summaryrefslogtreecommitdiffstats
path: root/docs/manual/mod/mod_rewrite.xml
blob: c12df7f3519b067bf218a365f87b1770e442ae80 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
<?xml version="1.0"?>
<!DOCTYPE modulesynopsis SYSTEM "../style/modulesynopsis.dtd">
<?xml-stylesheet type="text/xsl" href="../style/manual.en.xsl"?>
<!-- $LastChangedRevision$ -->

<!--
 Licensed to the Apache Software Foundation (ASF) under one or more
 contributor license agreements.  See the NOTICE file distributed with
 this work for additional information regarding copyright ownership.
 The ASF licenses this file to You under the Apache License, Version 2.0
 (the "License"); you may not use this file except in compliance with
 the License.  You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
-->

<modulesynopsis metafile="mod_rewrite.xml.meta">

<name>mod_rewrite</name>

<description>Provides a rule-based rewriting engine to rewrite requested
URLs on the fly</description>

<status>Extension</status>
<sourcefile>mod_rewrite.c</sourcefile>
<identifier>rewrite_module</identifier>

<summary>
	<p>The <module>mod_rewrite</module> module uses a rule-based rewriting
      engine, based on a regular-expression parser, to rewrite requested URLs on
      the fly. By default, <module>mod_rewrite</module> maps a URL to a filesystem
      path. However, it can also be used to redirect one URL to another URL, or
      to invoke an internal proxy fetch.</p>
      <p><module>mod_rewrite</module> provides a flexible and powerful way to
      manipulate URLs using an unlimited number of rules. Each rule can have an
      unlimited number of attached rule conditions, to allow you to rewrite URL
      based on server variables, environment variables, HTTP headers, or time
      stamps.</p>
      <p><module>mod_rewrite</module> operates on the full URL path, including the
      path-info section. A rewrite rule can be invoked in
      <code>httpd.conf</code> or in <code>.htaccess</code>. The path generated
      by a rewrite rule can include a query string, or can lead to internal
      sub-processing, external request redirection, or internal proxy
      throughput.</p>

      <p>Further details, discussion, and examples, are provided in the
      <a href="../rewrite/">detailed mod_rewrite documentation</a>.</p>
</summary>

<section id="logging"><title>Logging</title>

    <p><module>mod_rewrite</module> offers detailed logging of its actions
    at the <code>trace1</code> to <code>trace8</code> log levels. The
    log level can be set specifically for <module>mod_rewrite</module>
    using the <directive module="core">LogLevel</directive> directive: Up to
    level <code>debug</code>, no actions are logged, while <code>trace8</code>
    means that practically all actions are logged.</p>

    <note>
      Using a high trace log level for <module>mod_rewrite</module>
      will slow down your Apache HTTP Server dramatically! Use a log
      level higher than <code>trace2</code> only for debugging!
    </note>

    <example><title>Example</title>
      LogLevel alert rewrite:trace3
    </example>

    <note><title>RewriteLog</title>
      <p>Those familiar with earlier versions of
      <module>mod_rewrite</module> will no doubt be looking for the
      <code>RewriteLog</code> and <code>RewriteLogLevel</code>
      directives. This functionality has been completely replaced by the
      new per-module logging configuration mentioned above.
      </p>

      <p>To get just the <module>mod_rewrite</module>-specific log
      messages, pipe the log file through grep:</p>
    <example>
    tail -f error_log|fgrep '[rewrite:'
    </example>
    </note>

</section>

<directivesynopsis>
<name>RewriteEngine</name>
<description>Enables or disables runtime rewriting engine</description>
<syntax>RewriteEngine on|off</syntax>
<default>RewriteEngine off</default>
<contextlist><context>server config</context><context>virtual host</context>
<context>directory</context><context>.htaccess</context></contextlist>
<override>FileInfo</override>

<usage>

      <p>The <directive>RewriteEngine</directive> directive enables or
      disables the runtime rewriting engine. If it is set to
      <code>off</code> this module does no runtime processing at
      all. It does not even update the <code>SCRIPT_URx</code>
      environment variables.</p>

      <p>Use this directive to disable the module instead of
      commenting out all the <directive
      module="mod_rewrite">RewriteRule</directive> directives!</p>

      <p>Note that rewrite configurations are not
      inherited by virtual hosts. This means that you need to have a
      <code>RewriteEngine on</code> directive for each virtual host
      in which you wish to use rewrite rules.</p>

      <p><directive>RewriteMap</directive> directives of the type <code>prg</code>
      are not started during server initialization if they're defined in a
      context that does not have <directive>RewriteEngine</directive>  set to
      <code>on</code></p>
</usage>

</directivesynopsis>

<directivesynopsis>
<name>RewriteOptions</name>
<description>Sets some special options for the rewrite engine</description>
<syntax>RewriteOptions <var>Options</var></syntax>
<contextlist><context>server config</context><context>virtual host</context>
<context>directory</context><context>.htaccess</context></contextlist>
<override>FileInfo</override>
<compatibility><code>MaxRedirects</code> is no longer available in version 2.1 and
later</compatibility>
<usage>

      <p>The <directive>RewriteOptions</directive> directive sets some
      special options for the current per-server or per-directory
      configuration. The <em>Option</em> string can currently
      only be one of the following:</p>

      <dl>
      <dt><code>Inherit</code></dt>
      <dd>

      <p>This forces the current configuration to inherit the
      configuration of the parent. In per-virtual-server context,
      this means that the maps, conditions and rules of the main
      server are inherited. In per-directory context this means
      that conditions and rules of the parent directory's
      <code>.htaccess</code> configuration or
      <directive type="section" module="core">Directory</directive>
      sections are inherited. The inherited rules are virtually copied
      to the section where this directive is being used. If used in
      combination with local rules, the inherited rules are copied behind
      the local rules. The position of this directive - below or above
      of local rules - has no influence on this behavior. If local
      rules forced the rewriting to stop, the inherited rules won't
      be processed.</p>

      <note type="warning">
      Rules inherited from the parent scope are applied
      <strong>after</strong> rules specified in the child scope.
      </note>
      </dd>

      <dt><code>InheritBefore</code></dt>
      <dd>
      <p> Like <code>Inherit</code> above, but the rules from the parent scope
      are applied <strong>before</strong> rules specified in the child scope.
      Available in Apache HTTP Server 2.3.10 and later.</p>
      </dd>

