NAME

       lttng-view - Launch an LTTng trace reader

SYNOPSIS

       lttng [GENERAL OPTIONS] view [--viewer=READER]
             [SESSION | --trace-path=DIR]

DESCRIPTION

       The lttng view command launches an external trace reader to read the current traces of:

       With the --session=SESSION option
           The recording session named SESSION.

       With the --trace-path=DIR option
           The local file system directory DIR.

       Otherwise
           The current recording session (see concepts(1) to learn more about the current
           recording session).

       With the --session option or without the --trace-path option, the mode of the selected
       recording session may NOT be network streaming or live.

       By default, the view command attempts to launch babeltrace2(1) or, if it’s not available,
       babeltrace(1). Override which trace reader to launch with the --viewer option.

       See the “EXAMPLES” section below for usage examples.

OPTIONS

       See lttng(1) for GENERAL OPTIONS.

       -t DIR, --trace-path=DIR
           Pass DIR as the last argument of the trace reader command instead of the output
           directory of the selected recording session.

       -e READER, --viewer=READER
           Use the trace reader READER to read the traces.

           READER is the absolute path to the reader command to use, and it can contain command
           arguments as well. The view command passes the trace directory path to read to the
           READER command as its last argument.

           Without this option, the view command uses babeltrace2(1) if it’s available.
           Otherwise, it tries to use babeltrace(1).

   Program information
       -h, --help
           Show help.

           This option attempts to launch /usr/bin/man to view this manual page. Override the
           manual pager path with the LTTNG_MAN_BIN_PATH environment variable.

       --list-options
           List available command options and quit.

EXIT STATUS

       0
           Success

       1
           Command error

       2
           Undefined command

       3
           Fatal error

       4
           Command warning (something went wrong during the command)

ENVIRONMENT

       LTTNG_ABORT_ON_ERROR
           Set to 1 to abort the process after the first error is encountered.

       LTTNG_HOME
           Path to the LTTng home directory.

           Defaults to $HOME.

           Useful when the Unix user running the commands has a non-writable home directory.

       LTTNG_MAN_BIN_PATH
           Absolute path to the manual pager to use to read the LTTng command-line help (with
           lttng-help(1) or with the --help option) instead of /usr/bin/man.

       LTTNG_SESSION_CONFIG_XSD_PATH
           Path to the directory containing the session.xsd recording session configuration XML
           schema.

       LTTNG_SESSIOND_PATH
           Absolute path to the LTTng session daemon binary (see lttng-sessiond(8)) to spawn from
           the lttng-create(1) command.

           The --sessiond-path general option overrides this environment variable.

FILES

       $LTTNG_HOME/.lttngrc
           Unix user’s LTTng runtime configuration.

           This is where LTTng stores the name of the Unix user’s current recording session
           between executions of lttng(1).  lttng-create(1) and lttng-set-session(1) set the
           current recording session.

       $LTTNG_HOME/lttng-traces
           Default output directory of LTTng traces in local and snapshot modes.

           Override this path with the --output option of the lttng-create(1) command.

       $LTTNG_HOME/.lttng
           Unix user’s LTTng runtime and configuration directory.

       $LTTNG_HOME/.lttng/sessions
           Default directory containing the Unix user’s saved recording session configurations
           (see lttng-save(1) and lttng-load(1)).

       /etc/lttng/sessions
           Directory containing the system-wide saved recording session configurations (see
           lttng-save(1) and lttng-load(1)).

       Note
           $LTTNG_HOME defaults to the value of the HOME environment variable.

EXAMPLES

       Example 1. Read the traces of the current recording session with Babeltrace.

               $ lttng view

       Example 2. Read the traces of a specific recording session with a custom trace reader.

           See the --viewer option.

               $ lttng view --viewer='/usr/bin/my-reader -zK --details=3' \
                            my-session

RESOURCES

       •   LTTng project website <https://lttng.org>

       •   LTTng documentation <https://lttng.org/docs>

       •   LTTng bug tracker <https://bugs.lttng.org>

       •   Git repositories <https://git.lttng.org>

       •   GitHub organization <https://github.com/lttng>

       •   Continuous integration <https://ci.lttng.org/>

       •   Mailing list <https://lists.lttng.org/> for support and development: lttng-
           dev@lists.lttng.org

       •   IRC channel <irc://irc.oftc.net/lttng>: #lttng on irc.oftc.net

COPYRIGHT

       This program is part of the LTTng-tools project.

       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 LICENSE
       <https://github.com/lttng/lttng-tools/blob/master/LICENSE> file for details.

THANKS

       Special thanks to Michel Dagenais and the DORSAL laboratory
       <http://www.dorsal.polymtl.ca/> at École Polytechnique de Montréal for the LTTng journey.

       Also thanks to the Ericsson teams working on tracing which helped us greatly with detailed
       bug reports and unusual test cases.

SEE ALSO

       babeltrace2(1), lttng(1)