# `httpd_util` [🔗](https://github.com/erlang/otp/blob/master/lib/inets/src/http_server/httpd_util.erl#L23) Miscellaneous utility functions to be used when implementing Erlang web server API modules. This module provides the Erlang web server API module programmer with miscellaneous utility functions. > #### Note {: .info } > > Note the module is only recommended for using with httpd - for other cases it > should be considered as deprecated. [](){: #convert_request_date } ### See also `m:httpd` # `convert_request_date` ```elixir -spec convert_request_date(DateString) -> ErlDate | bad_date when DateString :: string(), ErlDate :: calendar:datetime(). ``` `convert_request_date/1` converts `DateString` to the Erlang date format. `DateString` must be in one of the three date formats defined in [RFC 2616](http://www.ietf.org/rfc/rfc2616.txt). # `create_etag` ```elixir -spec create_etag(FileInfo) -> Etag when FileInfo :: file:file_info(), Etag :: string(). ``` `create_etag/1` calculates the Etag for a file from its size and time for last modification. `FileInfo` is a record defined in `kernel/include/file.hrl`. # `day` ```elixir -spec day(NthDayOfWeek) -> DayOfWeek when NthDayOfWeek :: 1..7, DayOfWeek :: string(). ``` `day/1` converts the day of the week (`NthDayOfWeek`) from an integer (1-7) to an abbreviated string, that is: 1 = "Mon", 2 = "Tue", ..., 7 = "Sat". # `lookup` ```elixir -spec lookup(EtsTable, Key) -> Result when EtsTable :: ets:table(), Key :: term(), Result :: term() | undefined. ``` # `lookup` ```elixir -spec lookup(EtsTable, Key, Undefined) -> Result when EtsTable :: ets:table(), Key :: term(), Undefined :: term(), Result :: term() | Undefined. ``` `lookup` extracts `{Key, Value}` tuples from `ETSTable` and returns the `Value` associated with `Key`. If `ETSTable` is of type `bag`, only the first `Value` associated with `Key` is returned. `lookup/2` returns `undefined` and `lookup/3` returns `Undefined` if no `Value` is found. # `lookup_mime` ```elixir -spec lookup_mime(ConfigDB, Suffix) -> MimeType when ConfigDB :: ets:tid(), Suffix :: string(), MimeType :: string() | undefined. ``` # `lookup_mime` ```elixir -spec lookup_mime(ConfigDB, Suffix, Undefined) -> MimeType when ConfigDB :: ets:tid(), Suffix :: string(), Undefined :: term(), MimeType :: string() | Undefined. ``` `lookup_mime` returns the MIME type associated with a specific file suffix as specified in the file `mime.types` (located in the config directory). # `lookup_mime_default` ```elixir -spec lookup_mime_default(ConfigDB, Suffix) -> MimeType when ConfigDB :: ets:tid(), Suffix :: string(), MimeType :: string() | undefined. ``` # `lookup_mime_default` ```elixir -spec lookup_mime_default(ConfigDB, Suffix, Undefined) -> MimeType when ConfigDB :: ets:tid(), Suffix :: string(), Undefined :: term(), MimeType :: string() | Undefined. ``` `lookup_mime_default` returns the MIME type associated with a specific file suffix as specified in the `mime.types` file (located in the config directory). If no appropriate association is found, the value of `DefaultType` is returned. # `message` ```elixir -spec message(StatusCode, PhraseArgs, ConfigDB) -> Message when StatusCode :: 301 | 304 | 400 | 401 | 403 | 404 | 408 | 412 | 413 | 414 | 500 | 501 | 503 | 504, PhraseArgs :: term(), ConfigDB :: ets:tid(), Message :: string(). ``` `message/3` returns an informative HTTP 1.1 status string in HTML. Each `StatusCode` requires a specific `PhraseArgs`: - **`301`** - `t:string/0`: A URL pointing at the new document position. - **`400 | 401 | 