TEnv.cxx

Go to the documentation of this file.

// @(#)root/base:$Id: 0daf41ec24086ee7af29fdc2f9f2f848b150dcc8 $
// Author: Fons Rademakers   22/09/95
 
/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/
 
/** \class TEnv
\ingroup Base
 
The TEnv class reads config files, by default named `.rootrc`.
Three types of config files are read: global, user and local files. The
global file is `$ROOTSYS/etc/system<name>` (or `ROOTETCDIR/system<name>`)
the user file is `$HOME/<name>` and the local file is `./<name>`.
By setting the shell variable `ROOTENV_NO_HOME=1` the reading of
the `$HOME/<name>` resource file will be skipped. This might be useful
in case the home directory resides on an auto-mounted remote file
system and one wants to avoid this file system from being mounted.
 
The format of the `.rootrc` file is similar to the `.Xdefaults` format:
~~~ {.cpp}
  [+]<SystemName>.<RootName|ProgName>.<name>[(type)]:  <value>
~~~
Where `<SystemName>` is either Unix, WinNT, MacOS or Vms,
`<RootName>` the name as given in the TApplication ctor (or "RootApp"
in case no explicit TApplication derived object was created),
`<ProgName>` the current program name and `<name>` the resource name,
with optionally a type specification. `<value>` can be either a
string, an integer, a float/double or a boolean with the values
TRUE, FALSE, ON, OFF, YES, NO, OK, NOT. Booleans will be returned as
an integer 0 or 1. The options [+] allows the concatenation of
values to the same resource name.
 
E.g.:
~~~ {.cpp}
  Unix.Rint.Root.DynamicPath: .:$(ROOTSYS)/lib:~/lib
  myapp.Root.Debug:  FALSE
  TH.Root.Debug: YES
  *.Root.ObjStat: 1
~~~
`<SystemName>` and `<ProgName>` or `<RootName>` may be the wildcard "*".
A # in the first column starts comment line.
 
Note that the environment variables (like $ROOTSYS) need to be
surrounded in parentheses in order to be expanded.
 
For the currently defined resources (and their default values) see
`$ROOTSYS/etc/system.rootrc`.
 
Note that the .rootrc config files contain the config for all ROOT
based applications.
 
To add new entries to a TEnv:
~~~ {.cpp}
TEnv env(".myfile");
env.SetValue("myname","value");
env.SaveLevel(kEnvLocal);
~~~
All new entries will be saved in the file corresponding to the
first SaveLevel() command.  If Save() is used, new entries go
into the local file by default.
*/
 
#include "RConfigure.h"
 
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cctype>
 
#include "strlcpy.h"
#include "TEnv.h"
#include "TROOT.h"
#include "TSystem.h"
#include "THashList.h"
#include "TError.h"
 
 
TEnv *gEnv;  // main environment created in TROOT
 
 
static struct BoolNameTable_t {
   const char *fName;
   Int_t       fValue;
} gBoolNames[]= {
   { "TRUE",  1 },
   { "FALSE", 0 },
   { "ON",    1 },
   { "OFF",   0 },
   { "YES",   1 },
   { "NO",    0 },
   { "OK",    1 },
   { "NOT",   0 },
   { nullptr, 0 }
};
 
 
/** \class TEnvParser
TEnv Parser.
*/
 
class TEnvParser {
 
private:
   FILE    *fIfp;
 
protected:
   TEnv    *fEnv;
 
public:
   TEnvParser(TEnv *e, FILE *f) : fIfp(f), fEnv(e) { }
   virtual ~TEnvParser() { }
   virtual void KeyValue(const TString&, const TString&, const TString&) { }
   virtual void Char(Int_t) { }
   void Parse();
};
 
////////////////////////////////////////////////////////////////////////////////
/// Parse a line of the env file and create an entry in the resource
/// dictionary (i.e. add a KeyValue pair).
 
void TEnvParser::Parse()
{
   TString name(1024);
   TString type(1024);
   TString value(1024);
   int c, state = 0;
 
   while ((c = fgetc(fIfp)) != EOF) {
      if (c == 13)        // ignore CR
         continue;
      if (c == '\n') {
         state = 0;
         if (name.Length() > 0) {
            KeyValue(name, value, type);
            name.Clear();
            value.Clear();
            type.Clear();
         }
         Char(c);
         continue;
      }
      switch (state) {
      case 0:             // start of line
         switch (c) {
         case ' ':
         case '\t':
            break;
         case '#':
            state = 1;
            break;
         default:
            state = 2;
            break;
         }
         break;
 
      case 1:             // comment
         break;
 
      case 2:             // name
         switch (c) {
         case ' ':
         case '\t':
         case ':':
            state = 3;
            break;
         case '(':
            state = 7;
            break;
         default:
            break;
         }
         break;
 
      case 3:             // ws before value
         if (c != ' ' && c != '\t')
            state = 4;
         break;
 
      case 4:             // value
         break;
 
      case 5:             // type
         if (c == ')')
            state = 6;
         break;
 
      case 6:             // optional ':'
         state = (c == ':') ? 3 : 4;
         break;
 
      case 7:
         state = (c == ')') ? 6 : 5;
         break;
 
