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strace(1M)		System Administration Commands		    strace(1M)

       strace -	print STREAMS trace messages

       strace [	mid sid	level...]

       strace  without	arguments writes all STREAMS event trace messages from
       all drivers and modules to its standard output. These messages are  ob-
       tained from the STREAMS log driver (see log(7D)). If arguments are pro-
       vided, 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 indi-
       cating 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 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 : indicates	a fatal	 error
	     N : mail was sent to the system administrator (hardcoded as root)

       <mid> module  ID	number of source

       <sid> sub-ID number of source

	     formatted text of the trace message

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

       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 mod-
       ule  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 attributes(5) for descriptions of the following attributes:

       |      ATTRIBUTE	TYPE	     |	    ATTRIBUTE VALUE	   |
       |Availability		     |SUNWcsu			   |

       attributes(5), log(7D)

       STREAMS Programming Guide

	  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 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	 driv-
	     ers 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.

SunOS 5.9			  4 Oct	1994			    strace(1M)


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