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 all directories
89 named by the *PATH* environment variable, appended with
90 `../etc/ashd`. For example, then, if *PATH* is
91 `/usr/local/bin:/bin:/usr/bin`, the directories `/usr/local/etc/ashd`,
92 `/etc/ashd` and `/usr/etc/ashd` are searched for `dirplex.rc`, in that
93 order. Only the first file found is used, should there exist several.
95 If the *-c* option is given to *dirplex*, it too specifies a
96 configuration file to load. If the name given contains any slashes, it
97 is opened by that exact name. Otherwise, it is searched for in the
98 same manner as the global configuration file.
100 In addition, all directories traversed by *dirplex* when mapping a URL
101 into a physical file may contain a file called `.htrc`, which may
102 specify extra configuration options for all files in and beneath that
105 `.htrc` files are checked periodically and reread if changed. The
106 global configuration file and any file named by the *-c* option,
107 however, are never reexamined.
109 When using the configuration files for deciding what to do with a
110 found file, they are examined in order of their "distance" from that
111 file. `.htrc` files found in the directory or directories containing
112 the file are considered "closest" to the file under consideration,
113 followed by any configuration file named by the *-c* option, followed
114 by the global configuration file.
116 Each configuration file is a sequence of configuration stanzas, each
117 stanza being an unindented starting line, followed by zero or more
118 indented follow-up lines adding options to the stanza. The starting
119 line of a stanza is referred to as a "configuration directive"
120 below. Each line is a sequence of whitespace-separated words. A word
121 may contain whitespace if such whitespace is escaped, either by
122 enclosing the word in double quotes, or by escaping individual
123 whitespace characters with a preceding backslash. Backslash quoting
124 may also be used to treat double quotes or another backslash literally
125 as part of the word. Empty lines are ignored, and lines whose first
126 character after leading whitespace is a hash character (`#`) are
127 treated as comments and ignored.
129 The follow configuration directives are recognized:
131 *include* ['FILENAME'...]::
133 Read the named files and act as if their contents stood in
134 place of the *include* stanza. A 'FILENAME' may be a glob
135 pattern, in which case all matching files are used, sorted by
136 their filenames. If a 'FILENAME' is a relative path, it is
137 treated relative to the directory containing the file from
138 which the *include* stanza was read, even if the inclusion has
139 been nested. Inclusions may be nested to any level.
141 *index-file* ['FILENAME'...]::
143 The given 'FILENAMEs' are used for finding index files (see
144 URL-TO-FILE MAPPING above). Specifying *index-file* overrides
145 entirely any previous specification in a more distant
146 configuration file, rather than adding to it. Zero 'FILENAMEs'
147 may be given to turn off index file searching completely. The
148 *index-file* directive accepts no follow-up lines.
152 Declares a named, persistent request handler (see *ashd*(7)
153 for a more detailed description of persistent handlers). It
154 must contain exactly one follow-up line, *exec* 'PROGRAM'
155 ['ARGS'...], specifying the program to execute and the
156 arguments to pass it. If given in a `.htrc` file, the program
157 will be started in the same directory as the `.htrc` file
158 itself. The *child* stanza itself serves as the identity of
159 the forked process -- only one child process will be forked
160 per stanza, and if that child process exits, it will be
161 restarted the next time the stanza would be used. If a `.htrc`
162 file containing *child* stanzas is reloaded, any currently
163 running children are reused for *child* stanzas in the new
164 file with matching names (even if the *exec* line has
169 Declares a named, transient request handler (see *ashd*(7) for
170 a more detailed description of transient handlers). It must
171 contain exactly one follow-up line, *exec* 'PROGRAM'
172 ['ARGS'...], specifying the program to execute and the
173 arguments to pass it. In addition to the specified arguments,
174 the HTTP method, raw URL and the rest string will be appended
175 as described in *ashd*(7). If given in a `.htrc` file, the
176 program will be started in the same directory as the `.htrc`
179 *match* [*directory*]::
181 Specifies a filename pattern-matching rule. The
182 pattern-matching procedure and the follow-up lines accepted by
183 this stanza are described below, under MATCHING.
185 *capture* 'HANDLER'::
187 Only meaningful in `.htrc` files. If a *capture* directive is
188 specified, then the URL-to-file mapping procedure as described
189 above is aborted as soon as the directory containing the
190 `.htrc` file is encountered. The request is passed, with any
191 remaining rest string, to the specified 'HANDLER', which must
192 by a named request handler specified either in the same
193 `.htrc` file or elsewhere. The *capture* directive accepts no
194 follow-up lines. Note that the `X-Ash-File` header is not
195 added to requests passed via *capture* directives.
