<?xml version="1.0" encoding="utf-8" ?> <!DOCTYPE erlref SYSTEM "erlref.dtd"> <erlref> <header> <copyright> <year>1997</year><year>2016</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. </legalnotice> <title>httpd_util</title> <prepared>Joakim Grebenö</prepared> <docno></docno> <date>1997-10-14</date> <rev>2.2</rev> <file>httpd_util.sgml</file> </header> <module>httpd_util</module> <modulesummary>Miscellaneous utility functions to be used when implementing Erlang web server API modules.</modulesummary> <description> <p>This module provides the Erlang web server API module programmer with miscellaneous utility functions.</p> <marker id="convert_request_date"></marker> </description> <funcs> <func> <name>convert_request_date(DateString) -> ErlDate|bad_date</name> <fsummary>Converts the date to the Erlang date format.</fsummary> <type> <v>DateString = string()</v> <v>ErlDate = {{Year,Month,Date},{Hour,Min,Sec}}</v> <v>Year = Month = Date = Hour = Min = Sec = integer()</v> </type> <desc> <p><c>convert_request_date/1</c> converts <c>DateString</c> to the Erlang date format. <c>DateString</c> must be in one of the three date formats defined in <url href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</url>.</p> </desc> </func> <func> <name>create_etag(FileInfo) -> Etag</name> <fsummary>Calculates the Etag for a file.</fsummary> <type> <v>FileInfo = file_info()</v> <v>Etag = string()</v> </type> <desc> <p><c>create_etag/1</c> calculates the Etag for a file from its size and time for last modification. <c>FileInfo</c> is a record defined in <c>kernel/include/file.hrl</c>.</p> </desc> </func> <func> <name>day(NthDayOfWeek) -> DayOfWeek</name> <fsummary>Converts the day of the week (integer [1-7]) to an abbreviated string.</fsummary> <type> <v>NthDayOfWeek = 1-7</v> <v>DayOfWeek = string()</v> </type> <desc> <p><c>day/1</c> converts the day of the week (<c>NthDayOfWeek</c>) from an integer (1-7) to an abbreviated string, that is:</p> <p>1 = "Mon", 2 = "Tue", ..., 7 = "Sat".</p> </desc> </func> <func> <name>decode_hex(HexValue) -> DecValue</name> <fsummary>Converts a hexadecimal value into its decimal equivalent.</fsummary> <type> <v>HexValue = DecValue = string()</v> </type> <desc> <p>Converts the hexadecimal value <c>HexValue</c> into its decimal equivalent (<c>DecValue</c>).</p> </desc> </func> <func> <name>flatlength(NestedList) -> Size</name> <fsummary>Computes the size of a possibly nested list.</fsummary> <type> <v>NestedList = list()</v> <v>Size = integer()</v> </type> <desc> <p><c>flatlength/1</c> computes the size of the possibly nested list <c>NestedList</c>, which can contain binaries.</p> </desc> </func> <func> <name>hexlist_to_integer(HexString) -> Number</name> <fsummary>Converts a hexadecimal string to an integer.</fsummary> <type> <v>Number = integer()</v> <v>HexString = string()</v> </type> <desc> <p><c>hexlist_to_integer</c> converts the hexadecimal value of <c>HexString</c> to an integer.</p> </desc> </func> <func> <name>integer_to_hexlist(Number) -> HexString</name> <fsummary>Converts an integer to a hexadecimal string.</fsummary> <type> <v>Number = integer()</v> <v>HexString = string()</v> </type> <desc> <p><c>integer_to_hexlist/1</c> returns a string representing <c>Number</c> in a hexadecimal form.</p> </desc> </func> <func> <name>lookup(ETSTable,Key) -> Result</name> <name>lookup(ETSTable,Key,Undefined) -> Result</name> <fsummary>Extracts the first value associated with a <c>Key</c> in an ETS table.</fsummary> <type> <v>ETSTable = ets_table()</v> <v>Key = term()</v> <v>Result = term() | undefined | Undefined</v> <v>Undefined = term()</v> </type> <desc> <p><c>lookup</c> extracts <c>{Key,Value}</c> tuples from <c>ETSTable</c> and returns the <c>Value</c> associated with <c>Key</c>. If <c>ETSTable</c> is of type <c>bag</c>, only the first <c>Value</c> associated with <c>Key</c> is returned. <c>lookup/2</c> returns <c>undefined</c> and <c>lookup/3</c> returns <c>Undefined</c> if no <c>Value</c> is found.