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strace(8)							    strace(8)



NAME

  strace - Writes STREAMS event	trace messages to standard output

SYNOPSIS

  /usr/sbin/strace [mod_ID sub_ID pri_level]

OPERANDS

  mod_ID
      Specifies	the STREAMS module identification number.

  sub_ID
      Specifies	a subidentification number (often corresponding	to a minor
      device).

  pri_level
      Specifies	a tracing priority level.  The strace command will get mes-
      sages of a level equal to	or less	than the value in the pri_level	argu-
      ment. The	value of the argument must be a	nonnegative integer.

DESCRIPTION

  The strace command gets STREAMS event	trace messages from STREAMS drivers
  and modules via the STREAMS log driver (strlog), and writes these messages
  to standard output. You can limit the	messages strace	receives by specify-
  ing arguments	to the command.	All three operands must	be specified
  together.

  You can specify all as the value for any of the arguments in the strace
  command line.	The value all indicates	that there are no restrictions for
  that argument.

  You can also specify multiple	sets of	the command's three arguments to
  obtain the messages from more	than one driver	or module.

  More than one	strace process can open	the STREAMS log	driver at a time.
  When you invoke strace, the log driver compares the sets of arguments	from
  the command line with	actual trace messages, returning the messages that
  satisfy the criteria.

  STREAMS event	trace messages have the	following format:

       seqnum  stdtime	tickstime  pri_level  ntfycode	mod_ID	sub_ID	msgtext

  seqnum
      The event	trace sequence number.

  stdtime
      The time the message was sent, in	the format hh:mm:ss.

  tickstime
      The time the message was sent, measured in machine ticks since the last
      boot.

  pri_level
      The tracing priority level as defined by the STREAMS driver or module
      that originates the messages.

  ntfycode
      Can be either of the following indicators:

      E	  Indicates that the message has also been saved in the	error log.

      F	  Indicates that the message signaled a	fatal error.

  mod_ID
      The module identification	number of the trace message source.

  sub_ID
      The subidentification number of the trace	message	source.

  msgtext
      The trace	message	text.

  The strace command runs until	terminated by the user.

RESTRICTIONS

  Running strace with several sets of arguments	can negatively affect STREAMS
  performance, particularly for	those modules and drivers sending the mes-
  sages.

  Also be aware	that strace may	not be able to handle a	large number of	mes-
  sages.  If drivers and modules return	messages to strace too quickly,	some
  may be lost.

EXAMPLES

   1.  To display all trace messages received from the driver or module	iden-
       tified by mod_ID	28, enter:
	    % strace 28	all all

   2.  To display those	trace messages from the	driver or module identified
       by mod_ID 28 and	its minor devices identified by	the sub_IDs 2, 3, and
       4, enter:
	    % strace  28 2 all	28 3 all  28 4 all

       This command line causes	messages of any	tracing	priority level to be
       displayed.

   3.  To display the trace messages from the same driver or module and
       sub_IDs,	but limited to certain priority	levels,	enter:
	    % strace  28 2 0  28 3 0  28 4 1

       This command line specifies that	messages from driver or	module 28 and
       sub_IDs 2 and 3 must have a tracing priority of 0, and those from
       sub_ID 4	must have a tracing priority equal to or less than 1.

SEE ALSO

  Commands: strclean(8), strerr(8)

  Interfaces: strlog(7)