6 dirplex - Physical directory handler for ashd(7)
10 *dirplex* [*-hN*] [*-c* 'CONFIG'] 'DIR'
15 The *dirplex* handler maps URLs into physical files or directories,
16 and, having found a matching file or directory, it performs various
17 kinds of pattern-matching against its physical name to determine what
18 handler to call in order to serve the request. The mapping procedure
19 and pattern matching are described below.
21 Having found a handler to serve a file or directory with, *dirplex*
22 adds the `X-Ash-File` header to the request with a path to the
23 physical file, before passing the request on to the handler.
25 *dirplex* is a persistent handler, as defined in *ashd*(7).
32 Print a brief help message to standard output and exit.
36 Do not read the global configuration file `dirplex.rc`.
40 Read an extra configuration file. If 'CONFIG' contains any
41 slashes, it is opened by that exact name. Otherwise, it is
42 searched for in the same way as the global configuration file
43 (see CONFIGURATION below).
48 Mapping URLs into physical files is an iterative procedure, each step
49 looking in one single physical directory, starting with 'DIR'. For
50 each step, a path element is stripped off the beginning of the rest
51 string and examined, the path element being either the leading part of
52 the rest string up until (but not including) the first slash, or the
53 entire rest string if it contains no slashes. If the rest string is
54 empty, the directory being examined is considered the result of the
55 mapping. Otherwise, any escape sequences in the path element under
56 consideration are unescaped before examining it.
58 If the path element names a directory in the current directory, the
59 procedure continues in that directory, unless there is nothing left of
60 the rest string, in which case *dirplex* responds with a HTTP 301
61 redirect to the same URL, but ending with a slash. Otherwise, the
62 remaining rest string begins with a slash, which is stripped off
63 before continuing. If the path element names a file, that file is
64 considered the result of the mapping (even if the rest string has not
67 If the path element does not name anything in the directory under
68 consideration, but contains no dots, then the directory is searched
69 for a file whose name before the first dot matches the path
70 element. If there is such a file, it is considered the result of the
73 If the result of the mapping procedure is a directory, it is checked
74 for the presence of a filed named by the *index-file* configuration
75 directive (see CONFIGURATION below). If there is such a file, it is
76 considered the final result instead of the directory itself. If the
77 index file name contains no dots and there is no exact match, then,
78 again, the directory is searched for a file whose name before the
79 first dot matches the index file name.
81 See also 404 RESPONSES below.
86 Configuration in *dirplex* comes from several sources. When *dirplex*
87 starts, unless the *-N* option is given, it tries to find a global
88 configuration file named `dirplex.rc`. It looks in `$HOME/.ashd/etc`,
89 and then in all directories named by the *PATH* environment variable,
90 appended with `../etc/ashd`. For example, then, if *PATH* is
91 `/usr/local/bin:/bin:/usr/bin`, the directories `$HOME/.ashd/etc`,
92 `/usr/local/etc/ashd`, `/etc/ashd` and `/usr/etc/ashd` are searched
93 for `dirplex.rc`, in that order. Only the first file found is used,
94 should there exist several.
96 If the *-c* option is given to *dirplex*, it too specifies a
97 configuration file to load. If the name given contains any slashes, it
98 is opened by that exact name. Otherwise, it is searched for in the
99 same manner as the global configuration file.
101 In addition, all directories traversed by *dirplex* when mapping a URL
102 into a physical file may contain a file called `.htrc`, which may
103 specify extra configuration options for all files in and beneath that
106 `.htrc` files are checked periodically and reread if changed. The
107 global configuration file and any file named by the *-c* option,
108 however, are never reexamined.
110 When using the configuration files for deciding what to do with a
111 found file, they are examined in order of their "distance" from that
112 file. `.htrc` files found in the directory or directories containing
113 the file are considered "closest" to the file under consideration,
114 followed by any configuration file named by the *-c* option, followed
115 by the global configuration file.
117 Each configuration file is a sequence of configuration stanzas, each
118 stanza being an unindented starting line, followed by zero or more
119 indented follow-up lines adding options to the stanza. The starting
120 line of a stanza is referred to as a "configuration directive"
121 below. Each line is a sequence of whitespace-separated words. A word
122 may contain whitespace if such whitespace is escaped, either by
123 enclosing the word in double quotes, or by escaping individual
124 whitespace characters with a preceding backslash. Backslash quoting
125 may also be used to treat double quotes or another backslash literally
126 as part of the word. Empty lines are ignored, and lines whose first
127 character after leading whitespace is a hash character (`#`) are
128 treated as comments and ignored.