</p> </desc> </func> <func> <name>lookup_mime(ConfigDB,Suffix)</name> <name>lookup_mime(ConfigDB,Suffix,Undefined) -> MimeType</name> <fsummary>Returns the MIME type associated with a specific file suffix.</fsummary> <type> <v>ConfigDB = ets_table()</v> <v>Suffix = string()</v> <v>MimeType = string() | undefined | Undefined</v> <v>Undefined = term()</v> </type> <desc> <p><c>lookup_mime</c> returns the MIME type associated with a specific file suffix as specified in the file <c>mime.types</c> (located in the <path unix="$SERVER_ROOT/conf/mime.types" windows="%SERVER_ROOT%\conf\mime.types"> config directory</path>).</p> </desc> </func> <func> <name>lookup_mime_default(ConfigDB,Suffix)</name> <name>lookup_mime_default(ConfigDB,Suffix,Undefined) -> MimeType</name> <fsummary>Returns the MIME type associated with a specific file suffix or the value of the DefaultType.</fsummary> <type> <v>ConfigDB = ets_table()</v> <v>Suffix = string()</v> <v>MimeType = string() | undefined | Undefined</v> <v>Undefined = term()</v> </type> <desc> <p><c>lookup_mime_default</c> returns the MIME type associated with a specific file suffix as specified in the <c>mime.types</c> file (located in the <path unix="$SERVER_ROOT/conf/mime.types" windows="%SERVER_ROOT%\conf\mime.types"> config directory</path>). If no appropriate association is found, the value of <c>DefaultType</c> is returned.</p> </desc> </func> <func> <name>message(StatusCode,PhraseArgs,ConfigDB) -> Message</name> <fsummary>Returns an informative HTTP 1.1 status string in HTML.</fsummary> <type> <v>StatusCode = 301 | 400 | 403 | 404 | 500 | 501 | 504</v> <v>PhraseArgs = term()</v> <v>ConfigDB = ets_table</v> <v>Message = string()</v> </type> <desc> <p><c>message/3</c> returns an informative HTTP 1.1 status string in HTML. Each <c>StatusCode</c> requires a specific <c>PhraseArgs</c>: </p> <taglist> <tag><c>301</c></tag> <item><p><c>string()</c>: A URL pointing at the new document position.</p></item> <tag><c>400 | 401 | 500</c></tag> <item><p><c>none</c> (no <c>PhraseArgs</c>).</p></item> <tag><c>403 | 404</c></tag> <item><p><c>string()</c>: A <c>Request-URI</c> as described in <url href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</url>.</p> </item> <tag><c>501</c></tag> <item><p><c>{Method,RequestURI,HTTPVersion}</c>: The HTTP <c>Method</c>, <c>Request-URI</c>, and <c>HTTP-Version</c> as defined in RFC 2616.</p></item> <tag><c>504</c></tag> <item><p><c>string()</c>: A string describing why the service was unavailable.</p></item> </taglist> </desc> </func> <func> <name>month(NthMonth) -> Month</name> <fsummary>Converts the month as an integer (1-12) to an abbreviated string.</fsummary> <type> <v>NthMonth = 1-12</v> <v>Month = string()</v> </type> <desc> <p><c>month/1</c> converts the month <c>NthMonth</c> as an integer (1-12) to an abbreviated string, that is: </p> <p>1 = "Jan", 2 = "Feb", ..., 12 = "Dec".</p> </desc> </func> <func> <name>multi_lookup(ETSTable,Key) -> Result</name> <fsummary>Extracts the values associated with a key in an ETS table.</fsummary> <type> <v>ETSTable = ets_table()</v> <v>Key = term()</v> <v>Result = [term()]</v> </type> <desc> <p><c>multi_lookup</c> extracts all <c>{Key,Value}</c> tuples from an <c>ETSTable</c> and returns <em>all</em> <c>Values</c> associated with <c>Key</c> in a list.</p> </desc> </func> <func> <name>reason_phrase(StatusCode) -> Description</name> <fsummary>Returns the description of an HTTP 1.1 status code.