httpd_util

MODULE

httpd_util

MODULE SUMMARY

Miscellaneous utility functions to be used when implementing EWSAPI modules.

DESCRIPTION

This module provides the EWSAPI module programmer with miscellaneous utility functions.

The current implementation of EWSAPI is under review and feedback is welcomed.

EXPORTS

decode_base64(Base64String) -> ASCIIString

Types:
Base64String = ASCIIString = string()

decode_base64/1 converts Base64String to the plain ascii string (ASCIIString). The string "BAD!" is returned if Base64String is not base64 encoded. Read more about base64 encoding in RFC 1521.

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".

encode_base64(ASCIIString) -> Base64String

Types:
ASCIIString = string()
Base64String = string()

encode_base64 encodes a plain ascii string to a Base64 encoded string. See RFC 1521 for a description of Base64 encoding.

header(StatusCode,Date)
header(StatusCode,MimeType,Date) -> HTTPHeader

Types:
StatusCode = integer()
Date = rfc1123_date()
MimeType = string()

header returns a HTTP 1.0 header string. The StatusCode is one of the status codes defined in RFC 1945 and the Date string is RFC 1123 compliant. (See rfc1123_date/0).

flatlength(NestedList) -> Size

Types:
NestedList = list()
Size = integer()

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

key1search(TupleList,Key)
key1search(TupleList,Key,Undefined) -> Result

Types:
TupleList = [tuple()]
Key = term()
Result = term() | undefined | Undefined
Undefined = term()

key1search searches the TupleList for a tuple whose first element is Key. key1search/2 returns undefined and key1search/3 returns Undefined if no tuple is found.

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 (UNIX: $SERVER_ROOT/conf/mime.types, Windows: %SERVER_ROOT%\conf\mime.types)).

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 (UNIX: $SERVER_ROOT/conf/mime.types, Windows: %SERVER_ROOT%\conf\mime.types)). 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 1.0 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 1945.

501

{Method,RequestURI,HTTPVersion}: The HTTP Method, Request-URI and HTTP-Version as defined in RFC 1945.

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 all Values associated with the Key in a list.

reason_phrase(StatusCode) -> Description

Types:
StatusCode = 200 | 201 | 204 | 301 | 302 | 304 | 400 | 401 | 403 | 404 | 500 | 501 | 502 | 504
Description = string()

reason_phrase returns the Description of an HTTP 1.0 StatusCode, for example 200 is "OK" and 201 is "Created". Read RFC 1945 for further information.

rfc1123_date() -> RFC1123Date

Types:
RFC1123Date = string()

rfc1123_date/0 returns the current date in RFC 1123 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 1945. 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.

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 (.).

to_lower(String) -> ConvertedString

Types:
String = ConvertedString = string()

to_lower/1 converts upper-case letters to lower-case.

to_upper(String) -> ConvertedString

Types:
String = ConvertedString = string()

to_upper/1 converts lower-case letters to upper-case.

SEE ALSO

httpd(3)

AUTHORS

Joakim Grebenö - support@erlang.ericsson.se
Mattias Nilsson - support@erlang.ericsson.se