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kdump(1) [opendarwin man page]

KDUMP(1)						    BSD General Commands Manual 						  KDUMP(1)

kdump -- display kernel trace data SYNOPSIS
kdump [-dnlRT] [-f file] [-m maxdata] [-t [cnisuw]] DESCRIPTION
The kdump command displays the kernel trace files produced with ktrace(1) in human readable format. By default, the file ktrace.out in the current directory is displayed. The options are as follows: -d Display all numbers in decimal. -f file Display the specified file instead of ktrace.out. -l Loop reading the trace file, once the end-of-file is reached, waiting for more data. -m maxdata Display at most maxdata bytes when decoding I/O. -n Suppress ad hoc translations. Normally kdump tries to decode many system calls into a more human readable format. For example, ioctl(2) values are replaced with the macro name and errno values are replaced with the strerror(3) string. Suppressing this feature yields a more consistent output format and is easily amenable to further processing. -R Display relative timestamps (time since previous entry). -T Display absolute timestamps for each entry (seconds since epoch). -t cnisuw See the -t option of ktrace(1). SEE ALSO
ktrace(1) HISTORY
The kdump command appeared in 4.4BSD. BSD
June 6, 1993 BSD

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KTRACE(1)						    BSD General Commands Manual 						 KTRACE(1)

ktrace -- enable kernel process tracing SYNOPSIS
ktrace [-aCcdi] [-f trfile] [-g pgrp | -p pid] [-t trstr] ktrace [-adi] [-f trfile] [-t trstr] command DESCRIPTION
The ktrace command enables kernel trace logging for the specified processes. Kernel trace data is logged to the file ktrace.out. 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 either the process exits or the trace point is cleared. A traced process can generate enormous amounts of log data quickly; It is strongly suggested 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: $ ktrace -C The trace file is not human readable; use kdump(1) to decode it. The options are as follows: -a Append to the trace file instead of recreating it. -C Disable tracing on all user owned processes, and, if executed by root, all processes in the system. -c Clear the trace points associated with the specified file or processes. -d Descendants; perform the operation for all current children of the designated processes. -f file Log trace records to file instead of ktrace.out. -g pgid Enable (disable) tracing on all processes in the process group (only one -g flag is permitted). -i Inherit; pass the trace flags to all future children of the designated processes. -p pid Enable (disable) tracing on the indicated process id (only one -p flag is permitted). -t trstr The string argument represents the kernel trace points, one per letter. The following table equates the letters with the trace- points: c trace system calls n trace namei translations i trace I/O s trace signal processing u userland traces w context switches command Execute command with the specified trace flags. The -p, -g, and command options are mutually exclusive. EXAMPLES
# 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 SEE ALSO
kdump(1) BUGS
Only works if file is a regular file. HISTORY
The ktrace command appeared in 4.4BSD. BSD
June 6, 1993 BSD
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