** Any prior content of the blob is discarded, not freed.
**
** Returns length of destination path.
**
** On windows, zeros blob and returns 0.
*/
int blob_read_link(Blob *pBlob, const char *zFilename){
  blob_zero(pBlob);
#if !defined(_WIN32)
  char zBuf[1024];
  ssize_t len = readlink(zFilename, zBuf, 1023);
  if( len < 0 ){
    fossil_panic("cannot read symbolic link %s", zFilename);
  }
  zBuf[len] = 0;   /* null-terminate */
  blob_zero(pBlob);
  blob_appendf(pBlob, "%s", zBuf);
  return len;
#else
  blob_zero(pBlob);
  return 0;
#endif
}


/*
** Write the content of a blob into a file.