cxlsx_to_csv.c

/*****************************************************************
 NAME:
   cxlsx_to_csv - convert Excel 2007 files to .CSV

 USAGE:
   cxlsx_to_csv -if input.xlsx [-sh sheet_id] [-of output.csv]
  
 COMPILATION:
   cc -DCONFIG_EXPAT -o cxlsx_to_csv cxlsx_to_csv.c -l expat
   or
   cc -DCONFIG_MXML -o cxlsx_to_csv cxlsx_to_csv.c -l mxml
   or
   cc -DCONFIG_PARSIFAL -o cxlsx_to_csv cxlsx_to_csv.c -lparsifal
   or (to benchmark the time used by decompressing step)
   cc -o cxlsx_to_csv cxlsx_to_csv.c
   
 Must be used with Expat compiled for UTF-8 output.

** Copyright (C) 2015 Victor Paesa
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

*****************************************************************/

#include <ctype.h>
#include <stdlib.h>
#include "miniz.c"

typedef unsigned char uint8;
typedef unsigned short uint16;
typedef unsigned int uint;

#include <stdio.h>
#include <string.h>

#ifdef CONFIG_PARSIFAL
#include "libparsifal/parsifal.h"
#endif /* CONFIG_PARSIFAL */

#ifdef CONFIG_MXML
#include <mxml.h>
#endif /* CONFIG_MXML */

#ifdef CONFIG_EXPAT
#include <expat.h>

#if defined(__amigaos__) && defined(__USE_INLINE__)
#include <proto/expat.h>
#endif

#ifdef XML_LARGE_SIZE
#if defined(XML_USE_MSC_EXTENSIONS) && _MSC_VER < 1400
#define XML_FMT_INT_MOD "I64"
#else
#define XML_FMT_INT_MOD "ll"
#endif
#else
#define XML_FMT_INT_MOD "l"
#endif
#endif /* CONFIG_EXPAT */

static char *usage_str = "\n\
NAME:\n\
cxlsx_to_csv - convert Excel 2007 files to .CSV\n\
\n\
SYNOPSIS:\n\
cxlsx_to_csv -if input.xlsx [-sh sheet_id] [-of output.csv]\n\
    input.xlsx        input spreadsheet in Excel 2007 format (Office Open XML)\n\
    sheet_id        name of the sheet within the workbook (default is first one)\n\
    output.csv        output CSV file (default is STDOUT)\n\
\n\
CAVEATS:\n\
Separator in output CSV is comma.\n\
";

// https://support.office.com/en-us/article/Excel-specifications-and-limits-1672b34d-7043-467e-8e27-269d656771c3&usg=AFQjCNHniIQ4KTIFQZ6efVfpDtETwU9Cmw
// Total number of characters that an Excel cell can contain: 32,767
#define BUFFSIZE 40960

/*
** An object used to parse XML content of XLSX
*/
typedef struct XLSXCtx XLSXCtx;
struct XLSXCtx {
  FILE  *outf;
  int    xml_depth;      /* Current dept while parsing the XML tree */
  char **shrdstr_array;
  int    shrdstr_num, shrdstr_cnt;
  int    sheet_num_rows, sheet_num_cols;
  int    current_row, current_col, expected_col;
  int    lookup_v;
#ifdef CONFIG_PARSIFAL
  XMLCH *sheet_cur_ptr;
  XMLCH *sheet_end_ptr;
#endif /* CONFIG_PARSIFAL */
#ifndef CONFIG_MXML
  int    shrdstr_tv;     /* Flag to look for a shared string when inside a <t> or <v> element */
  char  *shrdstr_tv_val; /* Value of a shared string when inside a <t> element in xl/sharedStrings.xml */
                         /* or Index of a shared string when inside a <v> element in xl/worksheets/sheet1.xml */
  char   shrdstr_buff[BUFFSIZE];
#endif /* Not(CONFIG_MXML) = CONFIG_EXPAT || CONFIG_PARSIFAL */
};


/*  
    XLSX files are zip files which contain several xml files with data:
 _rels/.rels
 docProps/app.xml
 docProps/core.xml
 xl/_rels/workbook.xml.rels
 xl/sharedStrings.xml
 xl/worksheets/sheet2.xml
 xl/worksheets/sheet1.xml
 xl/styles.xml
 xl/workbook.xml
 [Content_Types].xml

  The name of each sheet is in xl/workbook.xml
  The individual sheets are kept in xl/worksheets/sheet1.xml
  To save on space, Microsoft stores all the character literal values in one common xl/sharedStrings.xml dictionary file. The individual cell value found for this string in the actual sheet1.xml file is just an index into this dictionary.
  OLEDB created xlsx use inline strings instead of shared ones.
  Some brief tutorial: http://openxmldeveloper.org/files/1928/download.aspx
  Dates are stored as day number since 1900/01/01.
  Time portion of the date is stored as a fraction of a day, so it has to be multiplied by 60*60*24 (86400) to get the actual number os seconds.
  Microsoft does not store empty cells or rows in xl/worksheets/sheet1.xml, so any gaps between values have to be taken care by the code.
  To figure out the number of skipped columns one need to be able to figure out the distance between, say, cell "AB67" and "C67". The way columns are named: A through Z, then AA through AZ, then AAA through AAZ, etc., suggests that we may assume they are using a base-26 system and therefore use a simple conversion method from a base-26 to the decimal system and then use subtraction to find out the number of commas between columns.
    
