diff options
Diffstat (limited to 'lib/libc')
| -rw-r--r-- | lib/libc/regex/re_format.7 | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/lib/libc/regex/re_format.7 b/lib/libc/regex/re_format.7 index db2f634..d663f11 100644 --- a/lib/libc/regex/re_format.7 +++ b/lib/libc/regex/re_format.7 @@ -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)', |
