strace(1M)                                                       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 [see 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 mes-
     sages 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

     text      formatted text of the trace message

     Once initiated, strace will continue to execute until terminated by
     the user.











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strace(1M)                                                       strace(1M)

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.

NOTES
     Due to performance considerations, only one strace process is permit-
     ted 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 pro-
     cess 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).

     Programmer's Guide: STREAMS






















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