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/*!
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 * content-disposition
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 * Copyright(c) 2014-2017 Douglas Christopher Wilson
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 * MIT Licensed
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 */
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'use strict'
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/**
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 * Module exports.
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 * @public
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 */
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module.exports = contentDisposition
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module.exports.parse = parse
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/**
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 * Module dependencies.
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 * @private
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 */
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var basename = require('path').basename
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var Buffer = require('safe-buffer').Buffer
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/**
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 * RegExp to match non attr-char, *after* encodeURIComponent (i.e. not including "%")
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 * @private
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 */
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var ENCODE_URL_ATTR_CHAR_REGEXP = /[\x00-\x20"'()*,/:;<=>?@[\\\]{}\x7f]/g // eslint-disable-line no-control-regex
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/**
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 * RegExp to match percent encoding escape.
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 * @private
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 */
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var HEX_ESCAPE_REGEXP = /%[0-9A-Fa-f]{2}/
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var HEX_ESCAPE_REPLACE_REGEXP = /%([0-9A-Fa-f]{2})/g
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/**
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 * RegExp to match non-latin1 characters.
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 * @private
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 */
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var NON_LATIN1_REGEXP = /[^\x20-\x7e\xa0-\xff]/g
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/**
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 * RegExp to match quoted-pair in RFC 2616
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 *
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 * quoted-pair = "\" CHAR
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 * CHAR        = <any US-ASCII character (octets 0 - 127)>
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 * @private
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 */
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var QESC_REGEXP = /\\([\u0000-\u007f])/g // eslint-disable-line no-control-regex
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/**
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 * RegExp to match chars that must be quoted-pair in RFC 2616
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 * @private
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 */
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var QUOTE_REGEXP = /([\\"])/g
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/**
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 * RegExp for various RFC 2616 grammar
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 *
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 * parameter     = token "=" ( token | quoted-string )
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 * token         = 1*<any CHAR except CTLs or separators>
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 * separators    = "(" | ")" | "<" | ">" | "@"
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 *               | "," | ";" | ":" | "\" | <">
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 *               | "/" | "[" | "]" | "?" | "="
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 *               | "{" | "}" | SP | HT
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 * quoted-string = ( <"> *(qdtext | quoted-pair ) <"> )
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 * qdtext        = <any TEXT except <">>
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 * quoted-pair   = "\" CHAR
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 * CHAR          = <any US-ASCII character (octets 0 - 127)>
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 * TEXT          = <any OCTET except CTLs, but including LWS>
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 * LWS           = [CRLF] 1*( SP | HT )
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 * CRLF          = CR LF
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 * CR            = <US-ASCII CR, carriage return (13)>
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 * LF            = <US-ASCII LF, linefeed (10)>
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 * SP            = <US-ASCII SP, space (32)>
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 * HT            = <US-ASCII HT, horizontal-tab (9)>
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 * CTL           = <any US-ASCII control character (octets 0 - 31) and DEL (127)>
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 * OCTET         = <any 8-bit sequence of data>
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 * @private
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 */
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var PARAM_REGEXP = /;[\x09\x20]*([!#$%&'*+.0-9A-Z^_`a-z|~-]+)[\x09\x20]*=[\x09\x20]*("(?:[\x20!\x23-\x5b\x5d-\x7e\x80-\xff]|\\[\x20-\x7e])*"|[!#$%&'*+.0-9A-Z^_`a-z|~-]+)[\x09\x20]*/g // eslint-disable-line no-control-regex
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var TEXT_REGEXP = /^[\x20-\x7e\x80-\xff]+$/
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var TOKEN_REGEXP = /^[!#$%&'*+.0-9A-Z^_`a-z|~-]+$/
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/**
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 * RegExp for various RFC 5987 grammar
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 *
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 * ext-value     = charset  "'" [ language ] "'" value-chars
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 * charset       = "UTF-8" / "ISO-8859-1" / mime-charset
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 * mime-charset  = 1*mime-charsetc
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 * mime-charsetc = ALPHA / DIGIT
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 *               / "!" / "#" / "$" / "%" / "&"
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 *               / "+" / "-" / "^" / "_" / "`"
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 *               / "{" / "}" / "~"
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 * language      = ( 2*3ALPHA [ extlang ] )
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 *               / 4ALPHA
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 *               / 5*8ALPHA
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 * extlang       = *3( "-" 3ALPHA )
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 * value-chars   = *( pct-encoded / attr-char )
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 * pct-encoded   = "%" HEXDIG HEXDIG
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 * attr-char     = ALPHA / DIGIT
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 *               / "!" / "#" / "$" / "&" / "+" / "-" / "."