500`** - `none` (no `PhraseArgs`). - **`403 | 404`** - `t:string/0`: A `Request-URI` as described in [RFC 2616](http://www.ietf.org/rfc/rfc2616.txt). - **`501`** - `{Method, RequestURI, HTTPVersion}`: The HTTP `Method`, `Request-URI`, and `HTTP-Version` as defined in RFC 2616. - **`504`** - `t:string/0`: A string describing why the service was unavailable. # `month` ```elixir -spec month(NthMonth) -> Month when NthMonth :: 1..12, Month :: string(). ``` `month/1` converts the month `NthMonth` as an integer (1-12) to an abbreviated string, that is: 1 = "Jan", 2 = "Feb", ..., 12 = "Dec". # `multi_lookup` ```elixir -spec multi_lookup(EtsTable, Key) -> Result when EtsTable :: ets:tid(), Key :: term(), Result :: list() | [term()]. ``` `multi_lookup` extracts all `{Key, Value}` tuples from an `ETSTable` and returns _all_ `Values` associated with `Key` in a list. # `reason_phrase` ```elixir -spec reason_phrase(StatusCode) -> Description when StatusCode :: 100 | 101 | 102 | 200 | 201 | 202 | 203 | 204 | 205 | 206 | 207 | 226 | 300 | 301 | 302 | 303 | 304 | 305 | 306 | 307 | 308 | 400 | 401 | 402 | 403 | 404 | 405 | 406 | 407 | 408 | 409 | 410 | 411 | 412 | 413 | 414 | 415 | 416 | 417 | 422 | 423 | 424 | 425 | 426 | 500 | 501 | 502 | 503 | 504 | 505 | 507, Description :: string(). ``` `reason_phrase` returns `Description` of an HTTP 1.1 `StatusCode`, for example, 200 is "OK" and 201 is "Created". For more information, see [RFC 2616](http://www.ietf.org/rfc/rfc2616.txt). # `rfc1123_date` ```elixir -spec rfc1123_date() -> RFC1123Date when RFC1123Date :: string(). ``` # `rfc1123_date` ```elixir -spec rfc1123_date(LocalTime) -> RFC1123Date when LocalTime :: calendar:datetime() | undefined, RFC1123Date :: string() | undefined. ``` `rfc1123_date/0` returns the current date in RFC 1123 format. `rfc_date/1` converts the date in the Erlang format to the RFC 1123 date format. # `split` ```elixir -spec split(String, RegExp, N) -> SplitRes when String :: string(), RegExp :: string(), N :: non_neg_integer(), SplitRes :: {ok, FieldList} | {error, term()}, FieldList :: [string()]. ``` `split/3` splits `String` in `N` chunks using `RegExp`. `split/3` is equivalent to `re:split/3` with the exception that `N` defines the maximum number of fields in `FieldList`. # `split_path` ```elixir -spec split_path(URIString) -> {Path, QueryStringOrPathInfo} when URIString :: string(), Path :: string(), QueryStringOrPathInfo :: string(). ``` `split_path/1` splits `RequestLine` in a file reference (`Path`), and a `QueryString` or a `PathInfo` string as specified in [RFC 2616](http://www.ietf.org/rfc/rfc2616.txt). A `QueryString` is isolated from `Path` with a question mark (`?`) and `PathInfo` with a slash (/). In the case of a `QueryString`, everything before `?` is a `Path` and everything after `?` is a `QueryString`. In the case of a `PathInfo`, `RequestLine` is scanned from left-to-right on the hunt for longest possible `Path` being a file or a directory. Everything after the longest possible `Path`, isolated with a `/`, is regarded as `PathInfo` # `split_script_path` ```elixir -spec split_script_path(URIString) -> Split when URIString :: string(), Split :: not_a_script | {Path, {PathInfo, QueryString}} | {Path, []}, Path :: string(), QueryString :: string(), PathInfo :: string(). ``` `split_script_path/1` is equivalent to `split_path/1` with one exception. If the longest possible path is not a regular, accessible, and executable file, then `not_a_script` is returned. --- *Consult [api-reference.md](api-reference.md) for complete listing*