-------------------------------------------------------------------------
xl/sharedStrings.xml has in "sst:uniqueCount" a count of the number of unique strings
unzip -c 3x2.xlsx xl/sharedStrings.xml | tidy -indent -xml
-------------------------------------------------------------------------
<sst count="9" uniqueCount="5">
  <si>
    <t>Col1</t>
  </si>
  <si>
    <t>Col2</t>
  </si>
  <si>
    <t>Col3</t>
  </si>
  <si>
    <t>a</t>
  </si>
  <si>
    <t>b</t>
  </si>
  <si>
    <t>c</t>
  </si>
</sst>
-------------------------------------------------------------------------

-------------------------------------------------------------------------
xl/worksheets/sheet1.xml has in "dimension:ref" the enclosing range of cells used
unzip -c 3x2.xlsx xl/worksheets/sheet1.xml | tidy -indent -xml
-------------------------------------------------------------------------
<worksheet>
  <dimension ref="A1:C3" />
  <sheetData>
    <row r="1" spans="1:3">
      <c r="A1" t="s">
        <v>0</v>
      </c>
      <c r="B1" t="s">
        <v>1</v>
      </c>
      <c r="C1" t="s">
        <v>27.344</v>
      </c>
    </row>
    <row r="2" spans="1:3">
      <c r="A2" t="s">
        <v>3</v>
      </c>
      <c r="B2" s="1">
        <v>42283</v>
      </c>
      <c r="C2" t="s">
        <v>3</v>
      </c>
    </row>
    <row r="3">
      <c r="A3" t="inlineStr">
        <is>
          <t>some value</t>
        </is>
      </c>
      <c r="B4" t="inlineStr">
        <is>
          <t>some other value</t>
        </is>
      </c>
      <c r="C4" t="inlineStr">
        <is>
          <t>yet some value</t>
        </is>
      </c>
    </row>
  </sheetData>
</worksheet>
-------------------------------------------------------------------------

-------------------------------------------------------------------------
xl/styles.xml
-------------------------------------------------------------------------
<styleSheet>
  <numFmts count="10">
    <numFmt numFmtId="164" formatCode="GENERAL" />
    <numFmt numFmtId="165" formatCode="DD/MM/YY" />
    <numFmt numFmtId="166" formatCode="DD/MM/YYYY" />
    <numFmt numFmtId="167" formatCode="D&quot; de &quot;MMM&quot; de &quot;YY" />
    <numFmt numFmtId="168" formatCode="D&quot; de &quot;MMM&quot; de &quot;YYYY" />
    <numFmt numFmtId="169" formatCode="DDDD, MMMM\ DD&quot;, &quot;YYYY" />
    <numFmt numFmtId="170" formatCode="YYYY\-MM\-DD" />
    <numFmt numFmtId="171" formatCode="YYYY\-MM\-DD" />
    <numFmt numFmtId="172" formatCode="DDDD, D\ MMMM\ YYYY" />
    <numFmt numFmtId="173" formatCode="YYYY\-MM\-DD\ HH:MM:SS.SSS" />
  </numFmts>
</styleSheet>
-------------------------------------------------------------------------



*/

/* CSV escaping:
  If a cell value contains a comma or a line feed, the entire value has to be enclosed in doublequotes.
  If a cell value contains a doublequote each of them has to be doubled and then the value should be enclosed in doublequotes. 
*/

/*
** CSV code from sqlite
*/

/*
** If a field contains any character identified by a 1 in the following
** array, then the string must be quoted for CSV.
*/
static const char needCsvQuote[] = {
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
  1, 0, 1, 0, 0, 0, 0, 1,   0, 0, 0, 0, 0, 0, 0, 0, 
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0, 
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0, 
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0, 
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0, 
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 1, 
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   
};

