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Reference Guide
cernbuild.C File Reference

Detailed Description

View in nbviewer Open in SWAN Read data (CERN staff) from an ascii file and create a root file with a Tree.

TFile *cernbuild(Int_t getFile=0, Int_t print=1) {
Int_t Category;
UInt_t Flag;
Int_t Age;
Int_t Service;
Int_t Children;
Int_t Grade;
Int_t Hrweek;
Int_t Cost;
Char_t Division[4];
Char_t Nation[3];
//The input file cern.dat is a copy of the CERN staff data base
//from 1988
TString filename = "cernstaff.root";
TString dir = gROOT->GetTutorialDir();
FILE *fp = fopen(Form("%scernstaff.dat",dir.Data()),"r");
TFile *hfile = 0;
if (getFile) {
// if the argument getFile =1 return the file "cernstaff.root"
// if the file does not exist, it is created
if (!gSystem->AccessPathName(dir+"cernstaff.root",kFileExists)) {
hfile = TFile::Open(dir+"cernstaff.root"); //in $ROOTSYS/tutorials/tree
if (hfile) return hfile;
//otherwise try $PWD/cernstaff.root
if (!gSystem->AccessPathName("cernstaff.root",kFileExists)) {
hfile = TFile::Open("cernstaff.root"); //in current dir
if (hfile) return hfile;
//no cernstaff.root file found. Must generate it !
//generate cernstaff.root in $ROOTSYS/tutorials/tree if we have write access
printf("you must run the script in a directory with write access\n");
return 0;
hfile = TFile::Open(filename,"RECREATE");
TTree *tree = new TTree("T","CERN 1988 staff data");
char line[80];
while (fgets(line,80,fp)) {
sscanf(&line[0],"%d %d %d %d %d %d %d %d %d %s %s",
if (print) tree->Print();
delete hfile;
if (getFile) {
//we come here when the script is executed outside $ROOTSYS/tutorials/tree
return hfile;
return 0;
int Int_t
Definition: RtypesCore.h:45
char Char_t
Definition: RtypesCore.h:37
unsigned int UInt_t
Definition: RtypesCore.h:46
Option_t Option_t TPoint TPoint const char GetTextMagnitude GetFillStyle GetLineColor GetLineWidth GetMarkerStyle GetTextAlign GetTextColor GetTextSize void char Point_t Rectangle_t WindowAttributes_t Float_t Float_t Float_t Int_t Int_t UInt_t UInt_t Rectangle_t Int_t Int_t Window_t TString Int_t GCValues_t GetPrimarySelectionOwner GetDisplay GetScreen GetColormap GetNativeEvent const char const char dpyName wid window const char font_name cursor keysym reg const char only_if_exist regb h Point_t winding char text const char depth char const char Int_t count const char ColorStruct_t color const char filename
#define gROOT
Definition: TROOT.h:404
char * Form(const char *fmt,...)
Formats a string in a circular formatting buffer.
Definition: TString.cxx:2452
@ kFileExists
Definition: TSystem.h:44
@ kWritePermission
Definition: TSystem.h:46
R__EXTERN TSystem * gSystem
Definition: TSystem.h:559
A ROOT file is a suite of consecutive data records (TKey instances) with a well defined format.
Definition: TFile.h:54
static TFile * Open(const char *name, Option_t *option="", const char *ftitle="", Int_t compress=ROOT::RCompressionSetting::EDefaults::kUseCompiledDefault, Int_t netopt=0)
Create / open a file.
Definition: TFile.cxx:4019
Basic string class.
Definition: TString.h:136
const char * Data() const
Definition: TString.h:369
TString & ReplaceAll(const TString &s1, const TString &s2)
Definition: TString.h:692
TString & Append(const char *cs)
Definition: TString.h:564
virtual Bool_t AccessPathName(const char *path, EAccessMode mode=kFileExists)
Returns FALSE if one can access a file using the specified access mode.
Definition: TSystem.cxx:1296
A TTree represents a columnar dataset.
Definition: TTree.h:79
TLine * line
void Step(const gsl_rng *r, void *xp, double step_size)
Definition: tree.py:1
Rene Brun

Definition in file cernbuild.C.