In general, chomp() can be trusted to remove a trailing carriage return from your string. If chomp() doesn't work, then perhaps your string doesn't contain what you think it does.

A few obvious problems with your regular expression:

• you are quoting it AND using the forward-slash characters to delimit your regex
• you seem to be looking for a literal '$' character at the end of your string

If I was looking for a series of word characters, I might prefer something like this, which looks for one or more characters in the word character class at the beginning of the string, and greedily captures them all into the $1 variable:

  my $trimmed_user;
  if ($user =~ /^(\w+)/) {
    $trimmed_user = $1;
  }
[download]

Of course, this assumes that you won't have any characters in a user name that are not in the word character class (A-Za-z0-9_).