This may happen after a crash.
Problem: You attempt to start your Thunderbird, but its GUI window does not show. You can see it running as a process in the background, but nothing else happens.
Cause: The problem may be caused by a surviving lock file in the user profile directory.
Solution: Navigate to .thunderbird in your user directory, select the appropriate profile directory and delete or remove file .parentlock therein.
To find paragraph breaks (i.e. the ASCII line feed character 0A hex) in LibreOffice, use the currency symbol “$” as the search string.
Make sure to look into “Other options” and check “Regular expressions” in the “Find & Replace” dialog.
By the way, searching for “\n” and replacing it with “\n” can be done only once, as on the repeated action there will be no matches found anymore and searching for “$” must be done instead. Read some more about this bug/feature/inconsistency here.
If you want to see what fonts have been used in creation of a PDF document, you can use pdffonts utility of poppler-utils package for this. Just type:
If you have no automatic certificate renewal, you may found out one day that the browser is telling you that your site is “unsafe” as the certificate has expired.
Just type at the command line:
But you can also add a simple cron job for automatic renewal, for example:
15 5,17 * * * /usr/bin/letsencrypt renew
Checking twice a day is recommended for the unlikely event if something happens to your certificate due to the Let’s Encrypt themselves.
If the certificate is valid and new nothing happens aside from reading the certificate locally, so you can run it as often as you want.
Some of you may have some old Truecrypt volumes lying around. Truecrypt was a nice and handy utility which is not developed anymore, unfortunately. But you still can mount the volumes created by it.
One way to do it on Ubuntu:
sudo cryptsetup tcryptOpen myvol.tc myvol
- myvol.tc – the file name of your volume
- myvol – arbitrary name of the virtual disk to be created
You will be asked for a passphrase, and if you still can remember it, the volume will be mounted under /dev/mapper with the name you provided and will show up as just another disk.
You have a table. The table has a primary key auto-increment numeric ID field. You want to fast-forward the ID to a certain value (which is larger than or equal to the last value the field has).
Example, let the ID of the next entered record be 1000:
ALTER TABLE `mytable` AUTO_INCREMENT = 1000;
You may want to check if all the information available online in regard of your domain is complete and correct.
In such a case you can go to intodns.com and enter the address of your domain to verify the settings.
One thing you will often see failing is “Reverse MX A records (PTR)” for your mail server, and this is a good way to find out if everything is all right or not.