'\" t
.\"     Title: lttng-crash
.\"    Author: [FIXME: author] [see http://www.docbook.org/tdg5/en/html/author]
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 2 April 2020
.\"    Manual: LTTng Manual
.\"    Source: LTTng 2.12.3
.\"  Language: English
.\"
.TH "LTTNG\-CRASH" "1" "2 April 2020" "LTTng 2\&.12\&.3" "LTTng Manual"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
lttng-crash \- Recover and view LTTng 2 trace buffers in the event of a crash
.SH "SYNOPSIS"
.sp
.nf
\fBlttng\-crash\fR [\fB--extract\fR=\fIPATH\fR | \fB--viewer\fR=\fIVIEWER\fR] [\fB-v\fR | \fB-vv\fR | \fB-vvv\fR] \fISHMDIR\fR
.fi
.SH "DESCRIPTION"
.sp
The \fILinux Trace Toolkit: next generation\fR <https://lttng.org/> is an open source software package used for correlated tracing of the Linux kernel, user applications, and user libraries\&.
.sp
LTTng consists of Linux kernel modules (for Linux kernel tracing) and dynamically loaded libraries (for user application and library tracing)\&.
.sp
The \fBlttng-crash\fR command\-line tool is used to recover and view LTTng trace buffers in the event of a system crash\&.
.sp
\fBlttng-crash\fR reads files within the directory \fISHMDIR\fR and does one of:
.PP
Without the \fB--extract\fR option
.RS 4
Launches a trace reader (see the
\fB--viewer\fR
option) to view the recovered traces\&.
.RE
.PP
With the \fB--extract\fR option
.RS 4
Extracts them as uncorrupted LTTng traces on the file system\&.
.RE
.sp
\fISHMDIR\fR is the directory specified as the argument of the \fB--shm-path\fR option of the \fBlttng-create\fR(1) command used to create the tracing session for which to recover the traces\&.
.SH "OPTIONS"
.PP
\fB-x\fR \fIPATH\fR, \fB--extract\fR=\fIPATH\fR
.RS 4
Extract recovered traces to path
\fIPATH\fR; do not execute the trace viewer\&.
.RE
.PP
\fB-v\fR, \fB--verbose\fR
.RS 4
Increase verbosity\&.
.sp
Three levels of verbosity are available, which are triggered by appending additional
\fBv\fR
letters to the option (that is,
\fB-vv\fR
and
\fB-vvv\fR)\&.
.RE
.PP
\fB-e\fR \fIVIEWER\fR, \fB--viewer\fR=\fIVIEWER\fR
.RS 4
Use trace viewer
\fIVIEWER\fR
to view the trace buffers\&.
\fIVIEWER\fR
is the absolute path to the viewer command to use, and it can contain command arguments as well\&. The trace directory paths are passed to the
\fIVIEWER\fR
command as its last arguments\&.
.sp
Without this option,
\fBlttng crash\fR
uses
\fBbabeltrace2\fR(1)
if it\(cqs available\&. Otherwise, it tries to use
\fBbabeltrace\fR(1)\&.
.RE
.SS "Program information"
.PP
\fB-h\fR, \fB--help\fR
.RS 4
Show help\&.
.RE
.PP
\fB-V\fR, \fB--version\fR
.RS 4
Show version\&.
.RE
.SH "EXIT STATUS"
.PP
\fB0\fR
.RS 4
Success
.RE
.PP
\fB1\fR
.RS 4
Error
.RE
.PP
\fB3\fR
.RS 4
Fatal error
.RE
.SH "BUGS"
.sp
If you encounter any issue or usability problem, please report it on the LTTng bug tracker <https://bugs.lttng.org/projects/lttng-tools>\&.
.SH "RESOURCES"
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
LTTng project website <https://lttng.org>
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
LTTng documentation <https://lttng.org/docs>
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Git repositories <http://git.lttng.org>
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
GitHub organization <http://github.com/lttng>
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Continuous integration <http://ci.lttng.org/>
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Mailing list <http://lists.lttng.org>
for support and development:
\fBlttng-dev@lists.lttng.org\fR
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
IRC channel <irc://irc.oftc.net/lttng>:
\fB#lttng\fR
on
\fBirc.oftc.net\fR
.RE
.SH "COPYRIGHTS"
.sp
This program is part of the LTTng\-tools project\&.
.sp
LTTng\-tools is distributed under the GNU General Public License version 2 <http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html>\&. See the \fBLICENSE\fR <https://github.com/lttng/lttng-tools/blob/master/LICENSE> file for details\&.
.SH "THANKS"
.sp
Special thanks to Michel Dagenais and the DORSAL laboratory <http://www.dorsal.polymtl.ca/> at \('Ecole Polytechnique de Montr\('eal for the LTTng journey\&.
.sp
Also thanks to the Ericsson teams working on tracing which helped us greatly with detailed bug reports and unusual test cases\&.
.SH "SEE ALSO"
.sp
\fBlttng\fR(1), \fBlttng-sessiond\fR(8), \fBlttng-relayd\fR(8), \fBlttng-ust\fR(3), \fBbabeltrace2\fR(1)