/*
** Output a single term of CSV.  Actually, colSeparator is used for
** the separator, which may or may not be a comma.  "" is
** the null value.  Strings are quoted if necessary.  The separator
** is only issued if bSep is true.
*/
static inline void output_csv(FILE *out, const char colSeparator, const char *z, int bSep)
{
  if (z==0) {
    //fprintf(out,"%s","");
  } else{
    int i;
    for(i=0; z[i]; i++){
      if (needCsvQuote[((unsigned char*)z)[i]] || (z[i]==colSeparator)) {
        i = 0;
        break;
      }
    }
    if (i==0) {
      putc('"', out);
      for (i=0; z[i]; i++) {
        if (z[i]=='"')
          putc('"', out);
        putc(z[i], out);
      }
      putc('"', out);
    } else {
      fprintf(out, "%s", z);
    }
  }
  if (bSep) {
    putc(colSeparator, out);
  }
}

static inline void excelcolrow(char *string, int *outcol, int *outrow)
{
  int i, col, base;

  col = 0;
  base = 1;
  for (i = 0; i < strlen(string); i++) {
    if (isalpha(string[i])) {
      col = col * 26 + ((toupper(string[i])) - 'A' + 1);
    }
    else
      break;
  }
  *outcol = col;
  *outrow = atoi(string + i);
  return;
}

static inline void rangecolrow(char *string, int *outcol, int *outrow)
{
  int col, row;
  char *coloninstr;

  coloninstr = strchr(string, ':');
  if (coloninstr) {
    string = coloninstr + 1;
    //fprintf(stderr, "rangecolrow: %s \n", string);
  }
  excelcolrow(string, &col, &row);
  *outcol = col;
  *outrow = row;
}

#ifdef CONFIG_EXPAT
static void XMLCALL StartSharedStrings(void *data, const char *el, const char **attr)
{
  int i;
  XLSXCtx *ctx = data;
  
  if ((ctx->xml_depth == 0) && (!strcmp(el, "sst"))) {
    for (i = 0; attr[i]; i += 2) {
      if (!strcmp(attr[i], "uniqueCount")) {
        //fprintf(stderr, " %s='%s'\n", attr[i], attr[i + 1]);
        ctx->shrdstr_cnt = atoi(attr[i + 1]);
        ctx->shrdstr_array = calloc(sizeof(char *), ctx->shrdstr_cnt);
      }
    }
  }
  if (((ctx->xml_depth == 2)||(ctx->xml_depth == 3)) && (!strcmp(el, "t"))) {
    ctx->shrdstr_tv = 1;
    ctx->shrdstr_tv_val = ctx->shrdstr_buff;
    *(ctx->shrdstr_tv_val) = 0;
  }
  ctx->xml_depth++;
}

static void XMLCALL EndSharedStrings(void *data, const char *el)
{
  XLSXCtx *ctx = data;

  ctx->xml_depth--;
  // "t" at depth 3 are due to multiple styles in cell, and then we need to concat the substrings
  if (((ctx->xml_depth == 2)||(ctx->xml_depth == 3)) && (!strcmp(el, "t"))) {
    ctx->shrdstr_tv = 0;
    if (ctx->shrdstr_array[ctx->shrdstr_num]) {
      int prevl, currl;
      char *p;
      prevl = strlen(ctx->shrdstr_array[ctx->shrdstr_num]);
      currl = strlen(ctx->shrdstr_buff);
      p = malloc(sizeof(char) * (prevl + currl + 1));
      memcpy(p, ctx->shrdstr_array[ctx->shrdstr_num], prevl);
      memcpy(p + prevl, ctx->shrdstr_buff, currl);
      p[prevl + currl + 1] = 0;
      free(ctx->shrdstr_array[ctx->shrdstr_num]);
      ctx->shrdstr_array[ctx->shrdstr_num] = p;
    }
    else
      ctx->shrdstr_array[ctx->shrdstr_num] = strdup(ctx->shrdstr_buff);
  }
  if ((ctx->xml_depth == 1) && (!strcmp(el, "si")))
    ctx->shrdstr_num++;
}

static void XMLCALL ChrHndlr(void *data, const char *s, int len)
{
  char *src;
  XLSXCtx *ctx = data;

  if (ctx->shrdstr_tv) {
    src = (char *) s;
    while (len) {
      *(ctx->shrdstr_tv_val)++ = *src++;
      len--;
    }
    *(ctx->shrdstr_tv_val) = 0;
  }
}

static void XMLCALL StartSheet(void *data, const char *el, const char **attr)
{
  int i, j;
  XLSXCtx *ctx = data;

