem:1...... 0            __access_method... 0 (0)
            __dsorgHiper:1.... 0            __noseek_to_seek.. 0 (0)
            __dsorgTemp:1..... 0

            FILE pointer...... 21A34030

        Trace Entries:
            Function Name                   Trace Type
              openhfs                         Entry
              fwrite                          Entry
              mwphfs                          Entry
              wp124                           Entry
              __pcloseall                     Entry
              cp124                           Entry