# dtdgport.awk

# Reads an XML document from standard input and

# prints a DTD for this document to standard output.

# http://saxon.sourceforge.net/dtdgen.html

# JK 2004-10-09

# JK 2006-03-05

# JK 2007-08-05 Converted for portability from the original dtd_generator.awk

# The program makes an internal list of all the elements

# and attributes that appear in your document, noting how

# they are nested, and noting which elements contain

# character data.

BEGIN {

  while (getXMLEVENT(ARGV[1])) {

    # Remember each element.

    if ( XMLEVENT == "STARTELEM" ) {

      # Remember the parent names of each child node.

      name[XMLDEPTH] = XMLSTARTELEM

      if (XMLDEPTH>1)

        child[name[XMLDEPTH-1], XMLSTARTELEM] ++

      # Count how often the element occurs.

      elem[XMLSTARTELEM] ++

      # Remember all the attributes with the element.

      for (a in XMLATTR)

        attr[XMLSTARTELEM,a] ++

    }

  }

}

END { print_elem(1, name[1]) }   # name[1] is the root

# Print one element (including sub-elements) but only once.

function print_elem(depth, element,   c, atn, chl, n, i, myChildren) {

  if (already_printed[element]++)

    return 

  indent=sprintf("%*s", 2*depth-2, "")

  myChildren=""

  for (c in child) {

    split(c, chl, SUBSEP)

    if (element == chl[1]) {

      if (myChildren=="")

        myChildren = chl[2]

      else

        myChildren = myChildren " | " chl[2]

    }

  }

  # If an element has no child nodes, declare it as such.

  if (myChildren=="")

    print indent ""

  else

    print indent ""

  # After the element name itself, list its attributes.

  for (a in attr) {

    split(a, atn, SUBSEP)

    # Treat only those attributes that belong to the current element.

    if (element == atn[1]) {

      # If an attribute occured each time with its element, notice this. 

      if (attr[element, atn[2]] == elem[element])

        print indent ""

      else

        print indent ""

    }

  }

  # Now go through the child nodes of this elements and print them.

  gsub(/[\|]/, " ", myChildren)

  n=split(myChildren, chl)

  for(i=1; i<=n; i++) {

    print_elem(depth+1, chl[i])

    split(myChildren, chl)

  }

}

##

# getXMLEVENT( file ): # read next xml-data into XMLEVENT,XMLNAME,XMLATTR

#                      # referenced entities are not resolved

# Parameters:

#   file       -- path to xml file

# External variables:

#   XMLEVENT   -- type of item read, e.g. "STARTELEM"(tag), "ENDELEM"(end tag),

#                 "COMMENT"(comment), "CHARDATA"(data)

#   XMLNAME    -- value of item, e.g. tagname if type is "STARTELEM" or "ENDELEM"

#   XMLATTR    -- Map of attributes, only set if XMLEVENT=="STARTELEM"

#   XMLPATH    -- Path to current tag, e.g. /TopLevelTag/SubTag1/SubTag2

#   XMLROW     -- current line number in input file

#   XMLERROR   -- error text, set on parse error

# Returns:

#    1         on successful read: XMLEVENT, XMLNAME, XMLATTR are set accordingly

#    ""        at end of file or parse error, XMLERROR is set on error

# Private Data:

#   _XMLIO     -- buffer, XMLROW, XMLPATH for open files

##

function getXMLEVENT( file            ,end,p,q,tag,att,accu,mline,mode,S0,ex,dtd) {

    XMLEVENT=XMLNAME=XMLERROR=XMLSTARTELEM=XMLENDELEM = ""

    split("", XMLATTR)

    S0    = _XMLIO[file,"S0"]

    XMLROW  = _XMLIO[file,"line"];

    XMLPATH = _XMLIO[file,"path"];

    XMLDEPTH=_XMLIO[file,"depth"]+0;

    dtd   = _XMLIO[file,"dtd"];

    while (!XMLEVENT) {

        if (S0 == "") {

            if (1 != (getline S0 < file))

                break;

