forked from IntelligenceX/fileconversion
/
RTF 2 Text.go
505 lines (488 loc) · 13.9 KB
/
RTF 2 Text.go
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/*
File Name: RTF 2 Text.go
Copyright: 2018 Kleissner Investments s.r.o.
Author: Peter Kleissner
This code is forked from https://github.com/J45k4/rtf-go and extracts text from RTF files.
It contains an important fix for a bug that was triggered with 06ffe2e7-06b6-41d6-9905-3a225fd55537 with an "index out of range" crash.
It contains another fix to properly decode foreign encodings.
Warning: rtfRegex.FindAllStringSubmatch may use excessive memory! Example System ID that causes problems: 02cf9199-2cda-4fa1-b830-060c67417d2d.
An alternative solution is https://github.com/EndFirstCorp/rtf2txt, but it was found to output everything as one long line without LFs.
*/
package fileconversion
import (
"bytes"
"regexp"
"strconv"
"strings"
"golang.org/x/text/encoding"
"golang.org/x/text/encoding/charmap"
)
var destinations = map[string]bool{
"aftncn": true,
"aftnsep": true,
"aftnsepc": true,
"annotation": true,
"atnauthor": true,
"atndate": true,
"atnicn": true,
"atnid": true,
"atnparent": true,
"atnref": true,
"atntime": true,
"atrfend": true,
"atrfstart": true,
"author": true,
"background": true,
"bkmkend": true,
"bkmkstart": true,
"blipuid": true,
"buptim": true,
"category": true,
"colorschememapping": true,
"colortbl": true,
"comment": true,
"company": true,
"creatim": true,
"datafield": true,
"datastore": true,
"defchp": true,
"defpap": true,
"do": true,
"doccomm": true,
"docvar": true,
"dptxbxtext": true,
"ebcend": true,
"ebcstart": true,
"factoidname": true,
"falt": true,
"fchars": true,
"ffdeftext": true,
"ffentrymcr": true,
"ffexitmcr": true,
"ffformat": true,
"ffhelptext": true,
"ffl": true,
"ffname": true,
"ffstattext": true,
"field": true,
"file": true,
"filetbl": true,
"fldinst": true,
"fldrslt": true,
"fldtype": true,
"fname": true,
"fontemb": true,
"fontfile": true,
"fonttbl": true,
"footer": true,
"footerf": true,
"footerl": true,
"footerr": true,
"footnote": true,
"formfield": true,
"ftncn": true,
"ftnsep": true,
"ftnsepc": true,
"g": true,
"generator": true,
"gridtbl": true,
"header": true,
"headerf": true,
"headerl": true,
"headerr": true,
"hl": true,
"hlfr": true,
"hlinkbase": true,
"hlloc": true,
"hlsrc": true,
"hsv": true,
"htmltag": true,
"info": true,
"keycode": true,
"keywords": true,
"latentstyles": true,
"lchars": true,
"levelnumbers": true,
"leveltext": true,
"lfolevel": true,
"linkval": true,
"list": true,
"listlevel": true,
"listname": true,
"listoverride": true,
"listoverridetable": true,
"listpicture": true,
"liststylename": true,
"listtable": true,
"listtext": true,
"lsdlockedexcept": true,
"macc": true,
"maccPr": true,
"mailmerge": true,
"maln": true,
"malnScr": true,
"manager": true,
"margPr": true,
"mbar": true,
"mbarPr": true,
"mbaseJc": true,
"mbegChr": true,
"mborderBox": true,
"mborderBoxPr": true,
"mbox": true,
"mboxPr": true,
"mchr": true,
"mcount": true,
"mctrlPr": true,
"md": true,
"mdeg": true,
"mdegHide": true,
"mden": true,
"mdiff": true,
"mdPr": true,
"me": true,
"mendChr": true,
"meqArr": true,
"meqArrPr": true,
"mf": true,
"mfName": true,
"mfPr": true,
"mfunc": true,
"mfuncPr": true,
"mgroupChr": true,
"mgroupChrPr": true,
"mgrow": true,
"mhideBot": true,
