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httpd_util

MODULE

httpd_util

MODULE SUMMARY

Miscellaneous utility functions to be used when implementing Erlang Web server API modules.

DESCRIPTION

This module provides the Erlang Web Server API module programmer with miscellaneous utility functions.

EXPORTS

convert_request_date(DateString) -> ErlDate|bad_date

Types:

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

Types:

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

Types:

HexValue = DecValue = string()

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

day(NthDayOfWeek) -> DayOfWeek

Types:

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

Types:

NestedList = list()
Size = integer()

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

hexlist_to_integer(HexString) -> Number

Types:

Number = integer()
HexString = string()

hexlist_to_integer Convert the Hexadecimal value of HexString to an integer.

integer_to_hexlist(Number) -> HexString

Types:

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

Types:

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

Types:

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

Types:

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

Types:

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

Types:

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

Types:

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

Types:

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

Types:

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

Types:

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

Types:

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}

Types:

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

Types:

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

Types:

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