strace(1M) manual page
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strace - print STREAMS trace messages
strace [ mid sid level
] ...
SUNWcsu
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 log(7D)
).
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 (hardcoded as root)
- <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.
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-ID
s 0, 1, or 2:
- strace 41
0 1 41 1 1 41 2 0
Messages from sub-ID
s 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.
log(7D)
- There is no restriction to the number of strace processes opening
the STREAMS
log driver at a time.
- The log-driver records the 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, some of the
messages will be lost. This last case can be determined by examining the
sequence numbers on the trace messages output.
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