Paul Eggert wrote: > Oh my. For years I thought that gnulib/doc/regex.texi documents the > regular expressions supported by glibc (and by Gnulib, which mimics > glibc). Unfortunately it appears that I am wrong, and it's documentation > for the old GNU regex package (however, with some edits by me that are > appropriate only for glibc!).
Indeed, when I added regex.texi to the Gnulib documentation in 2010 (from the GNU regex 0.12 package, that was on http://ftp.gnu.org/old-gnu/ already at that time), Gnulib had already switched to the regex from glibc - that was in 2005. I wasn't aware that there were significant differences. > Does anybody use gnulib/doc/regex.texi? It is part of the Gnulib documentation [1]. I like it, in particular, because it presents the regular expression syntax as supported by GNU programs in an end-user centric way (what is the syntax for equivalence classes? what does \b mean? etc). Whereas - the glibc documentation [2] describes only the programmer's perspective, - POSIX [3] does not cover the GNU extensions, - The Linux manpage [4] does not cover the GNU extensions either, - The grep documentation [5] describes only the end-user's perspective, and references also PCRE. - The ed documentation [6] and the sed documentation [7] also describe only the end-user's perspective. > If not, I suggest we remove it from Gnulib. It's not part of any > package, and its presence is confusing both Rueben and me. I'd suggest to keep it. If we don't have time for a deep overhaul: please just tell me which nodes of [1] have inaccurate information, and I'll add a big warning "Note: The information on this page is out-of-date!" in each. Further updates can then occur by whoever has time to look into it. Bruno [1] https://www.gnu.org/software/gnulib/manual/html_node/Regular-expressions.html [2] https://www.gnu.org/software/libc/manual/html_node/Regular-Expressions.html [3] https://pubs.opengroup.org/onlinepubs/9699919799.2018edition/basedefs/V1_chap09.html [4] https://man7.org/linux/man-pages/man7/regex.7.html [5] https://www.gnu.org/software/grep/manual/html_node/Regular-Expressions.html [6] https://www.gnu.org/software/ed/manual/ed_manual.html#Regular-expressions [7] https://www.gnu.org/software/sed/manual/html_node/sed-regular-expressions.html