      }
      switch (state) {
      case 2:
         name.Append(c);
         break;
      case 4:
         value.Append(c);
         break;
      case 5:
         type.Append(c);
         break;
      }
      if (state != 4)
         Char(c);
   }
   // In case EOF is reach before '\n'
   if (name.Length() > 0) {
      KeyValue(name, value, type);
      name.Clear();
      value.Clear();
      type.Clear();
   }
}
 
/** \class TReadEnvParser
*/
 
class TReadEnvParser : public TEnvParser {
 
private:
   EEnvLevel fLevel;
 
public:
   TReadEnvParser(TEnv *e, FILE *f, EEnvLevel l) : TEnvParser(e, f), fLevel(l) {}
   void KeyValue(const TString &name, const TString &value, const TString &type) override
      { fEnv->SetValue(name, value, fLevel, type); }
};
 
/** \class TWriteEnvParser
*/
 
class TWriteEnvParser : public TEnvParser {
 
private:
   FILE *fOfp;
 
public:
   TWriteEnvParser(TEnv *e, FILE *f, FILE *of) : TEnvParser(e, f), fOfp(of) {}
   void KeyValue(const TString &name, const TString &value, const TString &type) override;
   void Char(Int_t c) override { fputc(c, fOfp); }
};
 
////////////////////////////////////////////////////////////////////////////////
/// Write resources out to a new file.
 
void TWriteEnvParser::KeyValue(const TString &name, const TString &value,
                               const TString &)
{
   TEnvRec *er = fEnv->Lookup(name);
   if (er && er->fModified) {
      er->fModified = kFALSE;
      fprintf(fOfp, "%s", er->fValue.Data());
   } else
      fprintf(fOfp, "%s", value.Data());
}
 
 
/** \class TEnvRec
*/
 
////////////////////////////////////////////////////////////////////////////////
/// Ctor of a single resource.
 
TEnvRec::TEnvRec(const char *n, const char *v, const char *t, EEnvLevel l)
   : fName(n), fType(t), fLevel(l)
{
   fValue = ExpandValue(v);
   fModified = (l == kEnvChange);
}
 
////////////////////////////////////////////////////////////////////////////////
/// TNamed destructor.
 
TEnvRec::~TEnvRec()
{
   // Required since we overload TObject::Hash.
   ROOT::CallRecursiveRemoveIfNeeded(*this);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Change the value of a resource.
 
void TEnvRec::ChangeValue(const char *v, const char *, EEnvLevel l,
                          Bool_t append, Bool_t ignoredup)
{
   if (l != kEnvChange && fLevel == l && !append) {
      // use global Warning() since interpreter might not yet be initialized
      // at this stage (called from TROOT ctor)
      if (fValue != v && !ignoredup)
         ::Warning("TEnvRec::ChangeValue",
           "duplicate entry <%s=%s> for level %d; ignored", fName.Data(), v, l);
      return;
   }
   if (!append) {
      if (fValue != v) {
         if (l == kEnvChange)
            fModified = kTRUE;
         else
            fModified = kFALSE;
         fLevel = l;
         fValue = ExpandValue(v);
      }
   } else {
      if (l == kEnvChange)
         fModified = kTRUE;
      fLevel = l;
      fValue += " ";
      fValue += ExpandValue(v);
   }
}
 
////////////////////////////////////////////////////////////////////////////////
/// Comparison function for resources.
 
Int_t TEnvRec::Compare(const TObject *op) const
{
   return fName.CompareTo(((TEnvRec*)op)->fName);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Replace all $(XXX) strings by the value defined in the shell
/// (obtained via TSystem::Getenv()).
 
TString TEnvRec::ExpandValue(const char *value)
{
   const char *vv;
   char *v, *vorg = StrDup(value);
   v = vorg;
 
   char *s1, *s2;
   int len = 0;
   while ((s1 = (char*)strstr(v, "$("))) {
      s1 += 2;
      s2 = (char*)strchr(s1, ')');
      if (!s2) {
         len = 0;
         break;
      }
      *s2 = 0;
      vv = gSystem->Getenv(s1);
      if (vv) len += strlen(vv);
      *s2 = ')';
      v = s2 + 1;
   }
 
   if (!len) {
      delete [] vorg;
      return TString(value);
   }
 
   v = vorg;
   int nch = strlen(v) + len;
   char *nv = new char[nch];
   *nv = 0;
 
   while ((s1 = (char*)strstr(v, "$("))) {
      *s1 = 0;
      strlcat(nv, v,nch);
      *s1 = '$';
      s1 += 2;
      s2 = (char*)strchr(s1, ')');
      *s2 = 0;
      vv = gSystem->Getenv(s1);
      if (vv) strlcat(nv, vv,nch);
      *s2 = ')';
      v = s2 + 1;
   }
 
   if (*v) strlcat(nv, v,nch);
 