130 The following configuration directives are recognized:
132 *include* ['FILENAME'...]::
134 Read the named files and act as if their contents stood in
135 place of the *include* stanza. A 'FILENAME' may be a glob
136 pattern, in which case all matching files are used, sorted by
137 their filenames. If a 'FILENAME' is a relative path, it is
138 treated relative to the directory containing the file from
139 which the *include* stanza was read, even if the inclusion has
140 been nested. Inclusions may be nested to any level.
142 *index-file* ['FILENAME'...]::
144 The given 'FILENAMEs' are used for finding index files (see
145 URL-TO-FILE MAPPING above). Specifying *index-file* overrides
146 entirely any previous specification in a more distant
147 configuration file, rather than adding to it. Zero 'FILENAMEs'
148 may be given to turn off index file searching completely. The
149 *index-file* directive accepts no follow-up lines.
153 Declares a named, persistent request handler (see *ashd*(7)
154 for a more detailed description of persistent handlers). It
155 must contain exactly one follow-up line, *exec* 'PROGRAM'
156 ['ARGS'...], specifying the program to execute and the
157 arguments to pass it. If given in a `.htrc` file, the program
158 will be started in the same directory as the `.htrc` file
159 itself. The *child* stanza itself serves as the identity of
160 the forked process -- only one child process will be forked
161 per stanza, and if that child process exits, it will be
162 restarted the next time the stanza would be used. If a `.htrc`
163 file containing *child* stanzas is reloaded, any currently
164 running children are reused for *child* stanzas in the new
165 file with matching names (even if the *exec* line has
170 Declares a named, transient request handler (see *ashd*(7) for
171 a more detailed description of transient handlers). It must
172 contain exactly one follow-up line, *exec* 'PROGRAM'
173 ['ARGS'...], specifying the program to execute and the
174 arguments to pass it. In addition to the specified arguments,
175 the HTTP method, raw URL and the rest string will be appended
176 as described in *ashd*(7). If given in a `.htrc` file, the
177 program will be started in the same directory as the `.htrc`
182 Specifies a filename pattern-matching rule. The
183 pattern-matching procedure and the follow-up lines accepted by
184 this stanza are described below, under MATCHING.
186 *capture* 'HANDLER' ['FLAGS']::
188 Only meaningful in `.htrc` files. If a *capture* directive is
189 specified, then the URL-to-file mapping procedure as described
190 above is aborted as soon as the directory containing the
191 `.htrc` file is encountered. The request is passed, with any
192 remaining rest string, to the specified 'HANDLER', which must
193 be a named request handler specified either in the same
194 `.htrc` file or elsewhere. The *capture* directive accepts no
195 follow-up lines. Note that the `X-Ash-File` header is not
196 added to requests passed via *capture* directives. If 'FLAGS'
197 contain the character `R`, this *capture* directive will be
198 ignored if it is in the root directory that *dirplex* serves.
203 When a file or directory has been found by the mapping procedure (see
204 URL-TO-FILE MAPPING above), the name of the physical file is examined
205 to determine a request handler to pass the request to. Note that only
206 the physical file name is ever considered; any logical request
207 parameters such as the request URL or the rest string are entirely
210 To match a file, any *match* stanzas specified by any `.htrc` file or
211 in the global configuration files are searched in order of their
212 "distance" (see CONFIGURATION above) from the actual file. Which
213 *match* stanzas are considered depends on the type of the file being
214 matched: if an ordinary file is being matched, only *match* stanzas
215 without any 'TYPE' parameter are considered, while if it is a
216 directory, only those with type 'TYPE' parameter specified as
217 *directory* are considered. 'TYPE' can also take the value *notfound*,
218 described below under 404 RESPONSES.
220 A *match* stanza must contain at least one follow-up line specifying
221 match rules. All rules must match for the stanza as a whole to match.
