The below example involves importing a Zscaler root CA certificate into the java keystore on my Slackware installation.
sudo keytool -import -trustcacerts -alias zscaler -file /etc/ssl/certs/Zscaler-Dalzell.crt -keystore /opt/jdk1.8.0_341/jre/lib/security/cacerts
who -b or uptime -s
To find the last shutdown time, we can do:
last -x | grep shutdown or last -x | grep reboot (output varies between distributions)
I recently came across a system that would not allow me to use legacy boot, so...
We can modify the /etc/paths file or we can create a file under /etc/paths.d such as /etc/paths.d/docker
which could contain;
~/.docker/bin
where the docker bin was located at /Users/my_username/.docker/bin
See also [here] for an example of adding JAVA to the System PATH in Linux.
Often we see an error such as:
ERROR 1129 (HY000): Host 'nn.nn.nn.nn' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'
I found this useful and interesting, especially as the terms are so easily mixed up (by me at least).
Unlocking, rooting, installing a custom recovery, installing Kali and reverting my Nexus 5 back to stock.
Serial port pinouts
Fig's 1&2 show the more common 9 pin serial pinouts, on both the computer side and also the device side respectively. Fig.3 gives a more visual representation of the male variant, most commonly found non the PC side. I think this was historically due to a male being more prone to damage, hence the female end being more commonly used on cables, but I may be wrong.
Fig.5 is particularly useful when testing cables, although I have only really connected pints 2&3 for this purpose. The idea here is that you make a plug that connects the pins together and then you can open the port and whatever you type should be echoed back exactly.
Fig's 6-10 provide details about Null Modem connectivity.
Fig.11 provides more pinout details for the DB25 connectors
We can echo a control char as per the below;
echo -e '\x07'
The above will give us a BEL
if we want to add control characters to a file, we can do;
printf 'hello there \x07 my name is Snake' > test.txt
if we then cat test.txt, well see the text and a BEL
We can of course send this to a serial port with something like cat test.txt > /dev/ttyS0
