strace(ADM)
strace --
print STREAMS trace messages
Syntax
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(M)).
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
where:
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
text-
formatted text of the trace message
Once initiated, strace will continue to execute until
terminated by the user.
Diagnostics
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.
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.
See also
log(M)
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003