strace(8)strace(8)NAMEstrace - Writes STREAMS event trace messages to standard output
SYNOPSIS
/usr/sbin/strace [mod_ID sub_ID pri_level]
OPERANDS
Specifies the STREAMS module identification number. Specifies a
subidentification number (often corresponding to a minor device).
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 driv‐
ers and modules via the STREAMS log driver (strlog), and writes these
messages to standard output. You can limit the messages strace receives
by specifying 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 mes‐
sages that satisfy the criteria.
STREAMS event trace messages have the following format: seqnum stdtime
tickstime pri_level ntfycode mod_ID sub_ID msgtext
The event trace sequence number. The time the message was sent, in the
format hh:mm:ss. The time the message was sent, measured in machine
ticks since the last boot. The tracing priority level as defined by
the STREAMS driver or module that originates the messages. Can be
either of the following indicators: Indicates that the message has also
been saved in the error log. Indicates that the message signaled a
fatal error. The module identification number of the trace message
source. The subidentification number of the trace message source. 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 messages.
Also be aware that strace may not be able to handle a large number of
messages. If drivers and modules return messages to strace too
quickly, some may be lost.
EXAMPLES
To display all trace messages received from the driver or module iden‐
tified by mod_ID 28, enter: % strace 28 all all 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. 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)strace(8)