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 obtained from the STREAMS log driver (see
If arguments are provided 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
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>
trace sequence number
time of message in hh:mm:ss
time of message in machine ticks since boot
tracing priority level
message is also in the error log
indicates a fatal error
mail was sent to the system administrator
number of source
sub-ID number of source
formatted text of the trace message
Once initiated, strace will continue to execute
until terminated by the user.
Due to performance considerations,
only one strace process is permitted
to open the STREAMS log driver at a time.
The log driver has a 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 drivers generating the trace messages that are sent
to the strace process.
If trace messages are generated faster than the strace
process can handle them, then some of the messages will be lost.
This last case can be determined by examining the sequence numbers
on the trace messages output.
Output all trace messages from the module or driver whose module
ID is 41:
strace 41 all all
Output those trace messages from driver/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.
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004