Remove non-alpha characters before a character from every line of a text file

Question

I have a text file that looks like this:

13foobar@example.com
foo.bar3@example2.com
qwerty-1@dept.example3.com

How can I use sed or perl to remove all non-alpha characters before the @ sign. I.e. the desired output would be:

foobar@example.com
foobar@example2.com
qwerty@dept.example3.com

score 1 · Answer 1 · answered Aug 26 '15 at 02:58

1

The following one-liner should suffice.

perl -pe 's/[^a-z]+(?=[^@\n]*@)//g'

answered Aug 26 '15 at 02:58

hwnd

Generally speaking, this a bad approach since it's O(N^2). However, since the OP's input will be limited in length in practice, that's not relevant for him. – ikegami Aug 26 '15 at 03:35
@ikegami, In general I certainly agree, but for this case it would be alright. – hwnd Aug 26 '15 at 03:42

score 0 · Accepted Answer · edited Aug 26 '15 at 03:24

0

Input

13foobar@example.com
foo.bar3@example2.com
qwerty-1@dept.example3.com

Perl one-liner

perl -ne 'my ($user,$host) = split /\@/; $user =~ s/[\W\d]//g; print $user . "@" . $host;'

In action

cat input | perl -ne 'my ($user,$host) = split /\@/; $user =~ s/[\W\d]//g; print $user . "@" . $host;'

Output

foobar@example.com
foobar@example2.com
qwerty@dept.example3.com

edited Aug 26 '15 at 03:24

nhahtdh

answered Aug 26 '15 at 02:57

xxfelixxx

2 Answers2