//------------------------------------------------------------------------
//  A sample root macro to read a file mn54-l.tsv which is a tab-separated
//  output of SpecTech spectrography analysis program.
//
//  In ROOT, do the following:
//    root [0] .L read_tsv.C
//    root [1] read_tsv()
//
//  This creates a global histogram called h_tsv which you can then plot and
//  otherwise manipulate as any other histogram:
//    root [2] h_tsv->Draw()
//
//  Read the ROOT help web page on plotting options for TH1 (a base class
//  for TH1F used here).
//------------------------------------------------------------------------
void read_tsv()
{

  FILE *fp = fopen("mn54-l.tsv","r");
  char line[80];
  char token1[20];
  bool foundData = false;

  while (fgets(&line,80,fp)) {
    sscanf(&line[0],"%s", token1);
    if (strcmp(token1,"Data:") == 0) {
      cout << "Token1 == " << token1 << endl;
      foundData = true;
      break;
    }
  }
  if (! foundData) {
    cout << "No `Data:' token found.  Are you sure this is a tsv file?" 
	 << endl;
  }
  else {
    Float_t channel;
    Int_t   count;
    TH1F * h_tsv = new TH1F( "h_tsv", "h_tsv", 1024, -0.5, 1023.5 );
    while (fgets(&line,80,fp)) {
      cout << "Line = " << line << endl;
      sscanf(&line[0], "%f %d", &channel, &count);
      h_tsv->Fill( channel, count );
    }
  }

 End:
  fclose(fp);
}