      </dl>

</usage>

</directivesynopsis>

<directivesynopsis>
<name>RewriteMap</name>
<description>Defines a mapping function for key-lookup</description>
<syntax>RewriteMap <em>MapName</em> <em>MapType</em>:<em>MapSource</em>
</syntax>
<contextlist><context>server config</context><context>virtual host</context>
</contextlist>
<compatibility>The choice of different dbm types is available in
Apache HTTP Server 2.0.41 and later</compatibility>

<usage>
      <p>The <directive>RewriteMap</directive> directive defines a
      <em>Rewriting Map</em> which can be used inside rule
      substitution strings by the mapping-functions to
      insert/substitute fields through a key lookup. The source of
      this lookup can be of various types.</p>

      <p>The <a id="mapfunc" name="mapfunc"><em>MapName</em></a> is
      the name of the map and will be used to specify a
      mapping-function for the substitution strings of a rewriting
      rule via one of the following constructs:</p>

      <p class="indent">
        <strong><code>${</code> <em>MapName</em> <code>:</code>
        <em>LookupKey</em> <code>}</code><br />
         <code>${</code> <em>MapName</em> <code>:</code>
        <em>LookupKey</em> <code>|</code> <em>DefaultValue</em>
        <code>}</code></strong>
      </p>

      <p>When such a construct occurs, the map <em>MapName</em> is
      consulted and the key <em>LookupKey</em> is looked-up. If the
      key is found, the map-function construct is substituted by
      <em>SubstValue</em>. If the key is not found then it is
      substituted by <em>DefaultValue</em> or by the empty string
      if no <em>DefaultValue</em> was specified. Empty values
      behave as if the key was absent, therefore it is not possible
      to distinguish between empty-valued keys and absent keys.</p>

      <p>For example, you might define a
      <directive>RewriteMap</directive> as:</p>

      <example>
      RewriteMap examplemap txt:/path/to/file/map.txt
      </example>

      <p>You would then be able to use this map in a
      <directive>RewriteRule</directive> as follows:</p>

      <example>
      RewriteRule ^/ex/(.*) ${examplemap:$1}
      </example>

      <p>The following combinations for <em>MapType</em> and
      <em>MapSource</em> can be used:</p>

    <dl>

    <dt>txt</dt>
        <dd>A plain text file containing space-separated key-value
        pairs, one per line. (<a href="../rewrite/rewritemap.html#txt">Details ...</a>)</dd>

    <dt>rnd</dt>
        <dd>Randomly selects an entry from a plain text file (<a href="../rewrite/rewritemap.html#rnd">Details ...</a>)</dd>

    <dt>dbm</dt>
        <dd>Looks up an entry in a dbm file containing name, value
        pairs. Hash is constructed from a plain text file format using
        the <code><a href="../programs/httxt2dbm.html">httxt2dbm</a></code>
        utility.  (<a href="../rewrite/rewritemap.html#dbm">Details ...</a>)</dd>

    <dt>int</dt>
        <dd>One of the four available internal functions provided by
        <code>RewriteMap</code>: toupper, tolower, escape or
        unescape. (<a href="../rewrite/rewritemap.html#int">Details ...</a>)</dd>

    <dt>prg</dt>
        <dd>Calls an external program or script to process the
        rewriting. (<a href="../rewrite/rewritemap.html#prg">Details ...</a>)</dd>

    <dt>dbd or fastdbd</dt>
        <dd>A SQL SELECT statement to be performed to look up the
        rewrite target. (<a href="../rewrite/rewritemap.html#dbd">Details ...</a>)</dd>
    </dl>

    <p>Further details, and numerous examples, may be found in the <a
    href="../rewrite/rewritemap.html">RewriteMap HowTo</a></p>

</usage>
</directivesynopsis>

<directivesynopsis>
<name>RewriteBase</name>
<description>Sets the base URL for per-directory rewrites</description>
<syntax>RewriteBase <em>URL-path</em></syntax>
<default>None</default>
<contextlist><context>directory</context><context>.htaccess</context>
</contextlist>
<override>FileInfo</override>

<usage>
      <p>The <directive>RewriteBase</directive> directive explicitly
      sets the base URL-path (not filesystem directory path!)  for per-directory rewrites
      that result in the substitution of a relative path.
      When you use a <directive module="mod_rewrite">RewriteRule</directive>
      in a <code>.htaccess</code> file, <module>mod_rewrite</module> strips off
      the local directory prefix before processing, then rewrites the rest of
      the URL. When the rewrite is completed, <module>mod_rewrite</module>
      automatically adds the local directory prefix (or the
      <directive>RewriteBase</directive> when set) back on to the substitution
      before handing it back to the core of the server as if it were the original
      URL.</p>

      <p>This directive is <em>required</em> for per-directory rewrites whose context
      is a directory made available via the <directive module="mod_alias">Alias</directive>
      directive, when the substitution uses a relative path.</p>

      <p>If your URL path does not exist verbatim on the filesystem,
      or isn't directly under your <directive module="core">DocumentRoot</directive>,
      you must use <directive>RewriteBase</directive> in every
      <code>.htaccess</code> file where you want to use <directive
      module="mod_rewrite">RewriteRule</directive> directives.</p>

      <p>The example below demonstrates how to map
      http://example.com/myapp/index.html to
      /home/www/example/newsite.html, in a <code>.htaccess</code> file. This
      assumes that the content available at
      http://example.com/ is on disk at /home/www/example/</p>
<example>
<pre>
RewriteEngine On
# The URL-path used to get to this context, not the filesystem path
RewriteBase /myapp/
RewriteRule ^index\.html$  newsite.html
</pre>
</example>

</usage>

</directivesynopsis>

<directivesynopsis>
<name>RewriteCond</name>
<description>Defines a condition under which rewriting will take place
</description>
<syntax> RewriteCond
      <em>TestString</em> <em>CondPattern</em></syntax>
<contextlist><context>server config</context><context>virtual host</context>
<context>directory</context><context>.htaccess</context></contextlist>
<override>FileInfo</override>

<usage>
      <p>The <directive>RewriteCond</directive> directive defines a
      rule condition. One or more <directive>RewriteCond</directive>
      can precede a <directive module="mod_rewrite">RewriteRule</directive>
      directive. The following rule is then only used if both
      the current state of the URI matches its pattern, <strong
      >and</strong> if these conditions are met.</p>

      <p><em>TestString</em> is a string which can contain the
      following expanded constructs in addition to plain text:</p>

