Bus error (core dumped) occurs in my program, and the error is locked in the fopen part of the code

void dipget(int icdp, int nti, float *dip, char * tanpath)
{
  FILE * dfile;
  char *filename;

  printf("Choose %d from %s\n",icdp, tanpath);
  sprintf(filename, "%s%d.x.dat",tanpath, icdp);
  printf("Open file: %s \n", filename);

  if((dfile = fopen(filename,"rb"))==NULL) // Bus error
  {
    printf("\n Open %s File error\n",filename);
    exit(EXIT_FAILURE);
  }
  fread(dip, sizeof(float), nti, dfile);
  fclose(dfile);
}

Here, you only need to make one step of modification to solve the problem. The reason is very simple. Before using sprintf, you need to allocate a buffer space to it

  char *filename;
  Change to
  char filename[200];