kdump(1)

NAME

kdump – display kernel trace data

SYNOPSIS

kdump [-dHlnRTXx] [-f file] [-m maxdata] [-P program] [-p pid] [-t trstr] [-u label]

DESCRIPTION

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.

FILES

ktrace.out

default ktrace dump file

SEE ALSO

ktrace(1)

HISTORY

The kdump command appeared in 4.3BSD-Reno.