      <ul>
        <li>
          <strong>RewriteRule backreferences</strong>: These are
          backreferences of the form <strong><code>$N</code></strong>
          (0 &lt;= N &lt;= 9). $1 to $9 provide access to the grouped
          parts (in parentheses) of the pattern, from the
          <code>RewriteRule</code> which is subject to the current
          set of <code>RewriteCond</code> conditions. $0 provides
          access to the whole string matched by that pattern.
        </li>
        <li>
          <strong>RewriteCond backreferences</strong>: These are
          backreferences of the form <strong><code>%N</code></strong>
          (0 &lt;= N &lt;= 9). %1 to %9 provide access to the grouped
          parts (again, in parentheses) of the pattern, from the last matched
          <code>RewriteCond</code> in the current set
          of conditions. %0 provides access to the whole string matched by
          that pattern.
        </li>
        <li>
          <strong>RewriteMap expansions</strong>: These are
          expansions of the form <strong><code
          >${mapname:key|default}</code></strong>.
          See <a href="#mapfunc">the documentation for
          RewriteMap</a> for more details.
        </li>
        <li>
          <strong>Server-Variables</strong>: These are variables of
          the form
            <strong><code>%{</code> <em>NAME_OF_VARIABLE</em>
            <code>}</code></strong>
          where <em>NAME_OF_VARIABLE</em> can be a string taken
          from the following list:

          <table>
          <columnspec><column width=".3"/><column width=".3"/>
           <column width=".3"/></columnspec>
            <tr>
              <th>HTTP headers:</th> <th>connection &amp; request:</th> <th></th>
            </tr>

            <tr>
              <td>
                 HTTP_USER_AGENT<br />
                 HTTP_REFERER<br />
                 HTTP_COOKIE<br />
                 HTTP_FORWARDED<br />
                 HTTP_HOST<br />
                 HTTP_PROXY_CONNECTION<br />
                 HTTP_ACCEPT<br />
              </td>

              <td>
                 REMOTE_ADDR<br />
                 REMOTE_HOST<br />
                 REMOTE_PORT<br />
                 REMOTE_USER<br />
                 REMOTE_IDENT<br />
                 REQUEST_METHOD<br />
                 SCRIPT_FILENAME<br />
                 PATH_INFO<br />
                 QUERY_STRING<br />
                 AUTH_TYPE<br />
              </td>

              <td></td>
            </tr>

            <tr>
              <th>server internals:</th> <th>date and time:</th> <th>specials:</th>
            </tr>

            <tr>
              <td>
                 DOCUMENT_ROOT<br />
                 SERVER_ADMIN<br />
                 SERVER_NAME<br />
                 SERVER_ADDR<br />
                 SERVER_PORT<br />
                 SERVER_PROTOCOL<br />
                 SERVER_SOFTWARE<br />
              </td>

              <td>
                 TIME_YEAR<br />
                 TIME_MON<br />
                 TIME_DAY<br />
                 TIME_HOUR<br />
                 TIME_MIN<br />
                 TIME_SEC<br />
                 TIME_WDAY<br />
                 TIME<br />
              </td>

              <td>
                 API_VERSION<br />
                 THE_REQUEST<br />
                 REQUEST_URI<br />
                 REQUEST_FILENAME<br />
                 IS_SUBREQ<br />
                 HTTPS<br />
                 REQUEST_SCHEME<br />
              </td>
            </tr>
          </table>

                <p>These variables all
                correspond to the similarly named HTTP
                MIME-headers, C variables of the Apache HTTP Server or
                <code>struct tm</code> fields of the Unix system.
                Most are documented elsewhere in the Manual or in
                the CGI specification.</p>

                <p>SERVER_NAME and SERVER_PORT depend on the values of
                <directive module="core">UseCanonicalName</directive> and
                <directive module="core">UseCanonicalPhysicalPort</directive>
                respectively.</p>

                <p>Those that are special to mod_rewrite include those below.</p>
        <note>
                <dl>
                  <dt><code>IS_SUBREQ</code></dt>

                  <dd>Will contain the text "true" if the request
                  currently being processed is a sub-request,
                  "false" otherwise. Sub-requests may be generated
                  by modules that need to resolve additional files
                  or URIs in order to complete their tasks.</dd>

                  <dt><code>API_VERSION</code></dt>

                  <dd>This is the version of the Apache httpd module API
                  (the internal interface between server and
                  module) in the current httpd build, as defined in
                  include/ap_mmn.h. The module API version
                  corresponds to the version of Apache httpd in use (in
                  the release version of Apache httpd 1.3.14, for
                  instance, it is 19990320:10), but is mainly of
                  interest to module authors.</dd>

                  <dt><code>THE_REQUEST</code></dt>

                  <dd>The full HTTP request line sent by the
                  browser to the server (e.g., "<code>GET
                  /index.html HTTP/1.1</code>"). This does not
                  include any additional headers sent by the
                  browser.  This value has not been unescaped
                  (decoded), unlike most other variables below.</dd>

                  <dt><code>REQUEST_URI</code></dt>

                  <dd>The path component of the requested URI,
                  such as "/index.html".  This notably excludes the
                  query string which is available as as its own variable
                  named <code>QUERY_STRING</code>.</dd>

                  <dt><code>REQUEST_FILENAME</code></dt>

                  <dd>The full local filesystem path to the file or
                  script matching the request, if this has already
                  been determined by the server at the time
                  <code>REQUEST_FILENAME</code> is referenced. Otherwise,
                  such as when used in virtual host context, the same
                  value as <code>REQUEST_URI</code>.</dd>

                  <dt><code>HTTPS</code></dt>

                  <dd>Will contain the text "on" if the connection is
                  using SSL/TLS, or "off" otherwise.  (This variable
                  can be safely used regardless of whether or not
                  <module>mod_ssl</module> is loaded).</dd>

                  <dt><code>REQUEST_SCHEME</code></dt>

                  <dd>Will contain the scheme of the request (ususally
                  "http" or "https"). This value can be influenced with
                  <directive module="core">ServerName</directive>.</dd>

                </dl>
</note>
        </li>
      </ul>

      <p>If the <em>TestString</em> has the special value <code>expr</code>, the
      <em>CondPattern</em> will be treated as a
      <a href="../expr.html">ap_expr</a>.</p>

