awkxml

#!/usr/bin/awk -f

BEGIN {
     while ( getXML(ARGV[1],1) ) {
         printf ("%s %s %s ",XTYPE, XITEM, XPATH);
         for (attrName in XATTR)
             printf ("%s=%s ", attrName, XATTR[attrName]);
         print
     }
     if (XERROR) {
         print XERROR;
         exit 1;
     }

}

##
# getXML( file, skipData ): # read next xml-data into XTYPE,XITEM,XATTR
# Parameters:
#   file       -- path to xml file
#   skipData   -- flag: do not read "DAT" (data between tags) sections
# External variables:
#   XTYPE      -- type of item read, e.g. "TAG"(tag), "END"(end tag), "COM"(comment), "DAT"(data)
#   XITEM      -- value of item, e.g. tagname if type is "TAG" or "END"
#   XATTR      -- Map of attributes, only set if XTYPE=="TAG"
#   XPATH      -- Path to current tag, e.g. /TopLevelTag/SubTag1/SubTag2
#   XLINE      -- current line number in input file
#   XNODE      -- XTYPE, XITEM, XATTR combined into a single string
#   XERROR     -- error text, set on parse error
# Returns:
#    1         on successful read: XTYPE, XITEM, XATTR are set accordingly
#    ""        at end of file or parse error, XERROR is set on error
# Private Data:
#   _XMLIO     -- buffer, XLINE, XPATH for open files
##
function getXML( file, skipData           ,end,p,q,tag,att,accu,mline,mode,S0,ex,dtd) {
     XTYPE=XITEM=XERROR=XNODE=""; split("",XATTR);
     S0=_XMLIO[file,"S0"]; XLINE=_XMLIO[file,"line"]; XPATH=_XMLIO[file,"path"]; dtd=_XMLIO[file,"dtd"];
     while (!XTYPE) {
         if (S0=="") { if (1!=(getline S0 <file)) break; XLINE++; S0=S0 RS; }
         if ( mode == "" ) {
             mline=XLINE; accu=""; p=substr(S0,1,1);
             if ( p!="<" && !(dtd && p=="]") )         mode="DAT";
             else if ( p=="]" ) {                      S0=substr(S0,2);  mode="DTE"; end=">"; dtd=0; }
             else if ( substr(S0,1,4)=="<!--" ) {      S0=substr(S0,5);  mode="COM"; end="-->"; }
             else if ( substr(S0,1,9)=="<!DOCTYPE" ) { S0=substr(S0,10); mode="DTB"; end=">"; }
             else if ( substr(S0,1,9)=="<![CDATA[" ) { 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="PIN"; end="?>"; }
             else if ( substr(S0,1,2)=="</" ) {        S0=substr(S0,3);  mode="END"; end=">";
                 tag=S0;sub(/[ \n\r\t>].*$/,"",tag);S0=substr(S0,length(tag)+1);
                 ex=XPATH;sub(/\/[^\/]*$/,"",XPATH);ex=substr(ex,length(XPATH)+2);
                 if (tag!=ex) { XERROR="unexpected close tag <" ex ">..</" tag ">"; break; } }
             else{                                     S0=substr(S0,2);  mode="TAG";
                 tag=S0;sub(/[ \n\r\t\/>].*$/,"",tag);S0=substr(S0,length(tag)+1);
                 if ( tag !~ /^[A-Za-z:_][0-9A-Za-z:_.-]*$/ ) { # /^[[:alpha:]:_][[:alnum:]:_.-]*$/
                     XERROR="invalid tag name '" tag "'"; break; }
                 XPATH = XPATH "/" tag; } }
         else if ( mode == "DAT" ) {                            # terminated by "<" or EOF
             p=index(S0,"<"); if ( dtd && (q=index(S0,"]")) && (!p || q<p) ) p=q;
             if (p) {
                 if (!skipData) { XTYPE="DAT"; XITEM=accu unescapeXML(substr(S0,1,p-1)); }
                 S0=substr(S0,p); mode=""; }
             else{ if (!skipData) accu=accu unescapeXML(S0); S0=""; } }
         else if ( mode == "TAG" ) {   sub(/^[ \n\r\t]*/,"",S0); if (S0=="") continue;
             if ( substr(S0,1,2)=="/>" ) {
                 S0=substr(S0,3); mode=""; XTYPE="TAG"; XITEM=tag; S0="</"tag">"S0; }
             else if ( substr(S0,1,1)==">" ) {
                 S0=substr(S0,2); mode=""; XTYPE="TAG"; XITEM=tag; }
             else{
                 att=S0; sub(/[= \n\r\t\/>].*$/,"",att); S0=substr(S0,length(att)+1); mode="ATTR";
                 if ( att !~ /^[A-Za-z:_][0-9A-Za-z:_.-]*$/ ) { # /^[[:alpha:]:_][[:alnum:]:_.-]*$/
                     XERROR="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                       { XATTR[att]=att; mode="TAG"; XNODE=XNODE att"="att"\001"; } }
         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);
                 XATTR[att]=unescapeXML(accu); mode="TAG"; XNODE=XNODE att"="XATTR[att]"\001"; } }
         else if ( mode == "VALUE" ) {                          # terminated by end
             if ( p=index(S0,end) ) {
                 XATTR[att]=accu unescapeXML(substr(S0,1,p-1)); XNODE=XNODE att"="XATTR[att]"\001";
                 S0=substr(S0,p+length(end)); mode="TAG"; }
             else{ accu=accu unescapeXML(S0); S0=""; } }
         else if ( mode == "DTB" ) {                            # terminated by "[" or ">"
             if ( (q=index(S0,"[")) && (!(p=index(S0,end)) || q<p ) ) {
                 XTYPE=mode; XITEM= accu substr(S0,1,q-1); S0=substr(S0,q+1); mode=""; dtd=1; }
             else if ( p=index(S0,end) ) {
                 XTYPE=mode; XITEM= 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
             XTYPE=mode; XITEM= ( mode=="END" ? tag : accu substr(S0,1,p-1) );
             S0=substr(S0,p+length(end)); mode=""; }
         else{ accu=accu S0; S0=""; } }
     _XMLIO[file,"S0"]=S0; _XMLIO[file,"line"]=XLINE; _XMLIO[file,"path"]=XPATH; _XMLIO[file,"dtd"]=dtd;
     if (mode=="DAT") { mode=""; if (accu!="") XTYPE="DAT"; XITEM=accu; }
     if (XTYPE) { XNODE=XTYPE"\001"XITEM"\001"XNODE; return 1; }
     close(file);
     delete _XMLIO[file,"S0"]; delete _XMLIO[file,"line"]; delete _XMLIO[file,"path"]; delete _XMLIO[file,"dtd"];
     if (XERROR) XERROR=file ":" XLINE ": " XERROR;
     else if (mode) XERROR=file ":" mline ": " "unterminated " mode;
     else if (XPATH) XERROR=file ":" XLINE ": "  "unclosed tag(s) " XPATH;

} # function getXML

# unescape data and attribute values, used by getXML
function unescapeXML( text ) {
     gsub( "&apos;", "'",  text );
     gsub( "&quot;", "\"", text );
     gsub( "&gt;",   ">",  text );
     gsub( "&lt;",   "<",  text );
     gsub( "&amp;",  "\\&",  text );
     return text

}

# close xml file
function closeXML( file ) {
     close(file);
     delete _XMLIO[file,"S0"]; delete _XMLIO[file,"line"]; delete _XMLIO[file,"path"]; delete _XMLIO[file,"dtd"];
     delete _XMLIO[file,"open"]; delete _XMLIO[file,"IND"];
}