Shell Programming and Scripting

This seems to work: -

Code:

nawk '
  { ln = $0}
  /^Key:/{
    ln="Key: "
    for( i = 1; i <= NF; i++)
      if (match($i, /@/))
        ln = ln" "$i
  }
  { sub(/^ /, "", ln)
    print ln
  }
' infile

Thank you everyone, this was great information!

Just out of curiosity, I think the first sed command would have actually worked if the action were negated. (Since it seemed to do the exact opposite thing required). Does anyone have an idea of how that action would be properly negated? or would you negate the string regex instead and keep the action?

I would love to know just to further my own knowledge.