Is there a Linux utility which will return the name of a file only if it contains multiple specified strings? Not necessarily on the same line. Obviously grep can "OR" but I'm looking for "AND".
For simple things you can use
grep command can be used for OR:
Or to match both patterns:
To understand better how to write RegEx patterns, see: https://en.wikipedia.org/wiki/Regular_expression
Really complex parsers can be written with a parser generator like ANTLR