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====== How to read logs in *nix cli ======
//
by Patrik Hermansson
//

This is mostly based on the bash terminal but should be more application (less, tail and so on) than the specific terminal.\\
This is also how i use the application listed below to read logs and to troubleshoot.

  * [[howtoreadlogs#Less | Less ]]
  * [[howtoreadlogs#Tail | Tail ]]



===== The commands =====
=== Less ===
[[https://man7.org/linux/man-pages/man1/less.1.html | Less man pages, external link]] \\
Less is the main tool I am using when reading logs. I find the search function good and its quick to open and search in.\\

== Searching in the file ==
/[search pattern] = search from current position for next occurrence in log \\
?[search pattern] = search from current position for previous occurrence in log \\

== How to navigate logs ==
g = go to top of the log (top of file) \\
Can also be used to go to a specific row ''**( g 11 [enter] )**'' g followed by 11 goes to row 11. \\
G = go to the end of log (bottom of file)\\
n = go to next hit down in the search pattern \\
N = go to previous hit up in the search pattern \\
q = quit less \\

=== Tail ===
[[https://man7.org/linux/man-pages/man1/tail.1.html | Less man pages, external link]] \\
Tail is a usefull application for looking att appending logs. Or just the last 10 rows in the logfile. 

I use it for:
  - See the end of the log-file.
  - Let tail print new rows added to the logfile.

  tail {logfile}
This will print out the last 10 rows to standard out = the screen. \\
You can choose the number of files to be printed to screen. Use the -n flag.
  tail -n 20 {logfile}
This will print out the last 20 rows of the logfile.

  tail -f {logfile}
This will print out the last 10 rows and continue to print out rows when they are added to the logfile.

You can also combine the two if you want to see more rows from the logfile at the start.
  tail -f -n 20 {logfile}