      <p>Other things you should be aware of:</p>

      <ol>
        <li>
        <p>The variables SCRIPT_FILENAME and REQUEST_FILENAME
        contain the same value - the value of the
        <code>filename</code> field of the internal
        <code>request_rec</code> structure of the Apache HTTP Server.
        The first name is the commonly known CGI variable name
        while the second is the appropriate counterpart of
        REQUEST_URI (which contains the value of the
        <code>uri</code> field of <code>request_rec</code>).</p>
        <p>If a substitution occurred and the rewriting continues,
        the value of both variables will be updated accordingly.</p>
        <p>If used in per-server context (<em>i.e.</em>, before the
        request is mapped to the filesystem) SCRIPT_FILENAME and
        REQUEST_FILENAME cannot contain the full local filesystem
        path since the path is unknown at this stage of processing.
        Both variables will initially contain the value of REQUEST_URI
        in that case. In order to obtain the full local filesystem
        path of the request in per-server context, use an URL-based
        look-ahead <code>%{LA-U:REQUEST_FILENAME}</code> to determine
        the final value of REQUEST_FILENAME.</p></li>

        <li>
        <code>%{ENV:variable}</code>, where <em>variable</em> can be
        any environment variable, is also available.
        This is looked-up via internal
        Apache httpd structures and (if not found there) via
        <code>getenv()</code> from the Apache httpd server process.</li>

        <li>
        <code>%{SSL:variable}</code>, where <em>variable</em> is the
        name of an <a href="mod_ssl.html#envvars">SSL environment
        variable</a>, can be used whether or not
        <module>mod_ssl</module> is loaded, but will always expand to
        the empty string if it is not.  Example:
        <code>%{SSL:SSL_CIPHER_USEKEYSIZE}</code> may expand to
        <code>128</code>.</li>

        <li>
        <code>%{HTTP:header}</code>, where <em>header</em> can be
        any HTTP MIME-header name, can always be used to obtain the
        value of a header sent in the HTTP request.
        Example: <code>%{HTTP:Proxy-Connection}</code> is
        the value of the HTTP header
        ``<code>Proxy-Connection:</code>''.
        <p>If a HTTP header is used in a condition this header is added to
        the Vary header of the response in case the condition evaluates to
        to true for the request. It is <strong>not</strong> added if the
        condition evaluates to false for the request. Adding the HTTP header
        to the Vary header of the response is needed for proper caching.</p>
        <p>It has to be kept in mind that conditions follow a short circuit
        logic in the case of the '<strong><code>ornext|OR</code></strong>' flag
        so that certain conditions might not be evaluated at all.</p></li>

        <li>
        <code>%{LA-U:variable}</code> can be used for look-aheads which perform
        an internal (URL-based) sub-request to determine the final
        value of <em>variable</em>. This can be used to access
        variable for rewriting which is not available at the current
        stage, but will be set in a later phase.
        <p>For instance, to rewrite according to the
        <code>REMOTE_USER</code> variable from within the
        per-server context (<code>httpd.conf</code> file) you must
        use <code>%{LA-U:REMOTE_USER}</code> - this
        variable is set by the authorization phases, which come
        <em>after</em> the URL translation phase (during which mod_rewrite
        operates).</p>
        <p>On the other hand, because mod_rewrite implements
        its per-directory context (<code>.htaccess</code> file) via
        the Fixup phase of the API and because the authorization
        phases come <em>before</em> this phase, you just can use
        <code>%{REMOTE_USER}</code> in that context.</p></li>

        <li>
        <code>%{LA-F:variable}</code> can be used to perform an internal
        (filename-based) sub-request, to determine the final value
        of <em>variable</em>. Most of the time, this is the same as
        LA-U above.</li>
      </ol>

      <p><em>CondPattern</em> is the condition pattern,
       a regular expression which is applied to the
      current instance of the <em>TestString</em>.
      <em>TestString</em> is first evaluated, before being matched against
      <em>CondPattern</em>.</p>

      <p><em>CondPattern</em> is usually a
      <em>perl compatible regular expression</em>, but there is
      additional syntax available to perform other useful tests against
      the <em>Teststring</em>:</p>

      <ol>
        <li>You can prefix the pattern string with a
        '<code>!</code>' character (exclamation mark) to specify a
        <strong>non</strong>-matching pattern.</li>

        <li>
          You can perform lexicographical string comparisons:

          <ul>
            <li>'<strong>&lt;CondPattern</strong>' (lexicographically
            precedes)<br />
            Treats the <em>CondPattern</em> as a plain string and
            compares it lexicographically to <em>TestString</em>. True if
            <em>TestString</em> lexicographically precedes
            <em>CondPattern</em>.</li>

            <li>'<strong>&gt;CondPattern</strong>' (lexicographically
            follows)<br />
            Treats the <em>CondPattern</em> as a plain string and
            compares it lexicographically to <em>TestString</em>. True if
            <em>TestString</em> lexicographically follows
            <em>CondPattern</em>.</li>

            <li>'<strong>=CondPattern</strong>' (lexicographically
            equal)<br />
            Treats the <em>CondPattern</em> as a plain string and
            compares it lexicographically to <em>TestString</em>. True if
            <em>TestString</em> is lexicographically equal to
            <em>CondPattern</em> (the two strings are exactly
            equal, character for character). If <em>CondPattern</em>
            is <code>""</code> (two quotation marks) this
            compares <em>TestString</em> to the empty string.</li>

            <li>'<strong>&lt;=CondPattern</strong>' (lexicographically
            less than or equal to)<br />
            Treats the <em>CondPattern</em> as a plain string and
            compares it lexicographically to <em>TestString</em>. True
            if <em>TestString</em> lexicographically precedes
            <em>CondPattern</em>, or is equal to <em>CondPattern</em>
            (the two strings are equal, character for character).</li>

            <li>'<strong>&gt;=CondPattern</strong>' (lexicographically
            greater than or equal to)<br />
            Treats the <em>CondPattern</em> as a plain string and
            compares it lexicographically to <em>TestString</em>. True
            if <em>TestString</em> lexicographically follows
            <em>CondPattern</em>, or is equal to <em>CondPattern</em>
            (the two strings are equal, character for character).</li>
        </ul></li>

        <li>
          You can perform integer comparisons:
          <ul>

            <li>'<strong>-eq</strong>' (is numerically
            <strong>eq</strong>ual to)<br />
            The <em>TestString</em> is treated as an integer, and is
            numerically compared to the <em>CondPattern</em>. True if
            the two are numerically equal.</li>

            <li>'<strong>-ge</strong>' (is numerically
            <strong>g</strong>reater than or <strong>e</strong>qual to)<br />
            The <em>TestString</em> is treated as an integer, and is
            numerically compared to the <em>CondPattern</em>. True if
            the <em>TestString</em> is numerically greater than or equal
            to the <em>CondPattern</em>.</li>

             <li>'<strong>-gt</strong>' (is numerically
            <strong>g</strong>reater <strong>t</strong>han)<br />
            The <em>TestString</em> is treated as an integer, and is
            numerically compared to the <em>CondPattern</em>. True if
            the <em>TestString</em> is numerically greater than
            the <em>CondPattern</em>.</li>

