#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/param.h>
#include <unistd.h>
#include <time.h>


/*
** Size of the write buffer used by journal files in bytes.
*/
#ifndef SQLITE_DEMOVFS_BUFFERSZ
# define SQLITE_DEMOVFS_BUFFERSZ 8192
#endif






/*
** When using this VFS, the sqlite3_file* handles that SQLite uses are
** actually pointers to instances of type DemoFile.
*/
typedef struct DemoFile DemoFile;
struct DemoFile {
  sqlite3_file base;              /* Base class. Must be first. */
................................................................................

/*
** Delete the file identified by argument zPath. If the dirSync parameter
** is non-zero, then ensure the file-system modification to delete the
** file has been synced to disk before returning.
*/
static int demoDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  int rc;

  rc = unlink(zPath);


  if( rc==0 && dirSync ){
    int dfd;                      /* File descriptor open on directory */
    int i;                        /* Iterator variable */
    char zDir[pVfs->mxPathname+1];/* Name of directory containing file zPath */

    /* Figure out the directory name from the path of the file deleted. */
    sqlite3_snprintf(pVfs->mxPathname, zDir, "%s", zPath);
    zDir[pVfs->mxPathname] = '\0';
    for(i=strlen(zDir); i>1 && zDir[i]!='/'; i++);
    zDir[i] = '\0';

    /* Open a file-descriptor on the directory. Sync. Close. */
    dfd = open(zDir, O_RDONLY, 0);
    if( dfd<0 ){
      rc = -1;
................................................................................
*/
static int demoFullPathname(
  sqlite3_vfs *pVfs,              /* VFS */
  const char *zPath,              /* Input path (possibly a relative path) */
  int nPathOut,                   /* Size of output buffer in bytes */
  char *zPathOut                  /* Pointer to output buffer */
){
  char zDir[pVfs->mxPathname+1];
  if( zPath[0]=='/' ){
    zDir[0] = '\0';
  }else{
    getcwd(zDir, sizeof(zDir));
  }
  zDir[pVfs->mxPathname] = '\0';

  sqlite3_snprintf(nPathOut, zPathOut, "%s/%s", zDir, zPath);
  zPathOut[nPathOut-1] = '\0';

  return SQLITE_OK;
}

................................................................................
**
**   sqlite3_vfs_register(sqlite3_demovfs(), 0);
*/
sqlite3_vfs *sqlite3_demovfs(void){
  static sqlite3_vfs demovfs = {
    1,                            /* iVersion */
    sizeof(DemoFile),             /* szOsFile */
    512,                          /* mxPathname */
    0,                            /* pNext */
    "demo",                       /* zName */
    0,                            /* pAppData */
    demoOpen,                     /* xOpen */
    demoDelete,                   /* xDelete */
    demoAccess,                   /* xAccess */
    demoFullPathname,             /* xFullPathname */

#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/param.h>
#include <unistd.h>
#include <time.h>
#include <errno.h>

/*
** Size of the write buffer used by journal files in bytes.
*/
#ifndef SQLITE_DEMOVFS_BUFFERSZ
# define SQLITE_DEMOVFS_BUFFERSZ 8192
#endif

/*
** The maximum pathname length supported by this VFS.
*/
#define MAXPATHNAME 512

/*
** When using this VFS, the sqlite3_file* handles that SQLite uses are
** actually pointers to instances of type DemoFile.
*/
typedef struct DemoFile DemoFile;
struct DemoFile {
  sqlite3_file base;              /* Base class. Must be first. */
................................................................................

/*
** Delete the file identified by argument zPath. If the dirSync parameter
** is non-zero, then ensure the file-system modification to delete the
** file has been synced to disk before returning.
*/
static int demoDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  int rc;                         /* Return code */

  rc = unlink(zPath);
  if( rc!=0 && errno==ENOENT ) return SQLITE_OK;

  if( rc==0 && dirSync ){
    int dfd;                      /* File descriptor open on directory */
    int i;                        /* Iterator variable */
    char zDir[MAXPATHNAME+1];     /* Name of directory containing file zPath */

    /* Figure out the directory name from the path of the file deleted. */
    sqlite3_snprintf(MAXPATHNAME, zDir, "%s", zPath);
    zDir[MAXPATHNAME] = '\0';
    for(i=strlen(zDir); i>1 && zDir[i]!='/'; i++);
    zDir[i] = '\0';

    /* Open a file-descriptor on the directory. Sync. Close. */
    dfd = open(zDir, O_RDONLY, 0);
    if( dfd<0 ){
      rc = -1;
................................................................................
*/
static int demoFullPathname(
  sqlite3_vfs *pVfs,              /* VFS */
  const char *zPath,              /* Input path (possibly a relative path) */
  int nPathOut,                   /* Size of output buffer in bytes */
  char *zPathOut                  /* Pointer to output buffer */
){
  char zDir[MAXPATHNAME+1];
  if( zPath[0]=='/' ){
    zDir[0] = '\0';
  }else{
    getcwd(zDir, sizeof(zDir));
  }
  zDir[MAXPATHNAME] = '\0';

  sqlite3_snprintf(nPathOut, zPathOut, "%s/%s", zDir, zPath);
  zPathOut[nPathOut-1] = '\0';

  return SQLITE_OK;
}

................................................................................
**
**   sqlite3_vfs_register(sqlite3_demovfs(), 0);
*/
sqlite3_vfs *sqlite3_demovfs(void){
  static sqlite3_vfs demovfs = {
    1,                            /* iVersion */
    sizeof(DemoFile),             /* szOsFile */
    MAXPATHNAME,                  /* mxPathname */
    0,                            /* pNext */
    "demo",                       /* zName */
    0,                            /* pAppData */
    demoOpen,                     /* xOpen */
    demoDelete,                   /* xDelete */
    demoAccess,                   /* xAccess */
    demoFullPathname,             /* xFullPathname */