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dtruss(1m)                                      USER COMMANDS                                     dtruss(1m)



NAME
       dtruss - process syscall details. Uses DTrace.

SYNOPSIS
       dtruss [-acdeflhoLs] [-t syscall] { -p PID | -n name | command }

DESCRIPTION
       dtruss  prints  details  on  process system calls. It is like a DTrace version of truss, and has been
       designed to be less intrusive than truss.

       Of particular interest is the elapsed times and on cpu times, which can identify  both  system  calls
       that are slow to complete, and those which are consuming CPU cycles.

       Since  this  uses  DTrace,  only the root user or users with the dtrace_kernel privilege can run this
       command.

OPTIONS
       -a     print all details

       -b bufsize
              dynamic variable buffer size. Increase this if you notice dynamic variable  drop  errors.  The
              default is "4m" for 4 megabytes per CPU.

       -c     print system call counts

       -d     print relative timestamps, us

       -e     print elapsed times, us

       -f     follow children as they are forked

       -l     force printing of pid/lwpid per line

       -L     don't print pid/lwpid per line

       -n name
              examine processes with this name

       -o     print on-cpu times, us

       -s     print stack backtraces

       -p PID examine this PID

       -t syscall
              examine this syscall only


EXAMPLES
       run and examine the "df -h" command
              # dtruss df -h


       examine PID 1871
              # dtruss -p 1871


       examine all processes called "tar"
              # dtruss -n tar


       run test.sh and follow children
              # dtruss -f test.sh

       run the "date" command and print elapsed and on cpu times,
              # dtruss -eo date


FIELDS
       PID/LWPID
              Process ID / Lightweight Process ID

       RELATIVE
              relative timestamps to the start of the thread, us (microseconds)

       ELAPSD elapsed time for this system call, us

       CPU    on-cpu time for this system call, us

       SYSCALL(args)
              system call name, with arguments (some may be evaluated)


DOCUMENTATION
       See  the DTraceToolkit for further documentation under the Docs directory. The DTraceToolkit docs may
       include full worked examples with verbose descriptions explaining the output.

EXIT
       dtruss will run forever until Ctrl-C is hit, or if a command was executed dtruss will finish when the
       command ends.

AUTHOR
       Brendan Gregg [Sydney, Australia]

SEE ALSO
       procsystime(1M), dtrace(1M), truss(1)




version 0.80                                    Jun 17, 2005                                      dtruss(1m)