Taylor Blau <me@xxxxxxxxxxxx> writes: > *Grumble*, it's not anywhere in POSIX: > > https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html > > ...making this a GNU-ism. > >> Look for "stick to a subset of BRE" in Documention/CodingGuidelines; >> we may need to update the document to raise the baseline to match >> the reality of year 2020, though. > > So, I think the "reality of year 2020" is that we still write '..*' > instead of '.\+'. Another interesting thing I found is this piece in "man sed" on Linux (hence GNU): REGULAR EXPRESSIONS ... The -E option switches to using extended regular expressions instead; it has been supported for years by GNU sed, and is now included in POSIX. But the "sed" documentation [*1*] that matches what you cited above (The Open Group Base Specifications Issue 7, 2018 edition) does not mention "-E", "-r" nor "--regexp-extended". [Reference] *1* https://pubs.opengroup.org/onlinepubs/9699919799/utilities/sed.html#tag_20_116_02
