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:

     <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 adminis-
           trator (hardcoded as root)

     <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  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.

ATTRIBUTES

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

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWcsu                     |
    |_____________________________|_____________________________|

SEE ALSO

     attributes(5), log(7D)

     STREAMS Programming Guide

NOTES

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

        o  The log-driver records the list of the triplets speci-
           fied  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 pro-
           cess. 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 han-
           dle them,  some of the messages  will  be  lost.  This
           last  case can be determined by examining the sequence
           numbers on the trace messages output.