se.moevm.info

// Programming 1. Sample at 2017-04-13-13-54.09
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
 
const size_t BUFFERSZ = 1000;
int g_location_items = 0;
 
struct LocationIterator 
{
  long   filepos;
  char   location[20];
  struct LocationIterator *next;
};
 
struct LocationIterator *locations = NULL;
struct LocationIterator **nextLocationItem = &locations;
 
// shifts <location> to the beginning of the buf 
void shift_buffer(char *buf, size_t size, size_t tailsz, FILE *file)
{
  memmove(buf,buf+size,(BUFFERSZ-1)-size);
  int rsz = fread(buf+((BUFFERSZ-1)-size),1,size,file);
  buf[rsz]=0;
}
 
void extractLocation(const char *src, char *dest)
{
  memset(dest,0,20);
  const char * endTag = strstr(src,"<");
  if(NULL == endTag || (endTag - src)>19)
    strncpy(dest,src,19);
  else
    strncpy(dest,src,endTag-src);
}
 
// add new LocationItem
void addLocation(const char *tag, FILE *file)
{
  const char *locationValue = tag+strlen("<location>");
 
  *nextLocationItem = 
        (struct LocationIterator*)malloc(sizeof(struct LocationIterator));
 
  (*nextLocationItem)->filepos = ftell(file)-(BUFFERSZ-1);
 
  extractLocation(locationValue,(*nextLocationItem)->location);
 
  printf("%d: Location: [%s] \n",g_location_items++, (*nextLocationItem)->location);
 
  *nextLocationItem=(*nextLocationItem)->next;
 
 
}
 
// Search the next <location> tag
void find_all_locations(FILE *file, char *buf)
{
  char *startTag = NULL;
  char *locationPtr = NULL;
  do
  {
    size_t rd = fread(buf, 1, BUFFERSZ-1, file);  
    if(rd <= 1)
      break;
 
    startTag=strchr(buf,'<');  
 
    // read the next buffer, there's no < 
    if( NULL == startTag)
      continue;
 
    shift_buffer(buf, startTag-buf, startTag-buf, file);
 
    locationPtr = strstr(buf, "<location>");
 
    if(buf == locationPtr)
      addLocation(buf,file);
 
  } while(!feof(file));
 
}
 
void initLocations(const char *filename)
{
  char buf[BUFFERSZ];
 
  FILE *file = fopen(filename,"r");
   printf("file = %p\n",file);
 
  if(NULL == file)
    return;
 
  memset(buf,0,BUFFERSZ);
  find_all_locations(file, buf);
  fclose(file);
 
}
 
int main(/*int c, char **v */)
{
 
  initLocations("./database");
  return 0;
}