OSF

NAME

strace − Writes STREAMS event trace messages

SYNOPSIS

/usr/sbin/strace [mod_ID sub_ID priority_level]

PARAMETERS

The strace daemon may be specified without parameters; however, if specifying parameters, no parameter fields are optional.  Instead, specify all to indicate that there is no restriction for a particular parameter field.  The parameters are as follows:

mod_IDSpecifies the STREAMS module identification number. 

sub_IDSpecifies a subidentification number (often corresponding to a minor device). 

priority_levelSpecifies a tracing priority level.  The strace daemon will get messages of a level equal to or less than the value in the priority_level argument.  The value of the argument must be a nonnegative integer. 

allSpecifies that a parameter field (mod_ID, sub_ID, or priority_ID) has no restrictions. 

DESCRIPTION

The strace daemon retrieves STREAMS event trace messages from the STREAMS log driver, strlog, and writes the information to standard output.  When specified without parameters, STREAMS event trace messages from all STREAMS drivers are written to standard output.  When specified with parameters, you can obtain event tracing from one or more STREAMS driver or module by specifying multiple sets of parameters. 

The STREAMS log driver, strlog may be opened by only one strace process at a  time.  The log driver compares the parameters specified with actual trace messages and returns the messages that satisfy the criteria.  See the NOTES section for more information. 

A STREAMS event trace message has the following format:

sequence_num  std_time  ticks_time  priority_level  notify_code  mod_ID  sub_ID  mesg_text

where:

sequence_num
The event trace sequence number.

std_timeThe time the message was sent, in the format hh:mm:ss. 

ticks_timeThe time the message was sent, measured in machine ticks since the last boot. 

priority_levelThe tracing priority level. 

notify_codeCan be either of the following indicators:

EIndicates that the message has also been saved in the error log. 

FIndicates that the message signaled a fatal error. 

mod_IDThe module identification number of the trace message source. 

sub_IDThe subidentification number of the trace message source. 

mesg_textThe trace message text. 

The strace daemon runs until terminated by the user. 

EXAMPLES

The following examples show how to use the strace daemon. 

     1.To display all trace messages received from the driver or module identified by mod_ID 28, enter:

# strace 28 all all

     2.To display those trace messages from the driver or module identified by mod_ID 28 and its minor devices identified by the sub_IDs 2, 3, and 4, enter:

# strace  28 2 all  28 3 all  28 4 all

This command line causes messages of any tracing priority level to be displayed.

     3.To display the trace messages from the same driver or module and sub-IDs, but limited to certain priority levels, enter:

# strace  28 2 0  28 3 0  28 4 1

This command line specifies that messages from driver or module 28 and sub-IDs 2 and 3 must have a tracing priority of 0 and those from sub-ID 4 must have a tracing priority equal to or less than 1. 

NOTES

Running strace with several sets of parameters can degrade performance, as the strlog interface must interpret each set of parameters to determine if trace event information should be sent to the strace process.  Likewise, strace messages are generated more quickly than the strace process can handle them, some messages may be lost. 

FILES

/usr/sbin/straceSpecifies the command path. 

RELATED INFORMATION

Commands:  strclean(8), strerr(8)

Interfaces: strlog(7)