"process substitution" is one of the new useful things I learned this year (switched to bash from csh over 20 years ago). /proc/${pid}/fd/ is very useful for f

"process substitution" is one of the new useful things I learned this year (switched to bash from csh over 20 years ago). /proc/${pid}/fd/ is very useful for forensic purposes when you find some malware running that deleted itself and/or config files but still has a handle open to them.