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Prevent overwriting file when using redirection
If you set noclobber to on, bash won't allow redirection to overwrite existing files . $ set -o noclobber command turn the option on (default it s off ) . You can still append information but not overwrite the file .to turn it back off use : $ set +o noclobber . I use it because i overwrite a file by accident , after thought , content of the file was very important , creating a one more file mean nothing for my hard disk (we are not anymore on the 64 k memory time) , but content of file is far much important . What we call exeprience :(

Print every Nth line (to a maximum)
Thanks to knoppix5 for the idea :-) Print selected lines from a file or the output of a command. Usage: $ every NTH MAX [FILE] Print every NTH line (from the first MAX lines) of FILE. If FILE is omitted, stdin is used. The command simply passes the input to a sed script: $ sed -n -e "${2}q" -e "0~${1}p" ${3:-/dev/stdin} print no output $ sed -n quit after this many lines (controlled by the second parameter) $ -e "${2}q" print every NTH line (controlled by the first parameter) $ -e "0~${1}p" take input from $3 (if it exists) otherwise use /dev/stdin ${3:-/dev/stdin}

Detect illegal access to kernel space, potentially useful for Meltdown detection
Based on capsule8 agent examples, not rigorously tested

Search for packages, ranked by popularity
This will take the packages matching a given `apt-cache search` query (a collection of AND'd words or regexps) and tell you how popular they are. This is particularly nice for those times you have to figure out which solution to use for e.g. a PDF reader or a VNC client. Substitute "ubuntu.com" for "debian.org" if you want this to use Ubuntu's data instead. Everything else will work perfectly.

Convert entire audio library in parallel
Uses parallel processing Reiteration of my earlier command https://www.commandlinefu.com/commands/view/15246/convert-entire-music-library Usage lc Old_Directory New_DIrectory Old_Format New_Format lc ~/Music ~/Music_ogg mp3 ogg

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

read Windows ACLs from Linux
You can read, add, delete and modify Windows permissions from Linux using smbcacls from the smb-client package.

grep -v with multiple patterns.
You can use -e to pass multiple patterns.

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" }

Identify all amazon cloudformation scripts recursively using ripgrep
This assumes you are in the cwd of where you put your s3 scripts. Its useful if someone decides to create aws cloudformation scripts and doesn't add the 'yaml' or .yml extension.


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