Search notes:

/proc/version

/proc/version contains
cat /proc/version might print something like 
Linux version 4.5.0-1-ARCH (builduser@tobias) (gcc version 5.3.0 (GCC) ) #1 SMP PREEMPT Tue Mar 15 09:41:03 CET 2016
Compare the content of /proc/version with the output of uname.

See also

/proc/sys/kernel/osrelease, /proc/sys/kernel/ostype, /proc/sys/kernel/version

Index

Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error: 8 attempt to write a readonly database in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php:78 Stack trace: #0 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(78): PDOStatement->execute(Array) #1 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(30): insert_webrequest_('/notes/Linux/fh...', 1738291539, '3.15.214.244', 'Mozilla/5.0 App...', NULL) #2 /home/httpd/vhosts/renenyffenegger.ch/httpsdocs/notes/Linux/fhs/proc/version(46): insert_webrequest() #3 {main} thrown in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php on line 78