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Copy via tar pipe while preserving file permissions (cp does not!; run this command with root!)
cp options: -p will preserve the file mode, ownership, and timestamps -r will copy files recursively also, if you want to keep symlinks in addition to the above: use the -a/--archive option

Transforms a file to all uppercase.
Transforms a file to all uppercase.

Remove an IP address ban that has been errantly blacklisted by denyhosts
download the denyhosts-remove script from http://www.atrixnet.com/remove-an-ip-address-ban-that-has-been-errantly-blacklisted-by-denyhosts/

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"

Url Encode
Returns URL Encoded string from input ($1).

Short and elegant way to backup a single file before you change it.
Remember to backup everything before changing it so you can restore all to normal.

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

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" }

list block devices
Shows all block devices in a tree with descruptions of what they are.


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