Don't recompute sort keys inside a sort. [Sorting]
Use reverse to reverse a list. [Reversing Lists]
Use scalar reverse to reverse a scalar. [Reversing Scalars]
Use unpack to extract fixed-width fields. [Fixed-Width Data]
Use split to extract simple variable-width fields. [Separated Data]
Use Text::CSV_XS to extract complex variable-width fields. [Variable-Width Data]
Avoid string eval. [String Evaluations]
Consider building your sorting routines with Sort::Maker. [Automating Sorts]
Use 4-arg substr instead of lvalue substr. [Substrings]
Make appropriate use of lvalue values. [Hash Values]
Use glob, not <...>. [Globbing]
Avoid a raw select for non-integer sleeps. [Sleeping]
Always use a block with a map and grep. [Mapping and Grepping]
Use the "non-builtin builtins". [Utilities]