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host - DNS lookup utility
host is a simple utility for performing DNS lookups. It is normally used to convert names to IP addresses and vice versa. When no arguments or options are given, host prints a short summary of its command line arguments and options.

Quickest way to sort/display # of occurences

Replace multiple file extensions with a single extension
The above is just a prove of concept based around the nested bash substitution. This could be useful in situations where you're in a directory with many filetypes but you only want to convert a few. $ for f in *.bmp *.jpg *.tga; do convert $f ${f%.*}.png; done or you can use ls | egrep to get more specific... but be warned, files with spaces will cause a ruckus with expansion but the bash for loop uses a space delimited list. $ for f in $(ls | egrep "bmp$|jpg$|tga$"); do convert $f ${f%.*}.png; done I'm guessing some people will still prefer doing it the sed way but I thought the concept of this one was pretty neat. It will help me remember bash substitutions a little better :-P

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Lines per second in a log file

Indicates the position of my monitor buttons
I often need to change the brightness of my monitor. The symbols of the sensor buttons are not illuminated and on a black background .... invisible! Now i use osd_cat instead of a torch ;-)

a function to find the fastest DNS server
http://public-dns.info gives a list of online dns servers. you need to change the country in url (br in this url) with your country code. this command need some time to ping all IP in list.

Shows cpu load in percent
Show the current load of the CPU as a percentage. Read the load from /proc/loadavg and convert it using sed: Strip everything after the first whitespace: $ sed -e 's/ .*//' Delete the decimal point: $ sed -e 's/\.//' Remove leading zeroes: $ sed -e 's/^0*//'

ls only directories
Like normal ls, but only lists directories. Can be used with -l to get more details (ls -lad */)

Wrap text files on the command-line for easy reading
fold wraps text at 80 characters wide, and with the -s flag, only causes wrapping to occur between words rather than through them.


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