lnav/docs/tutorials/tutorial1/index.md

6.1 KiB

name steps
tutorial1
move-to-error move-to-warning
description view_ptr view_value notification comment
Move to an error /top 6 Press `e`/`Shift+E` to move through the <span class="-lnav_log-level-styles_error">errors</span> You found the error! [Log formats](https://docs.lnav.org/en/latest/formats.html#format-file-reference) can define the log levels for a given message. The [theme](https://docs.lnav.org/en/latest/config.html#theme-definitions) defines how the levels are displayed.
description notification view_ptr view_value comment
Move to a warning Press `w`/`Shift+W` to move through the <span class="-lnav_log-level-styles_warning">warnings</span> /top 3 You found the warning! The scrollbar on the right is highlighted to show the position of <span class="-lnav_log-level-styles_warning">warnings</span> and <span class="-lnav_log-level-styles_error">errors</span> in this view.
search-for-term move-to-next-hit move-right
description notification view_ptr view_value
Search for something Press `/` to search for '1AF9...' /search 1AF9293A-F42D-4318-BCDF-60234B240955
description notification view_ptr view_value comment
Move to the next hit Press `n`/`Shift+N` to move through the search hits /top 53 The matching text in a search is highlighted in <span class="-lnav_styles_search">reverse-video</span>. However, the text is not always on-screen, so the bar on the left will also be highlighted. You can then press `>` to move right to the next (horizontal) search hit. Pressing `<` will move left to the previous (horizontal) hit or all the way back to the start of the line.
description notification view_ptr view_value
Move to the right Press `>` to move horizontally to view the search hit /left 582
move-to-half-hour move-to-timestamp
description notification view_ptr view_value comment
Move to the next half-hour Press `3`/`Shift+3` to move through the half-hour marks /top 34 This file is in the _glog_ format and timestamps consist of the year, month, and day squished together. This log message's timestamp is March 22nd, 2017. You can see the timestamp for the top line in the view in the breadcrumb bar. Next, go to the log messages for the following day using `:goto March 23` or the breadcrumb bar above.
description notification view_ptr view_value comment
Move to a given timestamp Move to '**March 23**' using `:goto` or the breadcrumb bar /top 79 Many different timestamp formats are recognized as well as relative times, like `+1h` or `-2h`.

Tutorial 1

Welcome to the first interactive lnav tutorial!

This tutorial will guide you through the basics of navigating log files. Pressing q will display an example log file to try out commands on. Pressing y will return you to the next step in the tutorial.

Step 1

Finding errors quickly is one of the main use-cases for lnav. To make that quick and easy, lnav parses the log messages in log files as they are loaded and builds indexes of the errors and warnings. You can then use the following hotkeys to jump to them in the log view:

Key Action
e Move to the next error
Shift+E Move to the previous error
w Move to the next warning
Shift+W Move to the previous warning

To complete this step in the tutorial, you'll need to navigate to the errors and warnings in the sample log file. You can check the upper-right ↗↗↗ status bar for tips on what you need to do next. Now, press q to switch to the log view and begin navigating the sample log file.

Step 2

To search for text in files, you can press / to enter the search prompt. To make it easier to search for text that is on-screen, you can press TAB to complete values that are shown on screen. For example, to search for the UUID "1AF9293A-F42D-4318-BCDF-60234B240955" that is in one of the error messages, you can enter "1AF9" and then press TAB to complete the rest of the UUID.

Press q to switch to the log view and try searching for the UUID.

Step 3

To move to a particular time in the logs, you have a few options:

  • The number keys can be used to move to messages at the ten-minute marks within an hour. For example, pressing 2 will move to the first message after the next twenty-minute mark, pressing 3 will move to the next half-hour mark, and so on.
  • Pressing ENTER to focus on the breadcrumb bar, then you can press TAB (or right-arrow) to move to the time crumb. With the time crumb selected, you can then type in an absolute or relative time. Or, you can use the up and down arrow keys to select a preset relative time.
  • Pressing : will activate the command prompt, then you can use the :goto command to move to a given timestamp (or line number).

Press q to switch to the log view and try moving to different times.

Conclusion

That's all for now, thanks for your time! Visit the downloads page to find out how to download or install lnav for your system. The full documentation is available at https://docs.lnav.org

Press q to switch to the log view and then press q again to exit lnav.

Colophon

The source for this tutorial is available here:

https://github.com/tstack/lnav/tree/master/docs/tutorials/