             XMLROW ++;

             S0 = S0 RS;

        }

        if (mode == "") {

            mline = XMLROW

            accu=""

            p = substr(S0,1,1)

            if (p != "<" && !(dtd && p=="]"))

                mode="CHARDATA"

            else if (p == "]") {

                S0 = substr(S0,2)

                mode="ENDDOCT"

                end=">"

                dtd=0

            } else if ( substr(S0,1,4) == "

                S0=substr(S0,5)

                mode="COMMENT"

                end="-->"

            } else if ( substr(S0,1,9) == "

                S0 = substr(S0,10)

                mode = "STARTDOCT"

                end  = ">"

            } else if (substr(S0,1,9) == "

                S0 = substr(S0,10)

                mode = "CDA"

                end = "]]>"

            } else if ( substr(S0,1,2) == "

                S0 = substr(S0,3)

                mode = "DEC"

                end = ">"

            } else if (substr(S0,1,2) == "

                S0 = substr(S0,3)

                mode = "PROCINST"

                end = "?>"

            } else if ( substr(S0,1,2)=="</" ) {

                S0 = substr(S0,3)

                mode = "ENDELEM"

                end = ">";

                tag = S0

                sub(/[ \n\r\t>].*$/,"",tag)

                S0 = substr(S0,length(tag)+1)

                ex = XMLPATH

                sub(/\/[^\/]*$/,"",XMLPATH)

                ex = substr(ex, length(XMLPATH)+2)

                if (tag != ex) {

                    XMLERROR = "unexpected close tag <" ex ">..</" tag ">"

                    break

                }

            } else {

                S0 = substr(S0,2)

                mode = "STARTELEM"

                tag = S0

                sub(/[ \n\r\t\/>].*$/,"",tag)

                S0 = substr(S0, length(tag)+1)

                if (tag !~ /^[A-Za-z:_][0-9A-Za-z:_.-]*$/ ) { # /^[[:alpha:]:_][[:alnum:]:_.-]*$/

                    XMLERROR = "invalid tag name '" tag "'"

                    break

                }

                XMLPATH = XMLPATH "/" tag;

            }

        } else if (mode == "CHARDATA") {                            # terminated by "<" or EOF

            p = index(S0, "<")

            if (dtd && (q=index(S0,"]")) && (!p || q

                p = q

            if (p) {

                XMLEVENT = "CHARDATA"

                XMLNAME = accu unescapeXML(substr(S0, 1, p-1))

                S0 = substr(S0, p)

                mode = ""

            } else {

                accu = accu unescapeXML(S0)

                S0 = ""

            }

        } else if ( mode == "STARTELEM" ) {

            sub(/^[ \n\r\t]*/,"",S0)

            if (S0 == "") 

                continue

            if (substr(S0, 1, 2) == "/>" ) {

                S0 = substr(S0, 3)

                mode = ""

                XMLEVENT = "STARTELEM"

                XMLNAME = XMLSTARTELEM = tag

                XMLDEPTH ++

                S0 = "</" tag ">" S0

            } else if (substr(S0, 1, 1) == ">" ) {

                S0 = substr(S0, 2)

                mode = ""

                XMLEVENT = "STARTELEM"

                XMLNAME = XMLSTARTELEM = tag

                XMLDEPTH ++

            } else {

                att = S0

                sub(/[= \n\r\t\/>].*$/,"",att)

                S0 = substr(S0, length(att) + 1)

                mode = "ATTR"

                if (att !~ /^[A-Za-z:_][0-9A-Za-z:_.-]*$/ ) { # /^[[:alpha:]:_][[:alnum:]:_.-]*$/

                    XMLERROR = "invalid attribute name '" att "'"

                    break

                }

            }

        } else if (mode == "ATTR") {

            sub(/^[ \n\r\t]*/, "", S0)

            if (S0 == "") 

                continue

            if (substr(S0,1,1) == "=" ) {

                S0 = substr(S0,2)

                mode = "EQ"

