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KTRACE(1)                    BSD Reference Manual                    KTRACE(1)

N\bNA\bAM\bME\bE
     k\bkt\btr\bra\bac\bce\be - enable kernel process tracing

S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
     k\bkt\btr\bra\bac\bce\be [-\b-a\baC\bCc\bcd\bdi\bi] [-\b-f\bf _\bt_\br_\bf_\bi_\bl_\be] [-\b-g\bg _\bp_\bg_\br_\bp] [-\b-p\bp _\bp_\bi_\bd] [-\b-t\bt _\bt_\br_\bs_\bt_\br]
     k\bkt\btr\bra\bac\bce\be [-\b-a\bad\bdi\bi] [-\b-f\bf _\bt_\br_\bf_\bi_\bl_\be] [-\b-t\bt _\bt_\br_\bs_\bt_\br] command

D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
     K\bKt\btr\bra\bac\bce\be enables kernel trace logging for the specified processes.  Kernel
     trace data is logged to the file _\bk_\bt_\br_\ba_\bc_\be_\b._\bo_\bu_\bt. The kernel operations that
     are traced include system calls, namei translations, signal processing,
     and I/O.

     Once tracing is enabled on a process, trace data will be logged until ei-
     ther the process exits or the trace point is cleared.  A traced process
     can generate enormous amounts of log data quickly; It is strongly sug-
     gested that users memorize how to disable tracing before attempting to
     trace a process.  The following command is sufficient to disable tracing
     on all user owned processes, and, if executed by root, all processes:

           $ trace -C

     The trace file is not human readable; use kdump(1) to decode it.

     The options are as follows:

     -\b-a\ba      Append to the trace file instead of truncating it.

     -\b-C\bC      Disable tracing on all user owned processes, and, if executed by
             root, all processes in the system.

     -\b-c\bc      Clear the trace points associated with the specified file or pro-
             cesses.

     -\b-d\bd      Descendants; perform the operation for all current children of
             the designated processes.

     -\b-f\bf _\bf_\bi_\bl_\be
             Log trace records to _\bf_\bi_\bl_\be instead of _\bk_\bt_\br_\ba_\bc_\be_\b._\bo_\bu_\bt.

     -\b-g\bg _\bp_\bg_\bi_\bd
             Enable (disable) tracing on all processes in the process group
             (only one -\b-g\bg flag is permitted).

     -\b-i\bi      Inherit; pass the trace flags to all future children of the des-
             ignated processes.

     -\b-p\bp _\bp_\bi_\bd  Enable (disable) tracing on the indicated process id (only one -\b-p\bp
             flag is permitted).

     -\b-t\bt _\bt_\br_\bs_\bt_\br
             The string argument represents the kernel trace points, one per
             letter.  The following table equates the letters with the trace-
             points:

             c\bc     trace system calls
             n\bn     trace namei translations
             i\bi     trace I/O
             s\bs     trace signal processing

     _\bc_\bo_\bm_\bm_\ba_\bn_\bd
             Execute _\bc_\bo_\bm_\bm_\ba_\bn_\bd with the specified trace flags.


     The -\b-p\bp, -\b-g\bg, and _\bc_\bo_\bm_\bm_\ba_\bn_\bd options are mutually exclusive.

E\bEX\bXA\bAM\bMP\bPL\bLE\bES\bS
     # trace all kernel operations of process id 34
           $ ktrace -p 34

     # trace all kernel operations of processes in process group 15 and # pass
     the trace flags to all current and future children
           $ ktrace -idg 15

     # disable all tracing of process 65
           $ ktrace -cp 65

     # disable tracing signals on process 70 and all current children
           $ ktrace -t s -cdp 70

     # enable tracing of I/O on process 67
           $ ktrace -ti -p 67

     # run the command "w", tracing only system calls
           $ ktrace -tc w

     # disable all tracing to the file "tracedata"
           $ ktrace -c -f tracedata

     # disable tracing of all processes owned by the user
           $ ktrace -C

S\bSE\bEE\bE A\bAL\bLS\bSO\bO
     kdump(1)

H\bHI\bIS\bST\bTO\bOR\bRY\bY
     The k\bkt\btr\bra\bac\bce\be command appears in 4.4BSD.

4.4BSD                           June 6, 1993                                2