</fsummary> <type> <v>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</v> <v>Description = string()</v> </type> <desc> <p><c>reason_phrase</c> returns <c>Description</c> of an HTTP 1.1 <c>StatusCode</c>, for example, 200 is "OK" and 201 is "Created". For more information, see <url href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</url>.</p> </desc> </func> <func> <name>rfc1123_date() -> RFC1123Date</name> <name>rfc1123_date({{YYYY,MM,DD},{Hour,Min,Sec}}) -> RFC1123Date</name> <fsummary>Returns the current date in RFC 1123 format.</fsummary> <type> <v>YYYY = MM = DD = Hour = Min = Sec = integer()</v> <v>RFC1123Date = string()</v> </type> <desc> <p><c>rfc1123_date/0</c> returns the current date in RFC 1123 format. <c>rfc_date/1</c> converts the date in the Erlang format to the RFC 1123 date format.</p> </desc> </func> <func> <name>split(String,RegExp,N) -> SplitRes</name> <fsummary>Splits a string in N chunks using a regular expression.</fsummary> <type> <v>String = RegExp = string()</v> <v>SplitRes = {ok, FieldList} | {error, errordesc()}</v> <v>Fieldlist = [string()]</v> <v>N = integer</v> </type> <desc> <p><c>split/3</c> splits <c>String</c> in <c>N</c> chunks using <c>RegExp</c>. <c>split/3</c> is equivalent to <c>regexp:split/2</c> with the exception that <c>N</c> defines the maximum number of fields in <c>FieldList</c>.</p> </desc> </func> <func> <name>split_script_path(RequestLine) -> Splitted</name> <fsummary>Splits a <c>RequestLine</c> in a file reference to an executable, and a <c>QueryString</c> or a <c>PathInfo</c>string.</fsummary> <type> <v>RequestLine = string()</v> <v>Splitted = not_a_script | {Path, PathInfo, QueryString}</v> <v>Path = QueryString = PathInfo = string()</v> </type> <desc> <p><c>split_script_path/1</c> is equivalent to <c>split_path/1</c> with one exception. If the longest possible path is not a regular, accessible, and executable file, then <c>not_a_script</c> is returned.</p> </desc> </func> <func> <name>split_path(RequestLine) -> {Path,QueryStringOrPathInfo}</name> <fsummary>Splits a <c>RequestLine</c> in a file reference, and a <c>QueryString</c> or a <c>PathInfo</c> string.</fsummary> <type> <v>RequestLine = Path = QueryStringOrPathInfo = string()</v> </type> <desc> <p><c>split_path/1</c> splits <c>RequestLine</c> in a file reference (<c>Path</c>), and a <c>QueryString</c> or a <c>PathInfo</c> string as specified in <url href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</url>. A <c>QueryString</c> is isolated from <c>Path</c> with a question mark (<c>?</c>) and <c>PathInfo</c> with a slash (/). In the case of a <c>QueryString</c>, everything before <c>?</c> is a <c>Path</c> and everything after <c>?</c> is a <c>QueryString</c>. In the case of a <c>PathInfo</c>, <c>RequestLine</c> is scanned from left-to-right on the hunt for longest possible <c>Path</c> being a file or a directory. Everything after the longest possible <c>Path</c>, isolated with a <c>/</c>, is regarded as <c>PathInfo</c>. The resulting <c>Path</c> is decoded using <c>decode_hex/1</c> before delivery.</p> </desc> </func> <func> <name>strip(String) -> Stripped</name> <fsummary>Returns <c>String</c> where the leading and trailing space tabs are removed.</fsummary> <type> <v>String = Stripped = string()</v> </type> <desc> <p><c>strip/1</c> removes any leading or trailing linear white space from the string. Linear white space is to be read as horizontal tab or space.</p> </desc> </func> <func> <name>suffix(FileName) -> Suffix</name> <fsummary>Extracts the file suffix from a given filename.</fsummary> <type> <v>FileName = Suffix = string()</v> </type> <desc> <p><c>suffix/1</c> is equivalent to <c>filename:extension/1</c> with the exception that <c>Suffix</c> is returned without a leading dot (<c>.</c>).</p> </desc> </func> </funcs> <section> <title>SEE ALSO</title> <p><seealso marker="httpd">httpd(3)</seealso></p> </section> </erlref>