            <li>'<strong>-le</strong>' (is numerically
            <strong>l</strong>ess than or <strong>e</strong>qual to)<br />
            The <em>TestString</em> is treated as an integer, and is
            numerically compared to the <em>CondPattern</em>. True if
            the <em>TestString</em> is numerically less than or equal
            to the <em>CondPattern</em>. Avoid confusion with the
            <strong>-l</strong> by using the <strong>-L</strong> or
            <strong>-h</strong> variant.</li>

             <li>'<strong>-lt</strong>' (is numerically
            <strong>l</strong>ess <strong>t</strong>han)<br />
            The <em>TestString</em> is treated as an integer, and is
            numerically compared to the <em>CondPattern</em>. True if
            the <em>TestString</em> is numerically less than
            the <em>CondPattern</em>. Avoid confusion with the
            <strong>-l</strong> by using the <strong>-L</strong> or
            <strong>-h</strong> variant.</li>

           </ul>
        </li>

        <li>You can perform various file attribute tests:
          <ul>
            <li>'<strong>-d</strong>' (is
            <strong>d</strong>irectory)<br />
             Treats the <em>TestString</em> as a pathname and tests
            whether or not it exists, and is a directory.</li>

            <li>'<strong>-f</strong>' (is regular
            <strong>f</strong>ile)<br />
             Treats the <em>TestString</em> as a pathname and tests
            whether or not it exists, and is a regular file.</li>

            <li>'<strong>-F</strong>' (is existing file, via
            subrequest)<br />
            Checks whether or not <em>TestString</em> is a valid file,
            accessible via all the server's currently-configured
            access controls for that path. This uses an internal
            subrequest to do the check, so use it with care -
            it can impact your server's performance!</li>

            <li>'<strong>-H</strong>' (is symbolic link, bash convention)<br />
            See <strong>-l</strong>.</li>

            <li>'<strong>-l</strong>' (is symbolic
            <strong>l</strong>ink)<br />
            Treats the <em>TestString</em> as a pathname and tests
            whether or not it exists, and is a symbolic link. May also
            use the bash convention of <strong>-L</strong> or
            <strong>-h</strong> if there's a possibility of confusion
            such as when using the <strong>-lt</strong> or
            <strong>-le</strong> tests.</li>

            <li>'<strong>-L</strong>' (is symbolic link, bash convention)<br />
            See <strong>-l</strong>.</li>

            <li>'<strong>-s</strong>' (is regular file, with
            <strong>s</strong>ize)<br />
            Treats the <em>TestString</em> as a pathname and tests
            whether or not it exists, and is a regular file with size greater
            than zero.</li>

            <li>'<strong>-U</strong>' (is existing URL, via
            subrequest)<br />
            Checks whether or not <em>TestString</em> is a valid URL,
            accessible via all the server's currently-configured
            access controls for that path. This uses an internal
            subrequest to do the check, so use it with care -
            it can impact your server's performance!</li>

            <li>'<strong>-x</strong>' (has e<strong>x</strong>ecutable
            permissions)<br />
            Treats the <em>TestString</em> as a pathname and tests
            whether or not it exists, and has executable permissions.
            These permissions are determined according to
            the underlying OS.</li>

          </ul>

<note><title>Note:</title>
              All of these tests can
              also be prefixed by an exclamation mark ('!') to
              negate their meaning.
</note>
        </li>

	<li>
           <p>If the <em>TestString</em> has the special value <code>expr</code>, the
           <em>CondPattern</em> will be treated as a
           <a href="../expr.html">ap_expr</a>.</p>

           <p>
            In the below example, <code>-strmatch</code> is used to
            compare the <code>REFERER</code> against the site hostname,
            to block unwanted hotlinking.
           </p>

           <example>
           RewriteCond expr "! %{HTTP_REFERER} -strmatch '*://%{HTTP_HOST}/*'"<br />
           RewriteRule ^/images - [F]
           </example>
        </li>

        <li>You can also set special flags for
      <em>CondPattern</em> by appending
        <strong><code>[</code><em>flags</em><code>]</code></strong>
      as the third argument to the <code>RewriteCond</code>
      directive, where <em>flags</em> is a comma-separated list of any of the
      following flags:

      <ul>
        <li>'<strong><code>nocase|NC</code></strong>'
        (<strong>n</strong>o <strong>c</strong>ase)<br />
        This makes the test case-insensitive - differences
        between 'A-Z' and 'a-z' are ignored, both in the
        expanded <em>TestString</em> and the <em>CondPattern</em>.
        This flag is effective only for comparisons between
        <em>TestString</em> and <em>CondPattern</em>. It has no
        effect on filesystem and subrequest checks.</li>

        <li>
          '<strong><code>ornext|OR</code></strong>'
          (<strong>or</strong> next condition)<br />
          Use this to combine rule conditions with a local OR
          instead of the implicit AND. Typical example:

<example>
<pre>
RewriteCond %{REMOTE_HOST}  ^host1  [OR]
RewriteCond %{REMOTE_HOST}  ^host2  [OR]
RewriteCond %{REMOTE_HOST}  ^host3
RewriteRule ...some special stuff for any of these hosts...
</pre>
</example>

          Without this flag you would have to write the condition/rule
          pair three times.
        </li>

        <li>'<strong><code>novary|NV</code></strong>'
        (<strong>n</strong>o <strong>v</strong>ary)<br />
        If a HTTP header is used in the condition, this flag prevents
        this header from being added to the Vary header of the response. <br />
        Using this flag might break proper caching of the response if
        the representation of this response varies on the value of this header.
        So this flag should be only used if the meaning of the Vary header
        is well understood.
        </li>
      </ul>
      </li>
     </ol>

      <p><strong>Example:</strong></p>

       <p>To rewrite the Homepage of a site according to the
        ``<code>User-Agent:</code>'' header of the request, you can
        use the following: </p>

<example>
<pre>
RewriteCond  %{HTTP_USER_AGENT}  ^Mozilla
RewriteRule  ^/$                 /homepage.max.html  [L]

RewriteCond  %{HTTP_USER_AGENT}  ^Lynx
RewriteRule  ^/$                 /homepage.min.html  [L]