            } else {

                XMLATTR[att] = att

                mode = "STARTELEM"

            }

        } else if (mode == "EQ") {

            sub(/^[ \n\r\t]*/,"",S0)

            if (S0 == "") 

              continue

            end = substr(S0,1,1)

            if (end == "\"" || end == "'") {

                S0 = substr(S0,2)

                accu = ""

                mode = "VALUE"

            } else {

                accu = S0

                sub(/[ \n\r\t\/>].*$/,"", accu)

                S0 = substr(S0, length(accu)+1)

                XMLATTR[att] = unescapeXML(accu)

                mode = "STARTELEM"

            } 

        } else if (mode == "VALUE") {                          # terminated by end

            if (p = index(S0, end)) {

                XMLATTR[att] = accu unescapeXML(substr(S0,1,p-1))

                S0 = substr(S0, p+length(end))

                mode = "STARTELEM"

            } else {

                accu = accu unescapeXML(S0)

                S0=""

            }

        } else if (mode == "STARTDOCT") {                      # terminated by "[" or ">"

            if ((q = index(S0, "[")) && (!(p = index(S0,end)) || q

                XMLEVENT = mode

                XMLNAME = accu substr(S0, 1, q-1)

                S0 = substr(S0, q+1)

                mode = ""

                dtd = 1

            } else if (p = index(S0,end)) {

                XMLEVENT = mode

                XMLNAME = accu substr(S0, 1, p-1)

                S0 = "]" substr(S0, p)

                mode = ""

                dtd = 1

            } else {

                accu = accu S0

                S0 = ""

            }

        } else if (p = index(S0,end)) {  # terminated by end

            XMLEVENT = mode

            XMLNAME = XMLENDELEM = ( mode=="ENDELEM" ? tag : accu substr(S0,1,p-1))

            if (mode=="ENDELEM") XMLDEPTH --

            S0 = substr(S0, p+length(end))

            mode = ""

        } else {

            accu = accu S0

            S0 = ""

        }

    }

    _XMLIO[file, "S0"]   = S0;

    _XMLIO[file, "line"] = XMLROW;

    _XMLIO[file, "path"] = XMLPATH; 

    _XMLIO[file, "depth"] = XMLDEPTH; 

    _XMLIO[file, "dtd"]  = dtd;

    if (mode == "CHARDATA") {

        mode = ""

        if (accu != "")

            XMLEVENT = "CHARDATA"

        XMLNAME = ""

        $0 = accu

    }

    if (XMLEVENT) {

        if (XMLEVENT == "STARTELEM") {

            # Copy attributes into $0.

            NF=0

            for (ex in XMLATTR) {

                NF ++

                $NF = ex

            }

        }

        return 1

    }

    close(file);

    delete _XMLIO[file, "S0"];

    delete _XMLIO[file, "line"];

    delete _XMLIO[file, "path"]; 

    delete _XMLIO[file, "depth"]; 

    delete _XMLIO[file, "dtd"];

    if (XMLERROR)

        XMLERROR = file ":" XMLROW": " XMLERROR 

    else if (mode) XMLERROR=file ":" mline ": " "unterminated " mode

    else if (XMLPATH) XMLERROR=file ":" XMLROW": "  "unclosed tag(s) " XMLPATH 

} # func. getXMLEVENT

# unescape data and attribute values, used by getXMLEVENT

function unescapeXML(text) {

    gsub( "'", "'",  text )

    gsub( """, "\"", text )

    gsub( ">",   ">",  text )

    gsub( "<",   "<",  text )

    gsub( "&",  "\\&",  text)

    return text

}

# close xml file

function closeXMLEVENT(file) {

    close(file);

    delete _XMLIO[file,"S0"]

    delete _XMLIO[file,"line"]

    delete _XMLIO[file,"path"];

    delete _XMLIO[file,"depth"];

    delete _XMLIO[file,"dtd"]

    delete _XMLIO[file,"open"]

    delete _XMLIO[file,"IND"]

}