200 When a file or directory has been found by the mapping procedure (see
201 URL-TO-FILE MAPPING above), the name of the physical file is examined
202 to determine a request handler to pass the request to. Note that only
203 the physical file name is ever considered; any logical request
204 parameters such as the request URL or the rest string are entirely
207 To match a file, any *match* stanzas specified by any `.htrc` file or
208 in the global configuration files are searched in order of their
209 "distance" (see CONFIGURATION above) from the actual file. If it is a
210 directory which is being considered, only *match* stanzas with the
211 *directory* parameter are considered; otherwise, if it is a file, only
212 *match* stanzas without the *directory* parameter are considered.
214 A *match* stanza must contain at least one follow-up line specifying
215 match rules. All rules must match for the stanza as a whole to match.
216 The following rules are recognized:
218 *filename* 'PATTERN'...::
220 Matches if the name of the file under consideration matches
221 any of the 'PATTERNs'. A 'PATTERN' is an ordinary glob
222 pattern, such as `*.php`. See *fnmatch*(3) for more
225 *pathname* 'PATTERN'...::
227 Matches if the entire path of the file under consideration
228 matches any of the 'PATTERNs'. A 'PATTERN' is an ordinary glob
229 pattern, except that slashes are not matched by wildcards. See
230 *fnmatch*(3) for more information. If a *pathname* rule is
231 specified in a `.htrc` file, the path will be examined as
232 relative to the directory containing the `.htrc` file, rather
233 than to the root directory being served.
237 Matches if and only if no *match* stanza without a *default*
238 rule matches (in any configuration file).
242 Valid only in `.htrc` files, *local* matches if and only if
243 the file under consideration resides in the same directory as
244 the containing `.htrc` file.
246 In addition to the rules, a *match* stanza must contain exactly one
247 follow-up line specifying the action to take if it matches. The
248 following actions are recognized:
250 *handler* 'HANDLER'::
252 'HANDLER' must be a named handler (see CONFIGURATION
253 above). The named handler is searched for not only in the same
254 configuration file as the *match* stanza, but in all
255 configuration files that are valid for the file under
256 consideration, in order of distance. As such, a more deeply
257 nested `.htrc` file may override the specified handler without
258 having to specify any new *match* stanzas.
260 *fork* 'PROGRAM' ['ARGS'...]::
262 Run a transient handler for this file, as if it were specified
263 by a *fchild* stanza. This action exists mostly for
266 A *match* stanza may also contain any number of the following,
269 *set* 'HEADER' 'VALUE'::
271 If the *match* stanza is selected as the match for a file, the
272 named HTTP 'HEADER' in the request is set to 'VALUE' before
273 passing the request on to the specified handler.
275 *xset* 'HEADER' 'VALUE'::
277 *xset* does exactly the same thing as *set*, except the
278 'HEADER' is automatically prepended with the `X-Ash-`
279 prefix. The intention is only to make configuration files
280 look nicer in this very common case.
285 A HTTP 404 response is sent to the client if
287 * The mapping procedure fails to find a matching physical file;
288 * A path element is encountered during mapping which, after URL
289 unescaping, either begins with a dot or contains slashes;
290 * The mapping procedure finds a file which is neither a directory nor
292 * An empty, non-final path element is encountered during mapping; or
293 * The mapping procedure results in a file which is not matched by any
296 By default, *dirplex* will send a built-in 404 response, but any
297 `.htrc` file or global configuration may define a request handler
298 named `.notfound` to customize the behavior. Note that, unlike
299 successful requests, such a handler will not be passed the
302 The built-in `.notfound` handler can also be used in *match* or
303 *capture* stanzas (for example, to restrict access to certain files or
309 The *sendfile*(1) program can be used to serve HTML files as follows.
317 xset content-type text/html
321 Assuming the PHP CGI interpreter is installed on the system, PHP
322 scripts can be used with the following configuration, using the
323 *callcgi*(1) program.
326 # To use plain CGI, which uses more resources per handled request,
327 # but less static resources:
329 exec callcgi -p php-cgi
331 # To use FastCGI, which keeps PHP running at all times, but uses less
332 # resources per handled request:
334 exec callfcgi multifscgi 5 php-cgi
341 If there is a directory without an index file, a file listing can be
342 automatically generated by the *htls*(1) program as follows.
350 The following configuration can be placed in a `.htrc` file in order
351 to dedicate the directory containing that file to some external SCGI
352 script engine. Note that *callscgi*, and therefore the script engine
353 itself, is started in the directory itself, so that arbitrary code
354 modules or data files can be put directly in that directory and easily
359 exec callscgi scgi-wsgi -p . foo
366 Fredrik Tolf <fredrik@dolda2000.com>
Dolda2000 GitWeb / ashd.git / blob