  if ((ctx->xml_depth == 1) && (!strcmp(el, "dimension"))) {
    for (i = 0; attr[i]; i += 2) {
      if (!strcmp(attr[i], "ref")) {
        //fprintf(stderr, "dimension %s='%s'\n", attr[i], attr[i + 1]);
        rangecolrow((char *) attr[i + 1], &(ctx->sheet_num_cols), &(ctx->sheet_num_rows));
        //fprintf(stderr, "cols: %d  rows: %d\n", ctx->sheet_num_cols, ctx->sheet_num_rows);
      }
    }
  }
  if ((ctx->xml_depth == 2) && (!strcmp(el, "row"))) {
    for (i = 0; attr[i]; i += 2) {
      // (!strcmp(attr[i], "r")
      if ((*attr[i] == 'r') && attr[i][1] == '\0') {
        //fprintf(stderr, "row %s='%s'\n", attr[i], attr[i + 1]);
        ctx->expected_col = 1;
      }
    }
  }
  if ((ctx->xml_depth == 3) && (!strcmp(el, "c"))) {
    ctx->lookup_v = 0;
    for (i = 0; attr[i]; i += 2) {
      if (!strcmp(attr[i], "r")) {
        //fprintf(stderr, "c %s='%s'\n", attr[i], attr[i + 1]);
        excelcolrow((char *) attr[i + 1], &(ctx->current_col), &(ctx->current_row));
        for (j = ctx->expected_col; (j<ctx->current_col)&&(j<ctx->sheet_num_cols); j++)
          putc(',', ctx->outf);
        ctx->expected_col = ctx->current_col+1;
      }
      else if (!strcmp(attr[i], "t")) {
        //fprintf(stderr, "c %s='%s'\n", attr[i], attr[i + 1]);
        if (*attr[i + 1] == 's') {
          ctx->lookup_v = -1;
        }
        //fprintf(stderr, "cols: %d  rows: %d\n", ctx->sheet_num_cols, ctx->sheet_num_rows);
      }
    }
  }
  if ((ctx->xml_depth == 4) && (*el == 'v') && (el[1] == '\0')) {
    ctx->shrdstr_tv = 1;
    ctx->shrdstr_tv_val = ctx->shrdstr_buff;
    *(ctx->shrdstr_tv_val) = 0;
  }
  ctx->xml_depth++;
}

static void XMLCALL EndSheet(void *data, const char *el)
{
  int j;
  XLSXCtx *ctx = data;

  ctx->xml_depth--;
  if ((ctx->xml_depth == 4) && (*el == 'v') && (el[1] == '\0')) {
    ctx->shrdstr_tv = 0;
    if (ctx->lookup_v) {
      //fprintf(stderr, "v %s\n", ctx->shrdstr_array[atoi(ctx->shrdstr_buff)]);
      output_csv(ctx->outf, ',', ctx->shrdstr_array[atoi(ctx->shrdstr_buff)], (ctx->current_col < ctx->sheet_num_cols));
    }
    else {
      //fprintf(stderr, "v %s\n", ctx->shrdstr_buff);
      output_csv(ctx->outf, ',', ctx->shrdstr_buff, (ctx->current_col < ctx->sheet_num_cols));
    }
  }
  if ((ctx->xml_depth == 2) && (!strcmp(el, "row"))) {
    for (j = ctx->expected_col; j<ctx->sheet_num_cols; j++)
      putc(',', ctx->outf);
    fprintf(ctx->outf, "\r\x0A");
    // TODO: Check if \r\x0A portable between Windows & UNIX
  }
}
#endif /* CONFIG_EXPAT */

#ifdef CONFIG_MXML
static void SharedStrings(mxml_node_t *node, mxml_sax_event_t event, void *data)
{
  const char *el, *uniqueCount, *value;
  XLSXCtx *ctx = data;
  
  if (event == MXML_SAX_ELEMENT_OPEN) {
    if (ctx->xml_depth == 0) {
      el = mxmlGetElement(node);
      if (!strcmp(el, "sst")) {
        uniqueCount = mxmlElementGetAttr(node, "uniqueCount");
        if (uniqueCount) {
          //fprintf(stderr, " uniqueCount='%s'\n", uniqueCount);
          ctx->shrdstr_cnt = atoi(uniqueCount);
          ctx->shrdstr_array = malloc(sizeof(char *) * ctx->shrdstr_cnt);
        }
      }
    }
    ctx->xml_depth++;
    //fprintf(stderr, "shared strings '%s' %d\n", el, ctx->xml_depth);
  }
  else if (event == MXML_SAX_DATA) {
    if (ctx->xml_depth == 3) {
      el = mxmlGetElement(mxmlGetParent(node));
      if (!strcmp(el, "t")) {
        value = mxmlGetOpaque(mxmlGetParent(node));
        //fprintf(stderr, " shrStr[%d]='%s'\n", ctx->shrdstr_num, value);
        ctx->shrdstr_array[ctx->shrdstr_num] = strdup(value);
        ctx->shrdstr_num++;
      }
    }
  }
  else if (event == MXML_SAX_ELEMENT_CLOSE) {
    ctx->xml_depth--;
  }
}

static void Sheet(mxml_node_t *node, mxml_sax_event_t event, void *data)
{
  int i, j;
  const char *el, *ref, *r, *t, *value;
  XLSXCtx *ctx = data;

