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--- tipsandtricks:howtoreadlogs [2021/11/16 08:43] – created patrik
+++ tipsandtricks:howtoreadlogs [2023/09/29 07:01] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
 [[https://techwiki.keepthelogs.com | <== Back to menu]] \\
 [[sections:tipsandtricks|<= Back]]
+====== 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}