Convert human readable to bytes in bash

Here's a function that understands binary and decimal prefixes and is easily extendable for large units should there be a need:

dehumanise() {
  for v in "${@:-$(</dev/stdin)}"
  do  
    echo $v | awk \
      'BEGIN{IGNORECASE = 1}
       function printpower(n,b,p) {printf "%u\n", n*b^p; next}
       /[0-9]$/{print $1;next};
       /K(iB)?$/{printpower($1,  2, 10)};
       /M(iB)?$/{printpower($1,  2, 20)};
       /G(iB)?$/{printpower($1,  2, 30)};
       /T(iB)?$/{printpower($1,  2, 40)};
       /KB$/{    printpower($1, 10,  3)};
       /MB$/{    printpower($1, 10,  6)};
       /GB$/{    printpower($1, 10,  9)};
       /TB$/{    printpower($1, 10, 12)}'
  done
} 

example:

$ dehumanise 2K 2k 2KiB 2KB 
2048
2048
2048
2000

$ dehumanise 2G 2g 2GiB 2GB 
2147483648
2147483648
2147483648
2000000000

The suffixes are case-insensitive.

Use numfmt --from=iec from GNU coreutils.