RewriteRule  ^/$                 /homepage.std.html  [L]
</pre>
</example>

        <p>Explanation: If you use a browser which identifies itself
        as 'Mozilla' (including Netscape Navigator, Mozilla etc), then you
        get the max homepage (which could include frames, or other special
        features).
        If you use the Lynx browser (which is terminal-based), then
        you get the min homepage (which could be a version designed for
        easy, text-only browsing).
        If neither of these conditions apply (you use any other browser,
        or your browser identifies itself as something non-standard), you get
        the std (standard) homepage.</p>

</usage>

</directivesynopsis>

<directivesynopsis>
<name>RewriteRule</name>
<description>Defines rules for the rewriting engine</description>
<syntax>RewriteRule
      <em>Pattern</em> <em>Substitution</em> [<em>flags</em>]</syntax>
<contextlist><context>server config</context><context>virtual host</context>
<context>directory</context><context>.htaccess</context></contextlist>
<override>FileInfo</override>

<usage>
      <p>The <directive>RewriteRule</directive> directive is the real
      rewriting workhorse. The directive can occur more than once,
      with each instance defining a single rewrite rule. The
      order in which these rules are defined is important - this is the order
      in which they will be applied at run-time.</p>

      <p><a id="patterns" name="patterns"><em>Pattern</em></a> is
      a perl compatible <a id="regexp" name="regexp">regular
      expression</a>. On the first RewriteRule it is applied to the (%-decoded)
      <a href="./directive-dict.html#Syntax">URL-path</a> of the request;
      subsequent patterns are applied to the output of the last matched
      RewriteRule.</p>

<note><title><a id="what_is_matched" name="what_is_matched">What is matched?</a></title>
      <p>In <directive module="core">VirtualHost</directive> context,
      The <em>Pattern</em> will initially be matched against the part of the
      URL after the hostname and port, and before the query string (e.g. "/app1/index.html").</p>

      <p>In <directive module="core">Directory</directive> and htaccess context,
      the <em>Pattern</em> will initially be matched against the
      <em>filesystem</em> path, after removing the prefix that lead the server
      to the current <directive>RewriteRule</directive> (e.g. "app1/index.html"
      or "index.html" depending on where the directives are defined).</p>

      <p>If you wish to match against the hostname, port, or query string, use a
      <directive module="mod_rewrite">RewriteCond</directive> with the
      <code>%{HTTP_HOST}</code>, <code>%{SERVER_PORT}</code>, or
      <code>%{QUERY_STRING}</code> variables respectively.</p>

</note>

<note><title>Per-directory Rewrites</title>
<ul>
<li>The rewrite engine may be used in <a
href="../howto/htaccess.html">.htaccess</a> files and in <directive type="section"
module="core">Directory</directive> sections, with some additional
complexity.</li>

<li>To enable the rewrite engine in this context, you need to set
"<code>RewriteEngine On</code>" <strong>and</strong>
"<code>Options FollowSymLinks</code>" must be enabled. If your
administrator has disabled override of <code>FollowSymLinks</code> for
a user's directory, then you cannot use the rewrite engine. This
restriction is required for security reasons.</li>

<li>When using the rewrite engine in <code>.htaccess</code> files the
per-directory prefix (which always is the same for a specific
directory) is automatically <em>removed</em> for the RewriteRule pattern matching
and automatically <em>added</em> after any relative (not starting with a
slash or protocol name) substitution encounters the end of a rule set.
See the <directive module="mod_rewrite">RewriteBase</directive>
directive for more information regarding what prefix will be added back to
relative substitions.</li>

<li> If you wish to match against the full URL-path in a per-directory
(htaccess) RewriteRule, use the <code>%{REQUEST_URI}</code> variable in
a <directive>RewriteCond</directive>.</li>

<li>The removed prefix always ends with a slash, meaning the matching occurs against a string which
<em>never</em> has a leading slash.  Therefore, a <em>Pattern</em> with <code>^/</code> never
matches in per-directory context.</li>

<li>Although rewrite rules are syntactically permitted in <directive
type="section" module="core">Location</directive> and <directive
type="section" module="core">Files</directive> sections, this
should never be necessary and is unsupported.</li>
</ul>
</note>

      <p>For some hints on <glossary ref="regex">regular
      expressions</glossary>, see
      the <a href="../rewrite/intro.html#regex">mod_rewrite
      Introduction</a>.</p>

      <p>In mod_rewrite, the NOT character
      ('<code>!</code>') is also available as a possible pattern
      prefix. This enables you to negate a pattern; to say, for instance:
      ``<em>if the current URL does <strong>NOT</strong> match this
      pattern</em>''. This can be used for exceptional cases, where
      it is easier to match the negative pattern, or as a last
      default rule.</p>

<note><title>Note</title>
When using the NOT character to negate a pattern, you cannot include
grouped wildcard parts in that pattern. This is because, when the
pattern does NOT match (ie, the negation matches), there are no
contents for the groups. Thus, if negated patterns are used, you
cannot use <code>$N</code> in the substitution string!
</note>

      <p>The <a id="rhs" name="rhs"><em>Substitution</em></a> of a
      rewrite rule is the string that replaces the original URL-path that
      was matched by <em>Pattern</em>.  The <em>Substitution</em> may
      be a:</p>

      <dl>

        <dt>file-system path</dt>

        <dd>Designates the location on the file-system of the resource
        to be delivered to the client.</dd>

        <dt>URL-path</dt>

        <dd>A <directive
        module="core">DocumentRoot</directive>-relative path to the
        resource to be served. Note that <module>mod_rewrite</module>
        tries to guess whether you have specified a file-system path
        or a URL-path by checking to see if the first segment of the
        path exists at the root of the file-system. For example, if
        you specify a <em>Substitution</em> string of
        <code>/www/file.html</code>, then this will be treated as a
        URL-path <em>unless</em> a directory named <code>www</code>
        exists at the root or your file-system, in which case it will
        be treated as a file-system path. If you wish other
        URL-mapping directives (such as <directive
        module="mod_alias">Alias</directive>) to be applied to the
        resulting URL-path, use the <code>[PT]</code> flag as
        described below.</dd>

        <dt>Absolute URL</dt>

        <dd>If an absolute URL is specified,
        <module>mod_rewrite</module> checks to see whether the
        hostname matches the current host. If it does, the scheme and
        hostname are stripped out and the resulting path is treated as
        a URL-path. Otherwise, an external redirect is performed for
        the given URL. To force an external redirect back to the
        current host, see the <code>[R]</code> flag below.</dd>

        <dt><code>-</code> (dash)</dt>

        <dd>A dash indicates that no substitution should be performed
        (the existing path is passed through untouched). This is used
        when a flag (see below) needs to be applied without changing
        the path.</dd>

