C:\Tmp>perl -pi -we's{Text::CSV}{Text::CSV_XS}g' xx.pm
Useless use of a constant in void context at -e line 1.
Can't do inplace edit without backup.

C:\Tmp>perl -pi -we"s{Text::CSV}{Text::CSV_XS}g" xx.pm
Can't do inplace edit without backup.

C:\Tmp>perl -pi.bak -we's{Text::CSV}{Text::CSV_XS}g' xx.pm
Useless use of a constant in void context at -e line 1.

C:\Tmp>perl -pi.bak -we"s{Text::CSV}{Text::CSV_XS}g" xx.pm

C:\Tmp>