course i taught last week provided courseware that distinguished between grep's basic RE support and "extended" RE support, which surprised me as, on my fedora 27 system, the man page for grep has the following snippets: "In addition, the variant programs egrep and fgrep are the same as grep -E and grep -F, respectively. These variants are deprecated, but are provided for backward compatibility." also, further down: "grep understands three different versions of regular expression syntax: “basic” (BRE), “extended” (ERE) and “perl” (PCRE). In GNU grep there is no difference in available functionality between basic and extended syntaxes." that *seems* pretty clear, but i just want to confirm that, in gnu grep these days, the extended REs are now available automatically and don't require options like they used to. thoughts? rday