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 that is defined in the 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

decode_hex(HexValue) -> DecValue

  • HexValue = DecValue = string()

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

day(NthDayOfWeek) -> DayOfWeek

  • NthDayOfWeek = 1-7
  • DayOfWeek = string()

day/1 converts the day of the week (NthDayOfWeek) as an integer (1-7) to an abbreviated string, that is:

1 = "Mon", 2 = "Tue", ..., 7 = "Sat".

flatlength(NestedList) -> Size

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

flatlength/1 computes the size of the possibly nested list NestedList. Which may contain binaries.

hexlist_to_integer(HexString) -> Number

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

hexlist_to_integer Convert the Hexadecimal value of HexString to an integer.

integer_to_hexlist(Number) -> HexString

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

integer_to_hexlist/1 Returns a string that represents the 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 mime.types file (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 can be 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 allValues associated with the 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 the Description of an HTTP 1.1 StatusCode, for example 200 is "OK" and 201 is "Created". Read RFC 2616 for further information.

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

split_path(RequestLine) -> {Path,QueryStringOrPathInfo}

  • RequestLine = Path = QueryStringOrPathInfo = string()

split_path/1 splits the RequestLine in a file reference (Path) and a QueryString or a PathInfo string as specified in RFC 2616. A QueryString is isolated from the Path with a question mark (?) and PathInfo with a slash (/). In the case of a QueryString, everything before the ? is a Path and everything after a QueryString. In the case of a PathInfo the 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 should be read as horizontal tab or space.

suffix(FileName) -> Suffix

  • FileName = Suffix = string()

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

SEE ALSO

httpd(3)

View Functions