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find available cpu frequencies on FreeBSD
Once you know the available frequencies for your CPU, they can be used to do things like set minimum CPU frequency for powerd so that it doesn't ramp down too slow on a server : /etc/sysctl.conf or /boot/loader.conf: debug.cpufreq.lowest=DESIRED FREQ HERE or at terminal sysctl debug.cpufreq.lowest=DESIRED FREQ HERE

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Create multiple subfolders in one command.
Instead of typing separate commands to create various subfolders, we can create multiple subfolders by listing them between brackets and separated by commas.

ANSI Terminal Color Test using python
Pre-packaged python script that comes with Debian/Ubuntu.

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

make image semi-transparent

Remount a usb disk in Gnome without physically removing and reinserting
Remounts a usb disk /dev/sdb, without having to physically remove and reinsert. (Gnome desktop)

Safe Delete
remove file that has sensitive info safely. Overwrites it 33 times with zeros

A simple way to securely use passwords on the command line or in scripts
In this example, where the users gpg keyring has a password, the user will be interactively prompted for the keyring password. If the keyring has no password, same as above, sans the prompt. Suitable for cron jobs. ~/.gnupg/passwd/http-auth.gpg is the encrypted http auth password, for this particular wget use case. This approach has many use cases. example bash functions: function http_auth_pass() { gpg2 --decrypt ~/.gnupg/passwd/http-auth.gpg 2>/dev/null; } function decrypt_pass() { gpg2 --decrypt ~/.gnupg/passwd/"$1" 2>/dev/null; }

Backup all starred repositories from Github


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