notes

To check if ca-certificates package is installed run this command:

dpkg -s ca-certificates

To print exit code of the last command type:

echo $?

If you want to inspect what queries exactly Django ORM sends to the PostgreSQL, you can do it with postgres logging. The first step is to enable logging. Add

log_statement = 'all'

to the file:

sudo vim /etc/postgresql/9.4/main/postgresql.conf

Then you are able to see raw SQL queries with command:

sudo tail -f /var/log/postgresql/postgresql-9.4-main.log

Sometimes I’m unable to create a database in UTF8 encoding because the template database is in the ASCII encoding. To fix it we need to recreate template database in UTF8. Start psql console:

psql -U postgres

Run the following commands:

UPDATE pg_database SET datistemplate = FALSE WHERE datname = 'template1';

DROP DATABASE template1;

CREATE DATABASE template1 WITH TEMPLATE = template0 ENCODING = 'UNICODE';

UPDATE pg_database SET datistemplate = TRUE WHERE datname = 'template1';

\c template1

VACUUM FREEZE;

Open configuration file:

sudo vim /etc/sysctl.d/90-override.conf

Add the following line to the end of the file to increase watches limit:

fs.inotify.max_user_watches = 524288

First step is to find the name of the USB stick in the system:

sudo fdisk -l

In my case the name of the device is /dev/sdc If the USB stick is mounted, unmount it with command:

sudo umount /dev/sdc

Finally, run the command to format USB stick:

mkdosfs -F 32 -I /dev/sdc

Remove all *.pyc files from the current directory (and subdirectories):

find . -name \*.pyc -delete

Remove

text/plain=komodo-edit-9.desktop

from file

~/.local/share/applications/defaults.list

To start an application automatically in fedora, you need to create a *.desktop file in the directory ~/.config/autostart, for example:

gedit ~/.config/autostart/flux.desktop

The content of the file can be something like:

[Desktop Entry]
Type=Application
Name=flux
Comment=xflux
Exec=/home/jsn/app/xflux -l 52.3837151 -g 4.8806328
Terminal=false

If you need to find out, for example, which package in fedora provides htpasswd command, you may do it with the command:

yum provides \*bin/htpasswd