  if (event == MXML_SAX_ELEMENT_OPEN) {
    el = mxmlGetElement(node);
    if ((ctx->xml_depth == 1) && (!strcmp(el, "dimension"))) {
      ref = mxmlElementGetAttr(node, "ref");
      if (ref) {
        rangecolrow((char *)ref, &(ctx->sheet_num_cols), &(ctx->sheet_num_rows));
        //fprintf(stderr, " dimension ref='%s'\n", ref);
        //fprintf(stderr, "cols: %d  rows: %d\n", ctx->sheet_num_cols, ctx->sheet_num_rows);
      }
    }
    if ((ctx->xml_depth == 2) && (!strcmp(el, "row"))) {
      r = mxmlElementGetAttr(node, "r");
      if (r) {
        //fprintf(stderr, "row r='%s'\n", r);
        ctx->expected_col = 1;
      }
    }
    if ((ctx->xml_depth == 3) && (!strcmp(el, "c"))) {
      ctx->lookup_v = 0;
      r = mxmlElementGetAttr(node, "r");
      if (r) {
        //fprintf(stderr, "c r='%s'\n", r);
        excelcolrow((char *)r, &(ctx->current_col), &(ctx->current_row));
        for (j = ctx->expected_col; (j<ctx->current_col)&&(j<ctx->sheet_num_cols); j++)
          putc(',', ctx->outf);
        ctx->expected_col = ctx->current_col+1;
      }
      t = mxmlElementGetAttr(node, "t");
      if (t) {
        //fprintf(stderr, "c t='%s'\n", t);
        if (*t == 's') {
          ctx->lookup_v = -1;
        }
        //fprintf(stderr, "cols: %d  rows: %d\n", ctx->sheet_num_cols, ctx->sheet_num_rows);
      }
    }
    ctx->xml_depth++;
  }
  else if (event == MXML_SAX_DATA) {
    if (ctx->xml_depth == 5) {
      el = mxmlGetElement(mxmlGetParent(node));
      if (!strcmp(el, "v")) {
        value = mxmlGetOpaque(mxmlGetParent(node));
        if (ctx->lookup_v) {
          //fprintf(stderr, "v %s\n", ctx->shrdstr_array[atoi(value)]);
          output_csv(ctx->outf, ',', ctx->shrdstr_array[atoi(value)], (ctx->current_col < ctx->sheet_num_cols));
        }
        else {
          //fprintf(stderr, "v %s\n", value);
          output_csv(ctx->outf, ',', value, (ctx->current_col < ctx->sheet_num_cols));
        }
      }
    }
  }
  else if (event == MXML_SAX_ELEMENT_CLOSE) {
    ctx->xml_depth--;
    if (ctx->xml_depth == 2) {
      el = mxmlGetElement(node);
      if (!strcmp(el, "row")) {
        for (j = ctx->expected_col; j<ctx->sheet_num_cols; j++)
          putc(',', ctx->outf);
        fprintf(ctx->outf, "\r\x0A");
        // TODO: Check if \r\x0A portable between Windows & UNIX
      }
    }
  }
}
#endif /* CONFIG_MXML */

#ifdef CONFIG_PARSIFAL
int StartSharedStrings(void *data, const XMLCH *uri, const XMLCH *localName, const XMLCH *el, LPXMLVECTOR atts)
{
  int i;
  LPXMLRUNTIMEATT att;
  XLSXCtx *ctx = data;
  
  if ((ctx->xml_depth == 0) && (!strcmp(el, "sst"))) {
    for (i = 0; i<atts->length; i++) {
      att = (LPXMLRUNTIMEATT) XMLVector_Get(atts, i);
      if (!strcmp(att->qname, "uniqueCount")) {
        //fprintf(stderr, " %s='%s'\n", att->qname, att->value);
        ctx->shrdstr_cnt = atoi(att->value);
        ctx->shrdstr_array = malloc(sizeof(char *) * ctx->shrdstr_cnt);
      }
    }
  }
  if ((ctx->xml_depth == 2) && (!strcmp(el, "t"))) {
    ctx->shrdstr_tv = 1;
    ctx->shrdstr_tv_val = ctx->shrdstr_buff;
    *(ctx->shrdstr_tv_val) = 0;
  }
  ctx->xml_depth++;
  return 0;
}

int EndSharedStrings(void *data, const XMLCH *uri, const XMLCH *localName, const XMLCH *el)
{
  XLSXCtx *ctx = data;

  ctx->xml_depth--;
  if ((ctx->xml_depth == 2) && (!strcmp(el, "t"))) {
    ctx->shrdstr_tv = 0;
    ctx->shrdstr_array[ctx->shrdstr_num] = strdup(ctx->shrdstr_buff);
    ctx->shrdstr_num++;
  }
  return 0;
}

