How can I use (sed|awk) to mask an e-mail address with asterisks like <j******e@g***.com>

Question

How can I mask a list of e-mail addresses like:

John Doe <[email protected]>
John Doe <[email protected]>
Jane Doe <[email protected]>

... with sed (or awk) into something like:

John Doe <j******e@g***l.com>
John Doe <j*****e@h*****l.net>
Jane Doe <j***e@o*****k.org>

In other words: replace most of the e-mail address with asterisks but make it somehow recognizable by users who know the actual e-mail address.

Answer 1

Another Perl version:

perl -pe 's/(<.)(.*)(@.)(.*)(.\..*>)/$1."*" x length($2).$3."*" x length($4).$5/e'

Example:

$ perl -pe 's/(<.)(.*)(@.)(.*)(.\..*>)/$1."*" x length($2).$3."*" x length($4).$5/e' foo
John Doe <j*******@g***l.com>
John Doe <j******@h*****l.net>
Jane Doe <j****@o*****k.org>

With sed, replacing the characters by an equal number of * is complicated. See this SO post for examples involving sed, perl and awk.

Answer 2

Perl to the rescue:

perl -pe '
    sub asteriskify {
        my $s = shift;
        substr $s, 1, -1, "*" x (length($s) - 2);
        return $s
    }
    s/<(.*)@(.*)(?=\..*>)/
        "<" . asteriskify($1) . "@" . asteriskify($2)
    /e;
' < input > output

The substr replaces characters in the string from the second one to the last but one by dots, the number of the dots being the length of the string - 2.

The substitution captures the username to $1 and the domain name without the final part to $2, the ?= part just makes sure it's followed by a dot, whatever and > (see Look Around Assertions in perlre).

Answer 3

Since you asked how to do it with awk, I thought I would prove that it was not too hard. So here goes:

echo "John Doe <[email protected]> John Doe <[email protected]> Jane Doe <[email protected]>" | \
awk \
'
{print repl($0)}

function repl(s, m)
{
  if (match(s,"(<.)([^>]*)(.@.)([^>]*)(.\\.[a-z]*>)", m))
  {
    return substr(s, 1, RSTART-1) m[1] \
           gensub(".","*","g",m[2]) m[3] \
           gensub(".","*","g",m[4]) m[5] \
           repl(substr(s,RSTART+RLENGTH))
  }
  else
    return s
}
'

Answer 4

using sed:

sed 's/.$//' foo.txt | sed 's#\<\(.\).*\(.@.\).*\(\..*\)#\1***\2***\3#'

first sed get rid of the ending >, and 2nd sed will mask the mail address.

output

J****e@g****.com
J****e@h****.net
J****e@o****.org