"mhideLeft": true,
"mhideRight": true,
"mhideTop": true,
"mhtmltag": true,
"mlim": true,
"mlimloc": true,
"mlimlow": true,
"mlimlowPr": true,
"mlimupp": true,
"mlimuppPr": true,
"mm": true,
"mmaddfieldname": true,
"mmath": true,
"mmathPict": true,
"mmathPr": true,
"mmaxdist": true,
"mmc": true,
"mmcJc": true,
"mmconnectstr": true,
"mmconnectstrdata": true,
"mmcPr": true,
"mmcs": true,
"mmdatasource": true,
"mmheadersource": true,
"mmmailsubject": true,
"mmodso": true,
"mmodsofilter": true,
"mmodsofldmpdata": true,
"mmodsomappedname": true,
"mmodsoname": true,
"mmodsorecipdata": true,
"mmodsosort": true,
"mmodsosrc": true,
"mmodsotable": true,
"mmodsoudl": true,
"mmodsoudldata": true,
"mmodsouniquetag": true,
"mmPr": true,
"mmquery": true,
"mmr": true,
"mnary": true,
"mnaryPr": true,
"mnoBreak": true,
"mnum": true,
"mobjDist": true,
"moMath": true,
"moMathPara": true,
"moMathParaPr": true,
"mopEmu": true,
"mphant": true,
"mphantPr": true,
"mplcHide": true,
"mpos": true,
"mr": true,
"mrad": true,
"mradPr": true,
"mrPr": true,
"msepChr": true,
"mshow": true,
"mshp": true,
"msPre": true,
"msPrePr": true,
"msSub": true,
"msSubPr": true,
"msSubSup": true,
"msSubSupPr": true,
"msSup": true,
"msSupPr": true,
"mstrikeBLTR": true,
"mstrikeH": true,
"mstrikeTLBR": true,
"mstrikeV": true,
"msub": true,
"msubHide": true,
"msup": true,
"msupHide": true,
"mtransp": true,
"mtype": true,
"mvertJc": true,
"mvfmf": true,
"mvfml": true,
"mvtof": true,
"mvtol": true,
"mzeroAsc": true,
"mzeroDesc": true,
"mzeroWid": true,
"nesttableprops": true,
"nextfile": true,
"nonesttables": true,
"objalias": true,
"objclass": true,
"objdata": true,
"object": true,
"objname": true,
"objsect": true,
"objtime": true,
"oldcprops": true,
"oldpprops": true,
"oldsprops": true,
"oldtprops": true,
"oleclsid": true,
"operator": true,
"panose": true,
"password": true,
"passwordhash": true,
"pgp": true,
"pgptbl": true,
"picprop": true,
"pict": true,
"pn": true,
"pnseclvl": true,
"pntext": true,
"pntxta": true,
"pntxtb": true,
"printim": true,
"private": true,
"propname": true,
"protend": true,
"protstart": true,
"protusertbl": true,
"pxe": true,
"result": true,
"revtbl": true,
"revtim": true,
"rsidtbl": true,
"rxe": true,
"shp": true,
"shpgrp": true,
"shpinst": true,
"shppict": true,
"shprslt": true,
"shptxt": true,
"sn": true,
"sp": true,
"staticval": true,
"stylesheet": true,
"subject": true,
"sv": true,
"svb": true,
"tc": true,
"template": true,
"themedata": true,
"title": true,
"txe": true,
"ud": true,
"upr": true,
"userprops": true,
"wgrffmtfilter": true,
"windowcaption": true,
"writereservation": true,
"writereservhash": true,
"xe": true,
"xform": true,
"xmlattrname": true,
"xmlattrvalue": true,
"xmlclose": true,
"xmlname": true,
"xmlnstbl": true,
"xmlopen": true,
}
var specialCharacters = map[string]string{
"par": "\n",
"sect": "\n\n",
"page": "\n\n",
"line": "\n",
"tab": "\t",
"emdash": "\u2014",
"endash": "\u2013",
"emspace": "\u2003",
"enspace": "\u2002",
"qmspace": "\u2005",
"bullet": "\u2022",
"lquote": "\u2018",
"rquote": "\u2019",
"ldblquote": "\u201C",
"rdblquote": "\u201D",
}
var charmaps = map[string]*charmap.Charmap{
"437": charmap.CodePage437,
// "708": nil,
// "709": nil,
// "710": nil,
// "711": nil,
// "720": nil,
// "819": nil,
"850": charmap.CodePage850,
"852": charmap.CodePage852,
