Regular Examples

Real numbers (simple)

[0-9]+\.[0-9]*([eE][+-]?[0-9]+)?

Real numbers (character class)

[[:digit:]]+\.[[:digit:]]*([eE][+-]?[[:digit:]]+)?

Problem: numbers like "3." are acepted, but not ".3".

Real numbers (catch all)

(([[:digit:]]+\.[[:digit:]]*)|(\.[[:digit:]]+))([eE][+-]?[[:digit:]]+)?