| 32 |
<li><a name="TOC17" href="#SEC17">BACKREFERENCES</a> |
<li><a name="TOC17" href="#SEC17">BACKREFERENCES</a> |
| 33 |
<li><a name="TOC18" href="#SEC18">SUBROUTINE REFERENCES (POSSIBLY RECURSIVE)</a> |
<li><a name="TOC18" href="#SEC18">SUBROUTINE REFERENCES (POSSIBLY RECURSIVE)</a> |
| 34 |
<li><a name="TOC19" href="#SEC19">CONDITIONAL PATTERNS</a> |
<li><a name="TOC19" href="#SEC19">CONDITIONAL PATTERNS</a> |
| 35 |
<li><a name="TOC20" href="#SEC20">CALLOUTS</a> |
<li><a name="TOC20" href="#SEC20">BACKTRACKING CONTROL</a> |
| 36 |
<li><a name="TOC21" href="#SEC21">SEE ALSO</a> |
<li><a name="TOC21" href="#SEC21">CALLOUTS</a> |
| 37 |
<li><a name="TOC22" href="#SEC22">AUTHOR</a> |
<li><a name="TOC22" href="#SEC22">SEE ALSO</a> |
| 38 |
<li><a name="TOC23" href="#SEC23">REVISION</a> |
<li><a name="TOC23" href="#SEC23">AUTHOR</a> |
| 39 |
|
<li><a name="TOC24" href="#SEC24">REVISION</a> |
| 40 |
</ul> |
</ul> |
| 41 |
<br><a name="SEC1" href="#TOC1">PCRE REGULAR EXPRESSION SYNTAX SUMMARY</a><br> |
<br><a name="SEC1" href="#TOC1">PCRE REGULAR EXPRESSION SYNTAX SUMMARY</a><br> |
| 42 |
<P> |
<P> |
| 376 |
(?(assert)... assertion condition |
(?(assert)... assertion condition |
| 377 |
</PRE> |
</PRE> |
| 378 |
</P> |
</P> |
| 379 |
<br><a name="SEC20" href="#TOC1">CALLOUTS</a><br> |
<br><a name="SEC20" href="#TOC1">BACKTRACKING CONTROL</a><br> |
| 380 |
|
<P> |
| 381 |
|
The following act immediately they are reached: |
| 382 |
|
<pre> |
| 383 |
|
(*ACCEPT) force successful match |
| 384 |
|
(*FAIL) force backtrack; synonym (*F) |
| 385 |
|
</pre> |
| 386 |
|
The following act only when a subsequent match failure causes a backtrack to |
| 387 |
|
reach them. They all force a match failure, but they differ in what happens |
| 388 |
|
afterwards. Those that advance the start-of-match point do so only if the |
| 389 |
|
pattern is not anchored. |
| 390 |
|
<pre> |
| 391 |
|
(*COMMIT) overall failure, no advance of starting point |
| 392 |
|
(*PRUNE) advance to next starting character |
| 393 |
|
(*SKIP) advance start to current matching position |
| 394 |
|
(*THEN) local failure, backtrack to next alternation |
| 395 |
|
</PRE> |
| 396 |
|
</P> |
| 397 |
|
<br><a name="SEC21" href="#TOC1">CALLOUTS</a><br> |
| 398 |
<P> |
<P> |
| 399 |
<pre> |
<pre> |
| 400 |
(?C) callout |
(?C) callout |
| 401 |
(?Cn) callout with data n |
(?Cn) callout with data n |
| 402 |
</PRE> |
</PRE> |
| 403 |
</P> |
</P> |
| 404 |
<br><a name="SEC21" href="#TOC1">SEE ALSO</a><br> |
<br><a name="SEC22" href="#TOC1">SEE ALSO</a><br> |
| 405 |
<P> |
<P> |
| 406 |
<b>pcrepattern</b>(3), <b>pcreapi</b>(3), <b>pcrecallout</b>(3), |
<b>pcrepattern</b>(3), <b>pcreapi</b>(3), <b>pcrecallout</b>(3), |
| 407 |
<b>pcrematching</b>(3), <b>pcre</b>(3). |
<b>pcrematching</b>(3), <b>pcre</b>(3). |
| 408 |
</P> |
</P> |
| 409 |
<br><a name="SEC22" href="#TOC1">AUTHOR</a><br> |
<br><a name="SEC23" href="#TOC1">AUTHOR</a><br> |
| 410 |
<P> |
<P> |
| 411 |
Philip Hazel |
Philip Hazel |
| 412 |
<br> |
<br> |
| 415 |
Cambridge CB2 3QH, England. |
Cambridge CB2 3QH, England. |
| 416 |
<br> |
<br> |
| 417 |
</P> |
</P> |
| 418 |
<br><a name="SEC23" href="#TOC1">REVISION</a><br> |
<br><a name="SEC24" href="#TOC1">REVISION</a><br> |
| 419 |
<P> |
<P> |
| 420 |
Last updated: 06 August 2007 |
Last updated: 08 August 2007 |
| 421 |
<br> |
<br> |
| 422 |
Copyright © 1997-2007 University of Cambridge. |
Copyright © 1997-2007 University of Cambridge. |
| 423 |
<br> |
<br> |