int ChrHndlr(void *data, const XMLCH *s, int len)
{
  XMLCH *src;
  XLSXCtx *ctx = data;

  if (ctx->shrdstr_tv) {
    src = (XMLCH *) s;
    while (len) {
      *(ctx->shrdstr_tv_val)++ = *src++;
      len--;
    }
    *(ctx->shrdstr_tv_val) = 0;
  }
  return 0;
}

int StartSheet(void *data, const XMLCH *uri, const XMLCH *localName, const XMLCH *el, LPXMLVECTOR atts)
{
  int i, j;
  LPXMLRUNTIMEATT att;
  XLSXCtx *ctx = data;

  if ((ctx->xml_depth == 1) && (!strcmp(el, "dimension"))) {
    for (i = 0; i<atts->length; i++) {
      att = (LPXMLRUNTIMEATT) XMLVector_Get(atts, i);
      if (!strcmp(att->qname, "ref")) {
        //fprintf(stderr, "dimension %s='%s'\n", att->qname, att->value);
        rangecolrow((char *) att->value, &(ctx->sheet_num_cols), &(ctx->sheet_num_rows));
        //fprintf(stderr, "cols: %d  rows: %d\n", ctx->sheet_num_cols, ctx->sheet_num_rows);
      }
    }
  }
  if ((ctx->xml_depth == 2) && (!strcmp(el, "row"))) {
    for (i = 0; i<atts->length; i++) {
      att = (LPXMLRUNTIMEATT) XMLVector_Get(atts, i);
      if (!strcmp(att->qname, "r")) {
        //fprintf(stderr, "row %s='%s'\n", att->qname, att->value);
        ctx->expected_col = 1;
      }
    }
  }
  if ((ctx->xml_depth == 3) && (!strcmp(el, "c"))) {
    ctx->lookup_v = 0;
    for (i = 0; i<atts->length; i++) {
      att = (LPXMLRUNTIMEATT) XMLVector_Get(atts, i);
      if (!strcmp(att->qname, "r")) {
        //fprintf(stderr, "c %s='%s'\n", att->qname, att->value);
        excelcolrow((char *) att->value, &(ctx->current_col), &(ctx->current_row));
        for (j = ctx->expected_col; (j<ctx->current_col)&&(j<ctx->sheet_num_cols); j++)
          putc(',', ctx->outf);
        ctx->expected_col = ctx->current_col+1;
      }
      else if (!strcmp(att->qname, "t")) {
        //fprintf(stderr, "c %s='%s'\n", att->qname, att->value);
        if (*(att->value) == 's') {
          ctx->lookup_v = -1;
        }
        //fprintf(stderr, "cols: %d  rows: %d\n", ctx->sheet_num_cols, ctx->sheet_num_rows);
      }
    }
  }
  if ((ctx->xml_depth == 4) && (*el == 'v') && (el[1] == '\0')) {
    ctx->shrdstr_tv = 1;
    ctx->shrdstr_tv_val = ctx->shrdstr_buff;
    *(ctx->shrdstr_tv_val) = 0;
  }
  ctx->xml_depth++;
  return 0;
}

int EndSheet(void *data, const XMLCH *uri, const XMLCH *localName, const XMLCH *el)
{
  int j;
  XLSXCtx *ctx = data;

  ctx->xml_depth--;
  if ((ctx->xml_depth == 4) && (*el == 'v') && (el[1] == '\0')) {
    ctx->shrdstr_tv = 0;
    if (ctx->lookup_v) {
      //fprintf(stderr, "v %s\n", ctx->shrdstr_array[atoi(ctx->shrdstr_buff)]);
      output_csv(ctx->outf, ',', ctx->shrdstr_array[atoi(ctx->shrdstr_buff)], (ctx->current_col < ctx->sheet_num_cols));
    }
    else {
      //fprintf(stderr, "v %s\n", ctx->shrdstr_buff);
      output_csv(ctx->outf, ',', ctx->shrdstr_buff, (ctx->current_col < ctx->sheet_num_cols));
    }
  }
  if ((ctx->xml_depth == 2) && (!strcmp(el, "row"))) {
    for (j = ctx->expected_col; j<ctx->sheet_num_cols; j++)
      putc(',', ctx->outf);
    fprintf(ctx->outf, "\r\x0A");
    // TODO: Check if \r\x0A portable between Windows & UNIX
  }
  return 0;
}

int GetSheetBytes(BYTE *buf, int cBytes, int *cBytesActual, void *data)
{
  XLSXCtx *ctx = data;
  char str[64];