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 *               / "^" / "_" / "`" / "|" / "~"
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 * @private
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 */
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var EXT_VALUE_REGEXP = /^([A-Za-z0-9!#$%&+\-^_`{}~]+)'(?:[A-Za-z]{2,3}(?:-[A-Za-z]{3}){0,3}|[A-Za-z]{4,8}|)'((?:%[0-9A-Fa-f]{2}|[A-Za-z0-9!#$&+.^_`|~-])+)$/
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/**
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 * RegExp for various RFC 6266 grammar
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 *
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 * disposition-type = "inline" | "attachment" | disp-ext-type
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 * disp-ext-type    = token
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 * disposition-parm = filename-parm | disp-ext-parm
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 * filename-parm    = "filename" "=" value
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 *                  | "filename*" "=" ext-value
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 * disp-ext-parm    = token "=" value
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 *                  | ext-token "=" ext-value
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 * ext-token        = <the characters in token, followed by "*">
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 * @private
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 */
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var DISPOSITION_TYPE_REGEXP = /^([!#$%&'*+.0-9A-Z^_`a-z|~-]+)[\x09\x20]*(?:$|;)/ // eslint-disable-line no-control-regex
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/**
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 * Create an attachment Content-Disposition header.
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 *
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 * @param {string} [filename]
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 * @param {object} [options]
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 * @param {string} [options.type=attachment]
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 * @param {string|boolean} [options.fallback=true]
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 * @return {string}
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 * @public
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 */
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function contentDisposition (filename, options) {
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  var opts = options || {}
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  // get type
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  var type = opts.type || 'attachment'
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  // get parameters
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  var params = createparams(filename, opts.fallback)
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  // format into string
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  return format(new ContentDisposition(type, params))
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}
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/**
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 * Create parameters object from filename and fallback.
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 *
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 * @param {string} [filename]
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 * @param {string|boolean} [fallback=true]
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 * @return {object}
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 * @private
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 */
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function createparams (filename, fallback) {
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  if (filename === undefined) {
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    return
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  }
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  var params = {}
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  if (typeof filename !== 'string') {
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    throw new TypeError('filename must be a string')
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  }
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  // fallback defaults to true
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  if (fallback === undefined) {
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    fallback = true
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  }
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  if (typeof fallback !== 'string' && typeof fallback !== 'boolean') {
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    throw new TypeError('fallback must be a string or boolean')
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  }
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  if (typeof fallback === 'string' && NON_LATIN1_REGEXP.test(fallback)) {
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    throw new TypeError('fallback must be ISO-8859-1 string')
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  }
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  // restrict to file base name
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  var name = basename(filename)
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  // determine if name is suitable for quoted string
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  var isQuotedString = TEXT_REGEXP.test(name)
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  // generate fallback name
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  var fallbackName = typeof fallback !== 'string'
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    ? fallback && getlatin1(name)
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    : basename(fallback)
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  var hasFallback = typeof fallbackName === 'string' && fallbackName !== name
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  // set extended filename parameter
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  if (hasFallback || !isQuotedString || HEX_ESCAPE_REGEXP.test(name)) {
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    params['filename*'] = name
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  }
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  // set filename parameter
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  if (isQuotedString || hasFallback) {
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    params.filename = hasFallback
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      ? fallbackName
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      : name
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  }
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  return params
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}
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/**
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 * Format object to Content-Disposition header.
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 *
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 * @param {object} obj
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 * @param {string} obj.type
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 * @param {object} [obj.parameters]
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 * @return {string}
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 * @private
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 */
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function format (obj) {
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  var parameters = obj.parameters
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  var type = obj.type
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  if (!type || typeof type !== 'string' || !TOKEN_REGEXP.test(type)) {
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    throw new TypeError('invalid type')
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  }
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  // start with normalized type
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  var string = String(type).toLowerCase()
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  // append parameters
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  if (parameters && typeof parameters === 'object') {
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    var param
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    var params = Object.keys(parameters).sort()
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    for (var i = 0; i < params.length; i++) {
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      param = params[i]
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      var val = param.substr(-1) === '*'
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        ? ustring(parameters[param])
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        : qstring(parameters[param])
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      string += '; ' + param + '=' + val
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    }
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  }
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  return string
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}
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/**
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 * Decode a RFC 6987 field value (gracefully).