      </dl>

      <p>In addition to plain text, the <em>Substition</em> string can include</p>

      <ol>
        <li>back-references (<code>$N</code>) to the RewriteRule
        pattern</li>

        <li>back-references (<code>%N</code>) to the last matched
        RewriteCond pattern</li>

        <li>server-variables as in rule condition test-strings
        (<code>%{VARNAME}</code>)</li>

        <li><a href="#mapfunc">mapping-function</a> calls
        (<code>${mapname:key|default}</code>)</li>
      </ol>

      <p>Back-references are identifiers of the form
      <code>$</code><strong>N</strong>
      (<strong>N</strong>=0..9), which will be replaced
      by the contents of the <strong>N</strong>th group of the
      matched <em>Pattern</em>. The server-variables are the same
      as for the <em>TestString</em> of a <code>RewriteCond</code>
      directive. The mapping-functions come from the
      <code>RewriteMap</code> directive and are explained there.
      These three types of variables are expanded in the order above.</p>

      <p>Rewrite rules are applied to the results of previous rewrite
      rules, in the order in which they are defined
      in the config file. The URI or file path (see <a
      href="#what_is_matched">"What is matched?"</a>, above) is <strong>completely
      replaced</strong> by the <em>Substitution</em> and the
      rewriting process continues until all rules have been applied,
      or it is explicitly terminated by an
      <a href="../rewrite/flags.html#flag_l"><code><strong>L</strong></code> flag</a>,
      or other flag which implies immediate termination, such as
      <code><strong>END</strong></code> or
      <code><strong>F</strong></code>.</p>

     <note><title>Modifying the Query String</title>
      <p>By default, the query string is passed through unchanged. You
      can, however, create URLs in the substitution string containing
      a query string part. Simply use a question mark inside the
      substitution string to indicate that the following text should
      be re-injected into the query string. When you want to erase an
      existing query string, end the substitution string with just a
      question mark. To combine new and old query strings, use the
      <code>[QSA]</code> flag.</p>
     </note>

      <p>Additionally you can set special <a name="rewriteflags"
      id="rewriteflags">actions</a> to be performed by
      appending <strong><code>[</code><em>flags</em><code>]</code></strong>
      as the third argument to the <code>RewriteRule</code>
      directive. <em>Flags</em> is a comma-separated list, surround by square
      brackets, of any of the flags in the following table. More
      details, and examples, for each flag, are available in the <a
      href="../rewrite/flags.html">Rewrite Flags document</a>.</p>

    <table border="1">
    <tr><th>Flag and syntax</th>
        <th>Function</th>
    </tr>
    <tr>
        <td>B</td>
        <td>Escape non-alphanumeric characters <em>before</em> applying
        the transformation. <em><a
        href="../rewrite/flags.html#flag_b">details ...</a></em></td>
    </tr>
    <tr>
        <td>chain|C</td>
        <td>Rule is chained to the following rule. If the rule fails,
        the rule(s) chained to it will be skipped. <em><a
        href="../rewrite/flags.html#flag_c">details ...</a></em></td>
    </tr>
    <tr>
        <td>cookie|CO=<em>NAME</em>:<em>VAL</em></td>
        <td>Sets a cookie in the client browser. Full syntax is:
        CO=<em>NAME</em>:<em>VAL</em>:<em>domain</em>[:<em>lifetime</em>[:<em>path</em>[:<em>secure</em>[:<em>httponly</em>]]]] <em><a href="../rewrite/flags.html#flag_co">details ...</a></em>
        </td>
    </tr>
    <tr>
        <td>discardpath|DPI</td>
        <td>Causes the PATH_INFO portion of the rewritten URI to be
        discarded. <em><a href="../rewrite/flags.html#flag_dpi">details
        ...</a></em></td>
    </tr>
    <tr>
        <td>env|E=[!]<em>VAR</em>[:<em>VAL</em>]</td>
        <td>Causes an environment variable <em>VAR</em> to be set (to the
        value <em>VAL</em> if provided). The form !<em>VAR</em> causes
        the environment variable <em>VAR</em> to be unset.<em><a
        href="../rewrite/flags.html#flag_e">details ...</a></em></td>
    </tr>
    <tr>
        <td>forbidden|F</td>
        <td>Returns a 403 FORBIDDEN response to the client browser.
        <em><a href="../rewrite/flags.html#flag_f">details ...</a></em></td>
    </tr>
    <tr>
        <td>gone|G</td>
        <td>Returns a 410 GONE response to the client browser. <em><a
        href="../rewrite/flags.html#flag_g">details ...</a></em></td>
    </tr>
    <tr>
        <td>Handler|H=<em>Content-handler</em></td>
        <td>Causes the resulting URI to be sent to the specified
        <em>Content-handler</em> for processing. <em><a
        href="../rewrite/flags.html#flag_h">details ...</a></em></td>
    </tr>
    <tr>
        <td>last|L</td>
        <td>Stop the rewriting process immediately and don't apply any
        more rules. Especially note caveats for per-directory and
        .htaccess context (see also the END flag). <em><a
        href="../rewrite/flags.html#flag_l">details ...</a></em></td>
    </tr>
    <tr>
        <td>next|N</td>
        <td>Re-run the rewriting process, starting again with the first
        rule, using the result of the ruleset so far as a starting
        point. <em><a href="../rewrite/flags.html#flag_n">details
        ...</a></em></td>
    </tr>
    <tr>
        <td>nocase|NC</td>
        <td>Makes the pattern pattern comparison case-insensitive.
        <em><a href="../rewrite/flags.html#flag_nc">details ...</a></em></td>
    </tr>
    <tr>
        <td>noescape|NE</td>
        <td>Prevent mod_rewrite from applying hexcode escaping of
        special characters in the result of the rewrite. <em><a
        href="../rewrite/flags.html#flag_ne">details ...</a></em></td>
    </tr>
    <tr>
        <td>nosubreq|NS</td>
        <td>Causes a rule to be skipped if the current request is an
        internal sub-request. <em><a
        href="../rewrite/flags.html#flag_ns">details ...</a></em></td>
    </tr>
    <tr>
        <td>proxy|P</td>
        <td>Force the substitution URL to be internally sent as a proxy
        request. <em><a href="../rewrite/flags.html#flag_p">details
        ...</a></em></td>
    </tr>
    <tr>
        <td>passthrough|PT</td>
        <td>Forces the resulting URI to be passed back to the URL
        mapping engine for processing of other URI-to-filename
        translators, such as <code>Alias</code> or
        <code>Redirect</code>. <em><a
        href="../rewrite/flags.html#flag_pt">details ...</a></em></td>
    </tr>
    <tr>
        <td>qsappend|QSA</td>
        <td>Appends any query string created in the rewrite target to
        any query string that was in the original request URL. <em><a
        href="../rewrite/flags.html#flag_qsa">details ...</a></em></td>
    </tr>
    <tr>
        <td>qsdiscard|QSD</td>
        <td>Discard any query string attached to the incoming URI.
        <em><a href="../rewrite/flags.html#flag_qsd">details
        ...</a></em></td>
    </tr>
    <tr>
        <td>redirect|R[=<em>code</em>]</td>
        <td>Forces an external redirect, optionally with the specified
        HTTP status code. <em><a
        href="../rewrite/flags.html#flag_r">details ...</a></em>
        </td>
    </tr>
    <tr>
        <td>END</td>
        <td>Stop the rewriting process immediately and don't apply any
        more rules. Also prevents further execution of rewrite rules
        in per-directory and .htaccess context. (Available in 2.3.9 and later)
        <em><a href="../rewrite/flags.html#flag_l">details ...</a></em></td>
    </tr>
    <tr>
        <td>skip|S=<em>num</em></td>
        <td>Tells the rewriting engine to skip the next <em>num</em>
        rules if the current rule matches. <em><a
        href="../rewrite/flags.html#flag_s">details ...</a></em></td>
    </tr>
    <tr>
        <td>type|T=<em>MIME-type</em></td>
        <td>Force the <glossary>MIME-type</glossary> of the target file
        to be the specified type. <em><a
        href="../rewrite/flags.html#flag_t">details ...</a></em></td>
    </tr>
    </table>