  //snprintf(str, 64, "%s", ctx->sheet_cur_ptr);
  //fprintf(stderr, "GetSheetBytes %p %d '%s'\n", ctx->sheet_cur_ptr, cBytes, str);
  if ((ctx->sheet_end_ptr - ctx->sheet_cur_ptr) >= cBytes) {
    memcpy(buf, ctx->sheet_cur_ptr, cBytes);
    *cBytesActual = cBytes;
    ctx->sheet_cur_ptr += cBytes;
    return 0;
  }
  else {
    *cBytesActual = ctx->sheet_end_ptr - ctx->sheet_cur_ptr;
    memcpy(buf, ctx->sheet_cur_ptr, *cBytesActual);
    ctx->sheet_cur_ptr = ctx->sheet_end_ptr;
    return 1;
  }
}

void ErrorHandler(LPXMLPARSER parser) {} /* dummy, only for switching ErrorString etc. on */
#endif /* CONFIG_PARSIFAL */

int main(int argc, char *argv[])
{
  int i;
  size_t sheet_size;
  void *sheet_ptr;
  XLSXCtx *parse_ctx;
  char sheetname[64];
#ifdef CONFIG_EXPAT
  XML_Parser p;
#endif /* CONFIG_EXPAT */
#ifdef CONFIG_MXML
  mxml_node_t *root_node;
#endif /* CONFIG_MXML */
#ifdef CONFIG_PARSIFAL
  LPXMLPARSER parser;
#endif /* CONFIG_PARSIFAL */
  
  int opt_if = 0;
  int opt_sh = 0;
  int opt_of = 0;

  parse_ctx = calloc(1, sizeof(XLSXCtx));
  for (i=1; i<argc; i++) {
    if (i==opt_if)
      continue;
    if (!strcmp("-if", argv[i]))
      if ((i+1) < argc)
        opt_if = i+1;
      else {
        fputs("'-if' needs an Excel file name for input\n", stderr);
        fputs(usage_str, stderr);
        return 1;
      }
    if (i==opt_sh)
      continue;
    if (!strcmp("-sh", argv[i]))
      if ((i+1) < argc)
        opt_sh = i+1;
      else {
        fputs("'-sh' needs a sheet number\n", stderr);
        fputs(usage_str, stderr);
        return 1;
      }
    if (i==opt_of)
      continue;
    if (!strcmp("-of", argv[i]))
      if ((i+1) < argc)
        opt_of = i+1;
      else {
        fputs("'-of' needs an CSV file name for output\n", stderr);
        fputs(usage_str, stderr);
        return 1;
      }
  }

  if (!opt_if) {
    fputs("Missing '-if input.xlsx'\n", stderr);
    fputs(usage_str, stderr);
    return 1;
  }
  if (!opt_sh) {
    //fputs("Missing '-sh sheetnum', hence assuming first sheet.\n", stderr);
    opt_sh = 1;
  }
  else {
    opt_sh = atoi(argv[opt_sh]);
    // TODO: Check sheet number among existing sheets. Accept sheet names.
    if (!opt_sh)
      opt_sh = 1;
  }
  if (!opt_of) {
    //fputs("Missing '-of output.csv', hence assuming STDOUT.\n", stderr);
    parse_ctx->outf = stdout; 
  }
  else {
    parse_ctx->outf = fopen(argv[opt_of], "w");
    if (!parse_ctx->outf) {
      fprintf(stderr, "Couldn't open output file '%s' .\n", argv[opt_of]);
      exit(-1);
    }
  }

