This manual page is part of
Cross-Unix
Documentation which is an attempt to provide documentation of
similarities and (noteworthy) differencies between Unix-like systems. To be
used as an addition to the POSIX standard.
regex — Extensions
to POSIX regular expressions
[[:<:]]- Anchors to beginning of a word (4.4BSD, NetBSD, OpenBSD, FreeBSD)
[[:>:]]- Anchors to end of a word (4.4BSD, NetBSD, OpenBSD, FreeBSD)
\<- Anchors to beginning of a word (NetBSD, OpenBSD, FreeBSD, GNU, musl)
\>- Anchors to end of a word (NetBSD, OpenBSD, FreeBSD, GNU, musl)
\b- Matches word boundary (GNU, musl)
\B- Matches word non-boundary characters (GNU, musl)
\w- Matches word characters (GNU)
\W- Matches non-word characters (GNU)
\`- matches the beginning of the whole input (GNU)
\'- matches the beginning of the whole input (GNU)
Derived from laurikari's tre library.
- "[a-z--@] is accepted as [a-z]|[--@]"
- \xHH \x{HHHH}
- \+ and \? treated as repetitions in BRE
- \| as alternation in BRE
- Accept unknown escape char as literal
- "empty branch is unspecified (), (|a), (a|) here they are not
rejected but match on empty string"