system/freebsd-src
system/freebsd-src
1
0
Fork 0
mirror of https://github.com/freebsd/freebsd-src synced 2024-09-24 18:54:52 +00:00
Code Issues Packages Projects Releases Wiki Activity

Note that '+' and '?' are not special characters in basic REs but they

Browse source 
can be simulated using bounds.

PR:		5708
Submitted by:	Oliver Fromme <oliver.fromme@heim3.tu-clausthal.de>
This commit is contained in:
Steve Price 1998-02-14 18:26:29 +00:00
parent a021db1639
commit 0f4b8423e1
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=33352
1 changed files with 5 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
lib/libc/regex/re_format.7
View file

@ -222,8 +222,11 @@ as an implementation can refuse to accept such REs and remain
POSIX-compliant.
.PP
Obsolete (``basic'') regular expressions differ in several respects.
`|', `+', and `?' are ordinary characters and there is no equivalent
for their functionality.
`|' is an ordinary character and there is no equivalent
for its functionality.
`+' and `?' are ordinary characters, and their functionality
can be expressed using bounds (\&{1,\&} or \&{0,1\&} respectively).
Also note that `x+' in modern REs is equivalent to `xx*'.
The delimiters for bounds are `\e{' and `\e}',
with `{' and `}' by themselves ordinary characters.
The parentheses for nested subexpressions are `\e(' and `\e)',