System Administration Commands                         strace(1M)



NAME
     strace - print STREAMS trace messages

SYNOPSIS
     strace [mid sid level]...


DESCRIPTION
     strace without arguments writes all STREAMS event trace mes-
     sages  from  all drivers and modules to its standard output.
     These messages are obtained from the STREAMS log driver (see
     log(7D)).  If  arguments  are provided, they must be in tri-
     plets 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:


            

           trace sequence number


          time of message in hh:mm:ss


         time of message in machine ticks since boot


         tracing priority level


         E : message is also in the error log  F  :  indi-
                cates a fatal error N : mail was sent to the sys-
                tem administrator (hardcoded as root)


           module  ID number of source


           sub-ID number of source


          formatted text of the trace message




SunOS 5.11           Last change: 4 Oct 1994                    1






System Administration Commands                         strace(1M)



     Once initiated, strace will continue to execute  until  ter-
     minated by the user.

EXAMPLES
     Example 1 A sample output of the strace command:


     The following example outputs all trace  messages  from  the
     module or driver whose module  ID is  41:


       strace  41 all all




     The following example  outputs  those  trace  messages  from
     driver or 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.


ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Availability                 SUNWcsu                     
    


SEE ALSO
     attributes(5), log(7D)


NOTES
         o    There is no restriction to  the  number  of  strace
              processes  opening  the   STREAMS  log  driver at a
              time.




SunOS 5.11           Last change: 4 Oct 1994                    2






System Administration Commands                         strace(1M)



         o    The log-driver records the  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 perfor-
              mance. 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 pro-
              cess.  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 deter-
              mined by examining  the  sequence  numbers  on  the
              trace messages output.









































SunOS 5.11           Last change: 4 Oct 1994                    3