1LTTNG-VIEW(1)                    LTTng Manual                    LTTNG-VIEW(1)
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NAME

6       lttng-view - Launch an LTTng trace reader
7

SYNOPSIS

9       lttng [GENERAL OPTIONS] view [--viewer=READER]
10             [SESSION | --trace-path=DIR]
11

DESCRIPTION

13       The lttng view command launches an external trace reader to read the
14       current traces of:
15
16       With the --session=SESSION option
17           The recording session named SESSION.
18
19       With the --trace-path=DIR option
20           The local file system directory DIR.
21
22       Otherwise
23           The current recording session (see concepts(1) to learn more about
24           the current recording session).
25
26       With the --session option or without the --trace-path option, the mode
27       of the selected recording session may NOT be network streaming or live.
28
29       By default, the view command attempts to launch babeltrace2(1) or, if
30       it’s not available, babeltrace(1). Override which trace reader to
31       launch with the --viewer option.
32
33       See the “EXAMPLES” section below for usage examples.
34

OPTIONS

36       See lttng(1) for GENERAL OPTIONS.
37
38       -t DIR, --trace-path=DIR
39           Pass DIR as the last argument of the trace reader command instead
40           of the output directory of the selected recording session.
41
42       -e READER, --viewer=READER
43           Use the trace reader READER to read the traces.
44
45           READER is the absolute path to the reader command to use, and it
46           can contain command arguments as well. The view command passes the
47           trace directory path to read to the READER command as its last
48           argument.
49
50           Without this option, the view command uses babeltrace2(1) if it’s
51           available. Otherwise, it tries to use babeltrace(1).
52
53   Program information
54       -h, --help
55           Show help.
56
57           This option attempts to launch /usr/bin/man to view this manual
58           page. Override the manual pager path with the LTTNG_MAN_BIN_PATH
59           environment variable.
60
61       --list-options
62           List available command options and quit.
63

EXIT STATUS

65       0
66           Success
67
68       1
69           Command error
70
71       2
72           Undefined command
73
74       3
75           Fatal error
76
77       4
78           Command warning (something went wrong during the command)
79

ENVIRONMENT

81       LTTNG_ABORT_ON_ERROR
82           Set to 1 to abort the process after the first error is encountered.
83
84       LTTNG_HOME
85           Path to the LTTng home directory.
86
87           Defaults to $HOME.
88
89           Useful when the Unix user running the commands has a non-writable
90           home directory.
91
92       LTTNG_MAN_BIN_PATH
93           Absolute path to the manual pager to use to read the LTTng
94           command-line help (with lttng-help(1) or with the --help option)
95           instead of /usr/bin/man.
96
97       LTTNG_SESSION_CONFIG_XSD_PATH
98           Path to the directory containing the session.xsd recording session
99           configuration XML schema.
100
101       LTTNG_SESSIOND_PATH
102           Absolute path to the LTTng session daemon binary (see lttng-
103           sessiond(8)) to spawn from the lttng-create(1) command.
104
105           The --sessiond-path general option overrides this environment
106           variable.
107

FILES

109       $LTTNG_HOME/.lttngrc
110           Unix user’s LTTng runtime configuration.
111
112           This is where LTTng stores the name of the Unix user’s current
113           recording session between executions of lttng(1).  lttng-create(1)
114           and lttng-set-session(1) set the current recording session.
115
116       $LTTNG_HOME/lttng-traces
117           Default output directory of LTTng traces in local and snapshot
118           modes.
119
120           Override this path with the --output option of the lttng-create(1)
121           command.
122
123       $LTTNG_HOME/.lttng
124           Unix user’s LTTng runtime and configuration directory.
125
126       $LTTNG_HOME/.lttng/sessions
127           Default directory containing the Unix user’s saved recording
128           session configurations (see lttng-save(1) and lttng-load(1)).
129
130       /usr/local/etc/lttng/sessions
131           Directory containing the system-wide saved recording session
132           configurations (see lttng-save(1) and lttng-load(1)).
133
134       Note
135           $LTTNG_HOME defaults to the value of the HOME environment variable.
136

EXAMPLES

138       Example 1. Read the traces of the current recording session with
139       Babeltrace.
140
141               $ lttng view
142
143       Example 2. Read the traces of a specific recording session with a
144       custom trace reader.
145
146           See the --viewer option.
147
148               $ lttng view --viewer='/usr/bin/my-reader -zK --details=3' \
149                            my-session
150

RESOURCES

152       •   LTTng project website <https://lttng.org>
153
154       •   LTTng documentation <https://lttng.org/docs>
155
156       •   LTTng bug tracker <https://bugs.lttng.org>
157
158       •   Git repositories <https://git.lttng.org>
159
160       •   GitHub organization <https://github.com/lttng>
161
162       •   Continuous integration <https://ci.lttng.org/>
163
164       •   Mailing list <https://lists.lttng.org/> for support and
165           development: lttng-dev@lists.lttng.org
166
167       •   IRC channel <irc://irc.oftc.net/lttng>: #lttng on irc.oftc.net
168

170       This program is part of the LTTng-tools project.
171
172       LTTng-tools is distributed under the GNU General Public License
173       version 2 <http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html>.
174       See the LICENSE <https://github.com/lttng/lttng-
175       tools/blob/master/LICENSE> file for details.
176

THANKS

178       Special thanks to Michel Dagenais and the DORSAL laboratory
179       <http://www.dorsal.polymtl.ca/> at École Polytechnique de Montréal for
180       the LTTng journey.
181
182       Also thanks to the Ericsson teams working on tracing which helped us
183       greatly with detailed bug reports and unusual test cases.
184

SEE ALSO

186       babeltrace2(1), lttng(1)
187
188
189
190LTTng 2.13.4                     14 June 2021                    LTTNG-VIEW(1)
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