"860": charmap.CodePage860,
"862": charmap.CodePage862,
"863": charmap.CodePage863,
// "864": nil,
"865": charmap.CodePage865,
"866": charmap.CodePage866,
// "874": nil,
// "932": nil,
// "936": nil,
// "949": nil,
// "950": nil,
"1250": charmap.Windows1250,
"1251": charmap.Windows1251,
"1252": charmap.Windows1252,
"1253": charmap.Windows1253,
"1254": charmap.Windows1254,
"1255": charmap.Windows1255,
"1256": charmap.Windows1256,
"1257": charmap.Windows1257,
"1258": charmap.Windows1258,
// "1361": nil,
}
var rtfRegex = regexp.MustCompile(
"(?i)" +
`\\([a-z]{1,32})(-?\d{1,10})?[ ]?` +
`|\\'([0-9a-f]{2})` +
`|\\([^a-z])` +
`|([{}])` +
`|[\r\n]+` +
`|(.)`)
type stackEntry struct {
NumberOfCharactersToSkip int
Ignorable bool
}
func newStackEntry(numberOfCharactersToSkip int, ignorable bool) stackEntry {
return stackEntry{
NumberOfCharactersToSkip: numberOfCharactersToSkip,
Ignorable: ignorable,
}
}
// RTF2Text removes rtf characters from string and returns the new string.
func RTF2Text(inputRtf string) string {
var charMap *charmap.Charmap
var decoder *encoding.Decoder
var stack []stackEntry
var ignorable bool
ucskip := 1
curskip := 0
matches := rtfRegex.FindAllStringSubmatch(inputRtf, -1)
var returnBuffer bytes.Buffer
for _, match := range matches {
word := match[1]
arg := match[2]
hex := match[3]
character := match[4]
brace := match[5]
tchar := match[6]
switch {
case tchar != "":
if curskip > 0 {
curskip--
} else if !ignorable {
if charMap == nil || decoder == nil {
returnBuffer.WriteString(tchar)
} else {
tcharDec, err := decoder.String(tchar)
if err == nil {
returnBuffer.WriteString(tcharDec)
}
}
}
case brace != "":
curskip = 0
if brace == "{" {
stack = append(
stack, newStackEntry(ucskip, ignorable))
} else if brace == "}" {
// There was a crash here with item 06ffe2e7-06b6-41d6-9905-3a225fd55537
// It's fixed by checking l == 0 and handling it as special case
if l := len(stack); l > 0 {
entry := stack[l-1]
stack = stack[:l-1]
ucskip = entry.NumberOfCharactersToSkip
ignorable = entry.Ignorable
}
}
case character != "":
curskip = 0
if character == "~" {
if !ignorable {
returnBuffer.WriteString("\xA0")
}
} else if strings.Contains("{}\\", character) {
if !ignorable {
returnBuffer.WriteString(character)
}
} else if character == "*" {
ignorable = true
}
case word != "":
curskip = 0
if destinations[word] {
ignorable = true
} else if ignorable {
} else if specialCharacters[word] != "" {
returnBuffer.WriteString(
specialCharacters[word])
} else if word == "ansicpg" {
var ok bool
if charMap, ok = charmaps[arg]; ok {
decoder = charMap.NewDecoder()
} else {
// encoding not supported, continue anyway
}
} else if word == "uc" {
i, _ := strconv.Atoi(arg)
ucskip = i
} else if word == "u" {
c, _ := strconv.Atoi(arg)
if c < 0 {
c += 0x10000
}
returnBuffer.WriteRune(rune(c))
curskip = ucskip
}
case hex != "":
if curskip > 0 {
curskip--
} else if !ignorable {
c, _ := strconv.ParseInt(hex, 16, 0)
if charMap == nil {
returnBuffer.WriteRune(rune(c))
} else {
returnBuffer.WriteRune(
charMap.DecodeByte(byte(c)))
}
}
}
}
return returnBuffer.String()
}
// IsFileRTF checks if the data indicates a RTF file
// RTF has a signature of 7B 5C 72 74 66 31, or in string "{\rtf1"
func IsFileRTF(data []byte) bool {
return bytes.HasPrefix(data, []byte{0x7B, 0x5C, 0x72, 0x74, 0x66, 0x31})
}