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Show errors in the kernel ring buffer
Much more useful then parsing syslog

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Create a simple video contact sheet using the vcs bash script
Assumes you've downloaded Toni Corvera's vcs script (http://p.outlyer.net/vcs), have it in your PATH, and have installed the script's dependencies. Generates a video contact sheet of 24 thumbnails and 3 thumbnails per column. The bold font and white-on-black color scheme keeps the text readable at the chosen 70% JPEG compression quality, which keeps the file size at a manageable level. You can go even lower with the quality and get a good looking result.

Making scripts runs on backgourd and logging output
Save all output to a log.

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"

encode a text to url_encoded format
usefull for posts via wget

Print entire field if string is detected in column
It searches for a specific value in the specified column and if it finds it it'll print the whole field/row. Similarly, if you don't know what you're looking for exactly but want to exclude something you're already aware of, you can exclude that "something: awk '{ if ($column != "string") print $0}'

Display the number of connections to a MySQL Database
Count the number of active connections to a MySQL database. The MySQL command "show processlist" gives a list of all the active clients. However, by using the processlist table, in the information_schema database, we can sort and count the results within MySQL.

Count the total amount of hours of your music collection
First the find command finds all files in your current directory (.). This is piped to xargs to be able to run the next shell pipeline in parallel. The xargs -P argument specifies how many processes you want to run in parallel, you can set this higher than your core count as the duration reading is mainly IO bound. The -print0 and -0 arguments of find and xargs respectively are used to easily handle files with spaces or other special characters. A subshell is executed by xargs to have a shell pipeline for each file that is found by find. This pipeline extracts the duration and converts it to a format easily parsed by awk. ffmpeg reads the file and prints a lot of information about it, grep extracts the duration line. cut and sed cut out the time information, and tr converts the last . to a : to make it easier to split by awk. awk is a specialized programming language for use in shell scripts. Here we use it to split the time elements in 4 variables and add them up.

return external ip
curl inet-ip.info -> 113.33.232.62\n curl inet-ip.info/ip -> 113.33.232.62 curl inet-ip.info/json -> JSON print curl inet-ip.info/json/indent -> JSON pretty print curl inet-ip.info/yaml -> YAML format curl inet-ip.info/toml -> TOML format http://inet-ip.info

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