Commands by sixtus (2)

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Calculate days on which Friday the 13th occurs (inspired from the work of the user justsomeguy)
Friday is the 5th day of the week, monday is the 1st. Output may be affected by locale.

Testing reading speed with dd

Show what PID is listening on port 80 on Linux

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" }

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" }

find your release version of your ubuntu / debian distro

Display GCC Predefined Macros

Convert all .flac from a folder subtree in 192Kb mp3
find . -type f -iname '*.flac' # searches from the current folder recursively for .flac audio files | # the output (a .flac audio files with relative path from ./ ) is piped to while read FILE; do FILENAME="${FILE%.*}"; flac -cd "$FILE" | lame -b 192 - "${FILENAME}.mp3"; done # for each line on the list: # FILE gets the file with .flac extension and relative path # FILENAME gets FILE without the .flac extension # run flac for that FILE with output piped to lame conversion to mp3 using 192Kb bitrate

TCPDUMP & Save Capture to Remote Server w/ GZIP
NOTE: When opening the files you might need to strip the very top line with notepad++ as its a mistake header This is useful when the local machine where you need to do the packet capture with tcpdump doesn?t have enough room to save the file, where as your remote host does tcpdump -i eth0 -w - | ssh forge.remotehost.com -c arcfour,blowfish-cbc -C -p 50005 "cat - | gzip > /tmp/eth0.pcap.gz" Your @ PC1 doing a tcpdump of PC1s eth0 interface and its going to save the output @ PC2 who is called save.location.com to a file /tmp/eth0-to-me.pcap.gz again on PC2 More info @: http://www.kossboss.com/linuxtcpdump1

Reclaim standard in from the tty for a script that is in a pipeline
This will grab the controlling tty regardless of what STDOUT and STDERR are doing.

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