Awk replace a column with its hash value

Question

How can I replace a column with its hash value (like MD5) in awk or sed?

The original file is super huge, so I need this to be really efficient.

Answer 1

You might have a better time with read than awk, though I haven't done any benchmarking.

the input (scratch001.txt):

foo|bar|foobar|baz|bang|bazbang
baz|bang|bazbang|foo|bar|foobar

transformed using read:

while IFS="|" read -r one fish twofish red fishy bluefishy; do
  twofish=`echo -n $twofish | md5sum | tr -d "  -"`
  echo "$one|$fish|$twofish|$red|$fishy|$bluefishy"
done < scratch001.txt

produces the output:

foo|bar|3858f62230ac3c915f300c664312c63f|baz|bang|bazbang
baz|bang|19e737ea1f14d36fc0a85fbe0c3e76f9|foo|bar|foobar