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Delete backward from cursor, useful when you enter the wrong password

Remove blank lines from a file using grep and save output to new file

Generate SHA1 hash for each file in a list
List files and pass to openssl to calculate the hash for each file.

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

Print ASCII Character Chart
Prints out an ascii chart using builtin bash! Then formats using cat -t and column. The best part is: $ echo -e "${p: -3} \\0$(( $i/64*100 + $i%64/8*10 + $i%8 ))"; From: http://www.askapache.com/linux/ascii-codes-and-reference.html

Identify differences between directories (possibly on different servers)
This can be much faster than downloading one or both trees to a common servers and comparing the files there. After, only those files could be copied down for deeper comparison if needed.

get the oldest file in a directory
reverse the sorting of ls to get the newest file: $ls -1tr --group-directories-first /path/to/dir/ | tail -n 1 Problems: If there are no files in the directory you will get a directory or nothing.

Decode base64-encoded file in one line of Perl
Another option is openssl.

make sure you don't add large file to your repository


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