Search notes:

~/.mozilla/firefox/profiles.ini

The profiles.ini file for Firefox in a Linux installation.
[General]
StartWithLastProfile=1

[Profile0]
Name=default
IsRelative=1
Path=abcd5678_default
Default=1
StartWithLastProfile=1 indicates that the profile with Default=1 should be started. StartWithLastProfile=0 would cause Firefox to ask the user which profile should be used.
IsRelative=1 indicates that the profile folder is below the folder in which the profiles.ini file is found.

Installation of 2020-09-05 (Windows)

After a fresh installation on Windows (2020-09-05), I found this profiles.ini file:
[Install308046B0AF4A39CB]
Default=Profiles/811jxeb3.default-release
Locked=1

[Profile1]
Name=default
IsRelative=1
Path=Profiles/q411pdtw.default
Default=1

[Profile0]
Name=default-release
IsRelative=1
Path=Profiles/811jxeb3.default-release

[General]
StartWithLastProfile=1
Version=2

TODO

Apparently, the same format is also used as profiles.ini file for Thunderbird and SeaMonkey.

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...', 1758207814, '216.73.216.150', 'Mozilla/5.0 App...', NULL) #2 /home/httpd/vhosts/renenyffenegger.ch/httpsdocs/notes/Linux/fhs/home/username/_mozilla/firefox/profiles_ini(75): insert_webrequest() #3 {main} thrown in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php on line 78