222 The following rules are recognized:
224 *filename* 'PATTERN'...::
226 Matches if the name of the file under consideration matches
227 any of the 'PATTERNs'. A 'PATTERN' is an ordinary glob
228 pattern, such as `*.php`. See *fnmatch*(3) for more
231 *pathname* 'PATTERN'...::
233 Matches if the entire path of the file under consideration
234 matches any of the 'PATTERNs'. A 'PATTERN' is an ordinary glob
235 pattern, except that slashes are not matched by wildcards. See
236 *fnmatch*(3) for more information. If a *pathname* rule is
237 specified in a `.htrc` file, the path will be examined as
238 relative to the directory containing the `.htrc` file, rather
239 than to the root directory being served.
243 Matches if and only if no *match* stanza without a *default*
244 rule matches (in any configuration file).
248 Valid only in `.htrc` files, *local* matches if and only if
249 the file under consideration resides in the same directory as
250 the containing `.htrc` file.
252 In addition to the rules, a *match* stanza must contain exactly one
253 follow-up line specifying the action to take if it matches. The
254 following actions are recognized:
256 *handler* 'HANDLER'::
258 'HANDLER' must be a named handler (see CONFIGURATION
259 above). The named handler is searched for not only in the same
260 configuration file as the *match* stanza, but in all
261 configuration files that are valid for the file under
262 consideration, in order of distance. As such, a more deeply
263 nested `.htrc` file may override the specified handler without
264 having to specify any new *match* stanzas.
266 *fork* 'PROGRAM' ['ARGS'...]::
268 Run a transient handler for this file, as if it were specified
269 by a *fchild* stanza. This action exists mostly for
272 A *match* stanza may also contain any number of the following,
275 *set* 'HEADER' 'VALUE'::
277 If the *match* stanza is selected as the match for a file, the
278 named HTTP 'HEADER' in the request is set to 'VALUE' before
279 passing the request on to the specified handler.
281 *xset* 'HEADER' 'VALUE'::
283 *xset* does exactly the same thing as *set*, except that
284 'HEADER' is automatically prepended with the `X-Ash-`
285 prefix. The intention is only to make configuration files
286 look nicer in this very common case.
291 A HTTP 404 response is sent to the client if
293 * The mapping procedure fails to find a matching physical file;
294 * A path element is encountered during mapping which, after URL
295 unescaping, either begins with a dot or contains slashes;
296 * The mapping procedure finds a file which is neither a directory nor
297 a regular file (or a symbolic link to any of the same);
298 * An empty, non-final path element is encountered during mapping; or
299 * The mapping procedure results in a file which is not matched by any
302 By default, *dirplex* will send a built-in 404 response, but there are
303 two ways to customize the response:
305 First, *match* stanzas with the type *notfound* will be matched
306 against any request that would result in a 404 error. The filename for
307 such matching is that of the last succesfully found component, which
308 may be a directory, for example in case a name component could not be
309 found in the real filesystem; or a file, for example in case a file
310 was found, but not matched by any *match* stanzas.
312 Otherwise, any request that would result in a 404 response but is
313 matched by no *notfound* stanza is instead passed to a default handler
314 named `.notfound`, which is handled internally in *dirplex* by
315 default, but may be overridden just as any other handler may be in a
316 `.htrc` file or by global configuration. Note, however, that any
317 request not matched by a *notfound* stanza will not have the
318 `X-Ash-File` header added to it.
320 The built-in `.notfound` handler can also be used in *match* or
321 *capture* stanzas (for example, to restrict access to certain files or
327 The *sendfile*(1) program can be used to serve HTML files as follows.
334 filename *.html *.htm
335 xset content-type text/html
339 Assuming the PHP CGI interpreter is installed on the system, PHP
340 scripts can be used with the following configuration, using the
341 *callcgi*(1) program.
344 # To use plain CGI, which uses more resources per handled request,
345 # but less static resources:
347 exec callcgi -p php-cgi
349 # To use FastCGI, which keeps PHP running at all times, but uses less
350 # resources per handled request:
352 exec callfcgi multifscgi 5 php-cgi
359 If there is a directory without an index file, a file listing can be
360 automatically generated by the *htls*(1) program as follows.
368 The following configuration can be placed in a `.htrc` file in order
369 to dedicate the directory containing that file to some external SCGI
370 script engine. Note that *callscgi*, and therefore the script engine
371 itself, is started in the same directory, so that arbitrary code
372 modules or data files can be put directly in that directory and be
377 exec callscgi scgi-wsgi -p . foo
384 Fredrik Tolf <fredrik@dolda2000.com>
Dolda2000 GitWeb / ashd.git / blob