<note><title>Home directory expansion</title>
<p> When the substitution string begins with a string
resembling "/~user" (via explicit text or backreferences), mod_rewrite performs
home directory expansion independent of the presence or configuration
of <module>mod_userdir</module>.</p>

<p> This expansion does not occur when the <em>PT</em>
flag is used on the <directive module="mod_rewrite">RewriteRule</directive>
directive.</p>
</note>


     <p>Here are all possible substitution combinations and their
      meanings:</p>

      <p><strong>Inside per-server configuration
      (<code>httpd.conf</code>)<br />
       for request ``<code>GET
      /somepath/pathinfo</code>'':</strong><br />
      </p>

<table border="1">
<tr>
<th>Given Rule</th>
<th>Resulting Substitution</th>
</tr>

<tr>
<td>^/somepath(.*) otherpath$1</td>
<td>invalid, not supported</td>
</tr>

<tr>
<td>^/somepath(.*) otherpath$1  [R]</td>
<td>invalid, not supported</td>
</tr>

<tr>
<td>^/somepath(.*) otherpath$1  [P]</td>
<td>invalid, not supported</td>
</tr>

<tr>
<td>^/somepath(.*) /otherpath$1</td>
<td>/otherpath/pathinfo</td>
</tr>

<tr>
<td>^/somepath(.*) /otherpath$1 [R]</td>
<td>http://thishost/otherpath/pathinfo via external redirection</td>
</tr>

<tr>
<td>^/somepath(.*) /otherpath$1 [P]</td>
<td>doesn't make sense, not supported</td>
</tr>

<tr>
<td>^/somepath(.*) http://thishost/otherpath$1</td>
<td>/otherpath/pathinfo</td>
</tr>

<tr>
<td>^/somepath(.*) http://thishost/otherpath$1 [R]</td>
<td>http://thishost/otherpath/pathinfo via external redirection</td>
</tr>

<tr>
<td>^/somepath(.*) http://thishost/otherpath$1 [P]</td>
<td>doesn't make sense, not supported</td>
</tr>

<tr>
<td>^/somepath(.*) http://otherhost/otherpath$1</td>
<td>http://otherhost/otherpath/pathinfo via external redirection</td>
</tr>

<tr>
<td>^/somepath(.*) http://otherhost/otherpath$1 [R]</td>
<td>http://otherhost/otherpath/pathinfo via external redirection (the [R] flag is redundant)</td>
</tr>

<tr>
<td>^/somepath(.*) http://otherhost/otherpath$1 [P]</td>
<td>http://otherhost/otherpath/pathinfo via internal proxy</td>
</tr>
</table>

      <p><strong>Inside per-directory configuration for
      <code>/somepath</code><br />
       (<code>/physical/path/to/somepath/.htacccess</code>, with
      <code>RewriteBase /somepath</code>)<br />
       for request ``<code>GET
      /somepath/localpath/pathinfo</code>'':</strong><br />
     </p>

<table border="1">

<tr>
<th>Given Rule</th>
<th>Resulting Substitution</th>
</tr>

<tr>
<td>^localpath(.*) otherpath$1</td>
<td>/somepath/otherpath/pathinfo</td>
</tr>

<tr>
<td>^localpath(.*) otherpath$1  [R]</td>
<td>http://thishost/somepath/otherpath/pathinfo via external
redirection</td>
</tr>

<tr>
<td>^localpath(.*) otherpath$1  [P]</td>
<td>doesn't make sense, not supported</td>
</tr>

<tr>
<td>^localpath(.*) /otherpath$1</td>
<td>/otherpath/pathinfo</td>
</tr>

<tr>
<td>^localpath(.*) /otherpath$1 [R]</td>
<td>http://thishost/otherpath/pathinfo via external redirection</td>
</tr>

<tr>
<td>^localpath(.*) /otherpath$1 [P]</td>
<td>doesn't make sense, not supported</td>
</tr>

<tr>
<td>^localpath(.*) http://thishost/otherpath$1</td>
<td>/otherpath/pathinfo</td>
</tr>

<tr>
<td>^localpath(.*) http://thishost/otherpath$1 [R]</td>
<td>http://thishost/otherpath/pathinfo via external redirection</td>
</tr>

<tr>
<td>^localpath(.*) http://thishost/otherpath$1 [P]</td>
<td>doesn't make sense, not supported</td>
</tr>

<tr>
<td>^localpath(.*) http://otherhost/otherpath$1</td>
<td>http://otherhost/otherpath/pathinfo via external redirection</td>
</tr>

<tr>
<td>^localpath(.*) http://otherhost/otherpath$1 [R]</td>
<td>http://otherhost/otherpath/pathinfo via external redirection (the [R] flag is redundant)</td>
</tr>

<tr>
<td>^localpath(.*) http://otherhost/otherpath$1 [P]</td>
<td>http://otherhost/otherpath/pathinfo via internal proxy</td>
</tr>

</table>

  </usage>
 </directivesynopsis>
</modulesynopsis>