Then you need to swap the part that is searched with the part that is replaced.
Currently, as haukex already explained, you have:
# delimiters
# | | |
# v v v
$localdir =~ s/\//\\/g;
# ^^ ^^
# | |
# search part replacement
So, if you swap search part and replacement, you get:
# delimiters
# | | |
# v v v
$localdir =~ s/\\/\//g;
# ^^ ^^
# | |
# search part replacement
The above gets much clearer if you use another delimiter instead of s///g, for example, s{}{}g. Then your original line is
# delimiters
# | || |
# v vv v
$localdir =~ s{/}{\\}g;
# ^ ^^
# | |
# search part replacement
With the swap of search part and replacement part, that becomes:
<c>
# delimiters
# | || |
# v vv v
$localdir =~ s{\\}{/}g;
# ^^ ^
# | |
# search part replacement
|