  // Process xl/sharedStrings.xml and load them into shrdstr_array[]
  sheet_ptr = mz_zip_extract_archive_file_to_heap(argv[opt_if], "xl/sharedStrings.xml", &sheet_size, MZ_ZIP_FLAG_CASE_SENSITIVE);
  //fprintf(stderr, "xl/sharedStrings.xml size:%d\n", sheet_size);
  if (sheet_ptr) {
    parse_ctx->xml_depth = 0;
#ifdef CONFIG_EXPAT  
    p = XML_ParserCreate(NULL);
    if (!p) {
      fprintf(stderr, "Couldn't allocate memory for parser\n");
      exit(-1);
    }
    XML_SetUserData(p, parse_ctx);
    XML_SetElementHandler(p, StartSharedStrings, EndSharedStrings);
    XML_SetCharacterDataHandler(p, ChrHndlr);
    if (XML_Parse(p, sheet_ptr, sheet_size, -1) == XML_STATUS_ERROR) {
      fprintf(stderr, "Parse error at line %" XML_FMT_INT_MOD "u:\n%s\n",
               XML_GetCurrentLineNumber(p),
               XML_ErrorString(XML_GetErrorCode(p)));
      exit(-1);
    }
    XML_ParserFree(p);
    //for (i = 0; i < ctx->shrdstr_cnt; i++)
    //  printf("%s\n", ctx->shrdstr_array[i]);
#endif /* CONFIG_EXPAT */
#ifdef CONFIG_MXML
    root_node = mxmlSAXLoadString(NULL, sheet_ptr, MXML_OPAQUE_CALLBACK, SharedStrings, parse_ctx);
#endif /* CONFIG_MXML */
#ifdef CONFIG_PARSIFAL
    if (!XMLParser_Create(&parser)) {
      printf("Error creating parser!\n");
      exit(-1);
    }
    _XMLParser_SetFlag(parser, XMLFLAG_NAMESPACES, 0);
    _XMLParser_SetFlag(parser, XMLFLAG_EXTERNAL_GENERAL_ENTITIES, 0);
    _XMLParser_SetFlag(parser, XMLFLAG_PRESERVE_WS_ATTRIBUTES, -1);
    parser->errorHandler = ErrorHandler;
    parser->startElementHandler = StartSharedStrings;
    parser->endElementHandler = EndSharedStrings;
    parser->charactersHandler = ChrHndlr;
    parser->UserData = parse_ctx;
    parse_ctx->sheet_cur_ptr = sheet_ptr;
    parse_ctx->sheet_end_ptr = sheet_ptr + sheet_size;
    if (!XMLParser_Parse(parser, GetSheetBytes, parse_ctx, "UTF-8"))
      printf("ShareStrings Error: %s\nLine: %d Col: %d\n", parser->ErrorString, parser->ErrorLine, parser->ErrorColumn);
    XMLParser_Free(parser);
#endif /* CONFIG_PARSIFAL */
  }
  else {
    //fprintf(stderr, "Warning: could not read xl/sharedStrings.xml\n");
    // TODO: Only warn about missing xl/sharedStrings.xml is it referenced by some t="s"
  }

  // Process xl/worksheets/sheet1.xml and load them into sheet_tbl[,]
  sprintf(sheetname, "xl/worksheets/sheet%d.xml", opt_sh);
  sheet_ptr = mz_zip_extract_archive_file_to_heap(argv[opt_if], sheetname, &sheet_size, MZ_ZIP_FLAG_CASE_SENSITIVE);
  //fprintf(stderr, "%s size:%d\n", sheetname, sheet_size);
  if (sheet_ptr) {
    parse_ctx->xml_depth = 0;
#ifdef CONFIG_EXPAT  
    parse_ctx->shrdstr_tv = 0;
    p = XML_ParserCreate(NULL);
    if (!p) {
      fprintf(stderr, "Couldn't allocate memory for parser\n");
      exit(-1);
    }
    XML_SetUserData(p, parse_ctx);
    XML_SetElementHandler(p, StartSheet, EndSheet);
    XML_SetCharacterDataHandler(p, ChrHndlr);
    if (XML_Parse(p, sheet_ptr, sheet_size, -1) == XML_STATUS_ERROR) {
      fprintf(stderr, "Parse error at line %" XML_FMT_INT_MOD "u:\n%s\n",
               XML_GetCurrentLineNumber(p),
               XML_ErrorString(XML_GetErrorCode(p)));
      exit(-1);
    }
    XML_ParserFree(p);
#endif /* CONFIG_EXPAT */
#ifdef CONFIG_MXML
    root_node = mxmlSAXLoadString(NULL, sheet_ptr, MXML_OPAQUE_CALLBACK, Sheet, parse_ctx);
#endif /* CONFIG_MXML */
#ifdef CONFIG_PARSIFAL
    if (!XMLParser_Create(&parser)) {
      printf("Error creating parser!\n");
      exit(-1);
    }
    _XMLParser_SetFlag(parser, XMLFLAG_NAMESPACES, 0);
    _XMLParser_SetFlag(parser, XMLFLAG_EXTERNAL_GENERAL_ENTITIES, 0);
    _XMLParser_SetFlag(parser, XMLFLAG_PRESERVE_WS_ATTRIBUTES, -1);
    parser->errorHandler = ErrorHandler;
    parser->startElementHandler = StartSheet;
    parser->endElementHandler = EndSheet;
    parser->charactersHandler = ChrHndlr;
    parser->UserData = parse_ctx;
    parse_ctx->sheet_cur_ptr = sheet_ptr;
    parse_ctx->sheet_end_ptr = sheet_ptr + sheet_size;
    if (!XMLParser_Parse(parser, GetSheetBytes, parse_ctx, "UTF-8"))
      printf("Sheet Error: %s\nLine: %d Col: %d\n", parser->ErrorString, parser->ErrorLine, parser->ErrorColumn);
    XMLParser_Free(parser);
#endif /* CONFIG_PARSIFAL */
  }
  else {
    fprintf(stderr, "Error: could not read sheet number %d.\n", opt_sh);
    exit(-1);
  }

  return 0;
}