httpd_util

(inets)

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.

Functions


convert_request_date(DateString) -> ErlDate|bad_date

  • DateString = string()
  • ErlDate = {{Year,Month,Date},{Hour,Min,Sec}}
  • Year = Month = Date = Hour = Min = Sec = integer()

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.

create_etag(FileInfo) -> Etag

  • FileInfo = 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(NthDayOfWeek) -> DayOfWeek

  • 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".

decode_hex(HexValue) -> DecValue

  • HexValue = DecValue = string()

Converts the hexadecimal value HexValue into its decimal equivalent (DecValue).

flatlength(NestedList) -> Size

  • NestedList = list()
  • Size = integer()

flatlength/1 computes the size of the possibly nested list NestedList, which can contain binaries.

hexlist_to_integer(HexString) -> Number

  • Number = integer()
  • HexString = string()

hexlist_to_integer converts the hexadecimal value of HexString to an integer.

integer_to_hexlist(Number) -> HexString

  • Number = integer()
  • HexString = string()

integer_to_hexlist/1 returns a string representing Number in a hexadecimal form.

lookup(ETSTable,Key) -> Result

lookup(ETSTable,Key,Undefined) -> Result

  • ETSTable = ets_table()
  • Key = term()
  • Result = term() | undefined | Undefined
  • Undefined = term()

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(ConfigDB,Suffix)

lookup_mime(ConfigDB,Suffix,Undefined) -> MimeType

  • ConfigDB = ets_table()
  • Suffix = string()
  • MimeType = string() | undefined | Undefined
  • Undefined = term()

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(ConfigDB,Suffix)

lookup_mime_default(ConfigDB,Suffix,Undefined) -> MimeType

  • ConfigDB = ets_table()
  • Suffix = string()
  • MimeType = string() | undefined | Undefined
  • Undefined = term()

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(StatusCode,PhraseArgs,ConfigDB) -> Message

  • StatusCode = 301 | 400 | 403 | 404 | 500 | 501 | 504
  • PhraseArgs = term()
  • ConfigDB = ets_table
  • Message = string()

message/3 returns an informative HTTP 1.1 status string in HTML. Each StatusCode requires a specific PhraseArgs:

301

string(): A URL pointing at the new document position.

400 | 401 | 500

none (no PhraseArgs).

403 | 404

string(): A Request-URI as described in RFC 2616.

501

{Method,RequestURI,HTTPVersion}: The HTTP Method, Request-URI, and HTTP-Version as defined in RFC 2616.

504

string(): A string describing why the service was unavailable.

month(NthMonth) -> Month

  • 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(ETSTable,Key) -> Result

  • ETSTable = ets_table()
  • Key = term()
  • Result = [term()]

multi_lookup extracts all {Key,Value} tuples from an ETSTable and returns all Values associated with Key in a list.

reason_phrase(StatusCode) -> Description

  • StatusCode = 100| 200 | 201 | 202 | 204 | 205 | 206 | 300 | 301 | 302 | 303 | 304 | 400 | 401 | 402 | 403 | 404 | 405 | 406 | 410 411 | 412 | 413 | 414 415 | 416 | 417 | 500 | 501 | 502 | 503 | 504 | 505
  • 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.

rfc1123_date() -> RFC1123Date

rfc1123_date({{YYYY,MM,DD},{Hour,Min,Sec}}) -> RFC1123Date

  • YYYY = MM = DD = Hour = Min = Sec = integer()
  • RFC1123Date = string()

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(String,RegExp,N) -> SplitRes

  • String = RegExp = string()
  • SplitRes = {ok, FieldList} | {error, errordesc()}
  • Fieldlist = [string()]
  • N = integer

split/3 splits String in N chunks using RegExp. split/3 is equivalent to regexp:split/2 with the exception that N defines the maximum number of fields in FieldList.

split_script_path(RequestLine) -> Splitted

  • RequestLine = string()
  • Splitted = not_a_script | {Path, PathInfo, QueryString}
  • Path = QueryString = 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.

split_path(RequestLine) -> {Path,QueryStringOrPathInfo}

  • RequestLine = Path = QueryStringOrPathInfo = string()

split_path/1 splits RequestLine in a file reference (Path), and a QueryString or a PathInfo string as specified in RFC 2616. 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. The resulting Path is decoded using decode_hex/1 before delivery.

strip(String) -> Stripped

  • String = Stripped = string()

strip/1 removes any leading or trailing linear white space from the string. Linear white space is to be read as horizontal tab or space.

suffix(FileName) -> Suffix

  • FileName = Suffix = string()

suffix/1 is equivalent to filename:extension/1 with the exception that Suffix is returned without a leading dot (.).

SEE ALSO

httpd(3)