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 *
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 * @param {string} str
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 * @return {string}
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 * @private
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 */
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function decodefield (str) {
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  var match = EXT_VALUE_REGEXP.exec(str)
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  if (!match) {
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    throw new TypeError('invalid extended field value')
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  }
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  var charset = match[1].toLowerCase()
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  var encoded = match[2]
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  var value
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  // to binary string
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  var binary = encoded.replace(HEX_ESCAPE_REPLACE_REGEXP, pdecode)
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  switch (charset) {
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    case 'iso-8859-1':
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      value = getlatin1(binary)
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      break
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    case 'utf-8':
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      value = Buffer.from(binary, 'binary').toString('utf8')
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      break
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    default:
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      throw new TypeError('unsupported charset in extended field')
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  }
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  return value
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}
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/**
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 * Get ISO-8859-1 version of string.
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 *
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 * @param {string} val
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 * @return {string}
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 * @private
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 */
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function getlatin1 (val) {
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  // simple Unicode -> ISO-8859-1 transformation
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  return String(val).replace(NON_LATIN1_REGEXP, '?')
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}
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/**
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 * Parse Content-Disposition header string.
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 *
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 * @param {string} string
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 * @return {object}
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 * @public
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 */
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function parse (string) {
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  if (!string || typeof string !== 'string') {
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    throw new TypeError('argument string is required')
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  }
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  var match = DISPOSITION_TYPE_REGEXP.exec(string)
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  if (!match) {
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    throw new TypeError('invalid type format')
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  }
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  // normalize type
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  var index = match[0].length
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  var type = match[1].toLowerCase()
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  var key
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  var names = []
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  var params = {}
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  var value
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  // calculate index to start at
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  index = PARAM_REGEXP.lastIndex = match[0].substr(-1) === ';'
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    ? index - 1
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    : index
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  // match parameters
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  while ((match = PARAM_REGEXP.exec(string))) {
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    if (match.index !== index) {
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      throw new TypeError('invalid parameter format')
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    }
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    index += match[0].length
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    key = match[1].toLowerCase()
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    value = match[2]
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    if (names.indexOf(key) !== -1) {
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      throw new TypeError('invalid duplicate parameter')
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    }
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    names.push(key)
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    if (key.indexOf('*') + 1 === key.length) {
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      // decode extended value
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      key = key.slice(0, -1)
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      value = decodefield(value)
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      // overwrite existing value
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      params[key] = value
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      continue
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    }
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    if (typeof params[key] === 'string') {
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      continue
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    }
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    if (value[0] === '"') {
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      // remove quotes and escapes
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      value = value
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        .substr(1, value.length - 2)
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        .replace(QESC_REGEXP, '$1')
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    }
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    params[key] = value
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  }
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  if (index !== -1 && index !== string.length) {
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    throw new TypeError('invalid parameter format')
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  }
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  return new ContentDisposition(type, params)
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}
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/**
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 * Percent decode a single character.
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 *
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 * @param {string} str
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 * @param {string} hex
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 * @return {string}
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 * @private
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 */
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function pdecode (str, hex) {
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  return String.fromCharCode(parseInt(hex, 16))
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}
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/**
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 * Percent encode a single character.
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 *
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 * @param {string} char
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 * @return {string}
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 * @private
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 */
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function pencode (char) {
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  return '%' + String(char)
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    .charCodeAt(0)
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    .toString(16)
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    .toUpperCase()
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}
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/**
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 * Quote a string for HTTP.
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 *
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 * @param {string} val
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 * @return {string}
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 * @private
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 */
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function qstring (val) {
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  var str = String(val)
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  return '"' + str.replace(QUOTE_REGEXP, '\\$1') + '"'
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}
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/**
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 * Encode a Unicode string for HTTP (RFC 5987).
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 *
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 * @param {string} val
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 * @return {string}
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 * @private
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 */
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function ustring (val) {
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  var str = String(val)
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  // percent encode as UTF-8
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  var encoded = encodeURIComponent(str)
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    .replace(ENCODE_URL_ATTR_CHAR_REGEXP, pencode)
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  return 'UTF-8\'\'' + encoded
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}
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/**
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 * Class for parsed Content-Disposition header for v8 optimization
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 *
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 * @public
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 * @param {string} type
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 * @param {object} parameters
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 * @constructor
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 */
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function ContentDisposition (type, parameters) {
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  this.type = type
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  this.parameters = parameters
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}