strace(1M)                     DG/UX R4.11MU05                    strace(1M)


NAME
       strace - print STREAMS trace messages

SYNOPSIS
       strace [ mid sid level ] ...

DESCRIPTION
       Strace without arguments writes all STREAMS event trace messages from
       all drivers and modules to its standard output.  These messages are
       obtained from the STREAMS log driver (log(7)).  If arguments are
       provided, they must be in triplets of the form mid, sid, level, where
       mid is a STREAMS module id number, sid is a sub-id number, and level
       is a tracing priority level.  Each triplet indicates that tracing
       messages are to be received from the given module/driver, sub-id
       (usually indicating minor device), and priority level equal to or
       less than the given level.  The token all may be used for any member
       to indicate no restriction for that attribute.

       The format of each trace message output is:

       seq time ticks level flags mid sid text

       seq       trace sequence number

       time      time of message in hh:mm:ss

       ticks     time of message in machine ticks since boot

       level     tracing priority level

       flags     E : message is also in the error log
                 F : indicates a fatal error
                 N : mail was sent to the system administrator

       mid       module id number of source

       sid       sub-id number of source

       text      formatted text of the trace message

       Once initiated, strace will continue to execute until terminated by
       the user.

EXAMPLES
       Output all trace messages from the module or driver whose module id
       is 41:

              strace  41 all all

       Output those trace messages from driver/module id 41 with sub-ids 0,
       1, or 2:

              strace  41 0 1  41 1 1  41 2 0

       Messages from sub-ids 0 and 1 must have a tracing level less than or
       equal to 1.  Those from sub-id 2 must have a tracing level of 0.

SEE ALSO
       strerr(1M), log(7).
       STREAMS Programmer's Guide for the DG/UX System.

NOTES
       Due to performance considerations, only one strace process is
       permitted to open the STREAMS log driver at a time.  The log driver
       has a list of the triplets specified in the command invocation, and
       compares each potential trace message against this list to decide if
       it should be formatted and sent up to the strace process.  Hence,
       long lists of triplets will have a greater impact on overall STREAMS
       performance.  Running strace will have the most impact on the timing
       of the modules and drivers generating the trace messages that are
       sent to the strace process.  If trace messages are generated faster
       than the strace process can handle them, some of the messages will be
       lost.  This last case can be determined by examining the sequence
       numbers on the trace messages output.


Licensed material--property of copyright holder(s)