kdump — display
kernel trace data
kdump |
[-dHlnRTXx] [-f
file] [-m
maxdata] [-P
program] [-p
pid] [-t
trstr] [-u
label] |
kdump 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, unless overridden by the -f
option.
The options are as follows:
-d- Display all numbers in decimal. By default, values are printed out in
hexadecimal.
-f
file- Display the specified file instead of ktrace.out.
Specifying ‘-’ will read from standard input.
-H- Display thread identifiers.
-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.
-P
program- Show output only for processes with program as their
command name.
-p
pid- Show output only for the pid specified.
-R- Display relative timestamps (time since previous entry).
-T- Display absolute timestamps for each entry (seconds since the Epoch).
-TR- If both options are specified, display timestamps relative to trace
start.
-t
trstr- Select which tracepoints to display. The argument can contain one or more
of the following letters. By default all trace points except for
X are enabled.
c- trace system calls
i- trace I/O
n- trace namei translations
p- trace violation of pledge(2) restrictions
s- trace signal processing
S- trace violation of pinsyscalls(2)
t- trace various structures
u- trace user data coming from utrace(2)
x- trace argument vector in execve(2)
X- trace environment in execve(2)
+- trace the default points
-u
label- Display utrace(2) tracepoints having
utrace(2) label label as strings
with vis(3) escaping, without
ktrace(2) header information.
-X- Display I/O data with hexadecimal data and printable ASCII characters side
by side.
-x- Display I/O data in hexadecimal.
The -t and -u
options are mutually exclusive; the last one specified overrides any
previous ones.
- ktrace.out
- default ktrace dump file
The kdump command appeared in
4.3BSD-Reno.