295 |
.P |
.P |
296 |
All the sequences that define a single character value can be used both inside |
All the sequences that define a single character value can be used both inside |
297 |
and outside character classes. In addition, inside a character class, the |
and outside character classes. In addition, inside a character class, the |
298 |
sequence \eb is interpreted as the backspace character (hex 08), and the |
sequence \eb is interpreted as the backspace character (hex 08). The sequences |
299 |
sequences \eR and \eX are interpreted as the characters "R" and "X", |
\eB, \eR, and \eX are not special inside a character class. Like any other |
300 |
respectively. Outside a character class, these sequences have different |
unrecognized escape sequences, they are treated as the literal characters "B", |
301 |
meanings |
"R", and "X" by default, but cause an error if the PCRE_EXTRA option is set. |
302 |
|
Outside a character class, these sequences have different meanings |
303 |
.\" HTML <a href="#uniextseq"> |
.\" HTML <a href="#uniextseq"> |
304 |
.\" </a> |
.\" </a> |
305 |
(see below). |
(see below). |
479 |
.sp |
.sp |
480 |
(*ANY)(*BSR_ANYCRLF) |
(*ANY)(*BSR_ANYCRLF) |
481 |
.sp |
.sp |
482 |
Inside a character class, \eR matches the letter "R". |
Inside a character class, \eR is treated as an unrecognized escape sequence, |
483 |
|
and so matches the letter "R" by default, but causes an error if PCRE_EXTRA is |
484 |
|
set. |
485 |
. |
. |
486 |
. |
. |
487 |
.\" HTML <a name="uniextseq"></a> |
.\" HTML <a name="uniextseq"></a> |
768 |
\ez matches only at the end of the subject |
\ez matches only at the end of the subject |
769 |
\eG matches at the first matching position in the subject |
\eG matches at the first matching position in the subject |
770 |
.sp |
.sp |
771 |
These assertions may not appear in character classes (but note that \eb has a |
Inside a character class, \eb has a different meaning; it matches the backspace |
772 |
different meaning, namely the backspace character, inside a character class). |
character. If any other of these assertions appears in a character class, by |
773 |
|
default it matches the corresponding literal character (for example, \eB |
774 |
|
matches the letter B). However, if the PCRE_EXTRA option is set, an "invalid |
775 |
|
escape sequence" error is generated instead. |
776 |
.P |
.P |
777 |
A word boundary is a position in the subject string where the current character |
A word boundary is a position in the subject string where the current character |
778 |
and the previous character do not both match \ew or \eW (i.e. one matches |
and the previous character do not both match \ew or \eW (i.e. one matches |
2586 |
.rs |
.rs |
2587 |
.sp |
.sp |
2588 |
.nf |
.nf |
2589 |
Last updated: 27 March 2010 |
Last updated: 03 May 2010 |
2590 |
Copyright (c) 1997-2010 University of Cambridge. |
Copyright (c) 1997-2010 University of Cambridge. |
2591 |
.fi |
.fi |