STRACE(1M) (Networking Support Utilities) STRACE(1M)
NAME
strace - print STREAMS trace messages
SYNOPSIS
strace [ mid sid level ] ...
DESCRIPTION
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 [log(7)]. 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 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 administrator
<mid> module id number of source
<sid> sub-id number of source
Page 1 May 1989
STRACE(1M) (Networking Support Utilities) STRACE(1M)
<text> formatted text of the trace message
Once initiated, strace will continue to execute until
terminated by the user.
EXAMPLES
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.
CAVEATS
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.
SEE ALSO
log(7).
STREAMS Programmer's Guide.
Page 2 May 1989