sub­str – Deal with sub­strings in strings

The sub­str pack­age pro­vides com­mands to deal with sub­strings of strings. Macros are pro­vided to: – de­ter­mine if one string is a sub­string of an­other, – re­turn the parts of a string be­fore or af­ter a sub­string and – count the num­ber of oc­cur­rences of a sub­string.