   TString val = nv;
   delete [] nv;
   delete [] vorg;
 
   return val;
}
 
ClassImp(TEnv);
 
////////////////////////////////////////////////////////////////////////////////
/// Create a resource table and read the (possibly) three resource files,
/// i.e.\ `$ROOTSYS/etc/system<name>` (or `ROOTETCDIR/system<name>`),
/// `$HOME/<name>` and `$PWD/<name>`.
/// ROOT always reads ".rootrc" (in TROOT::InitSystem()). You can
/// read additional user defined resource files by creating additional TEnv
/// objects. By setting the shell variable ROOTENV_NO_HOME=1 the reading of
/// the `$HOME/<name>` resource file will be skipped. This might be useful in
/// case the home directory resides on an auto-mounted remote file system
/// and one wants to avoid the file system from being mounted.
 
TEnv::TEnv(const char *name)
{
   fIgnoreDup = kFALSE;
 
   if (!name || !name[0] || !gSystem)
      fTable = nullptr;
   else {
      fTable  = new THashList(1000);
      fRcName = name;
 
      TString sname = "system";
      sname += name;
      char *s = gSystem->ConcatFileName(TROOT::GetEtcDir(), sname);
      ReadFile(s, kEnvGlobal);
      delete [] s;
      if (!gSystem->Getenv("ROOTENV_NO_HOME")) {
         s = gSystem->ConcatFileName(gSystem->HomeDirectory(), name);
         ReadFile(s, kEnvUser);
         delete [] s;
         if (strcmp(gSystem->HomeDirectory(), gSystem->WorkingDirectory()))
            ReadFile(name, kEnvLocal);
      } else
         ReadFile(name, kEnvLocal);
   }
}
 
////////////////////////////////////////////////////////////////////////////////
/// Delete the resource table.
 
TEnv::~TEnv()
{
   if (fTable) {
      fTable->Delete();
      SafeDelete(fTable);
   }
}
 
////////////////////////////////////////////////////////////////////////////////
/// Returns the character value for a named resource.
 
const char *TEnv::Getvalue(const char *name) const
{
   Bool_t haveProgName = kFALSE;
   if (gProgName && strlen(gProgName) > 0)
      haveProgName = kTRUE;
 
   TString aname;
   TEnvRec *er = nullptr;
   if (haveProgName && gSystem && gProgName) {
      aname = gSystem->GetName(); aname += "."; aname += gProgName;
      aname += "."; aname += name;
      er = Lookup(aname);
   }
   if (er == nullptr && gSystem && gROOT) {
      aname = gSystem->GetName(); aname += "."; aname += gROOT->GetName();
      aname += "."; aname += name;
      er = Lookup(aname);
   }
   if (er == nullptr && gSystem) {
      aname = gSystem->GetName(); aname += ".*."; aname += name;
      er = Lookup(aname);
   }
   if (er == nullptr && haveProgName && gProgName) {
      aname = gProgName; aname += "."; aname += name;
      er = Lookup(aname);
   }
   if (er == nullptr && gROOT) {
      aname = gROOT->GetName(); aname += "."; aname += name;
      er = Lookup(aname);
   }
   if (er == nullptr) {
      aname = "*.*."; aname += name;
      er = Lookup(aname);
   }
   if (er == nullptr) {
      aname = "*."; aname += name;
      er = Lookup(aname);
   }
   if (er == nullptr) {
      er = Lookup(name);
   }
   if (er == nullptr)
      return nullptr;
   return er->fValue;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Returns the integer value for a resource. If the resource is not found
/// return the default value.
 
Int_t TEnv::GetValue(const char *name, Int_t dflt) const
{
   const char *cp = TEnv::Getvalue(name);
   if (cp) {
      char buf2[512], *cp2 = buf2;
 
      while (isspace((int)*cp))
         cp++;
      if (*cp) {
         BoolNameTable_t *bt;
         if (isdigit((int)*cp) || *cp == '-' || *cp == '+')
            return atoi(cp);
         while (isalpha((int)*cp))
            *cp2++ = toupper((int)*cp++);
         *cp2 = 0;
         for (bt = gBoolNames; bt->fName; bt++)
            if (strcmp(buf2, bt->fName) == 0)
               return bt->fValue;
      }
   }
   return dflt;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Returns the double value for a resource. If the resource is not found
/// return the default value.
 
Double_t TEnv::GetValue(const char *name, Double_t dflt) const
{
   const char *cp = TEnv::Getvalue(name);
   if (cp) {
      char *endptr;
      Double_t val = strtod(cp, &endptr);
      if (val == 0.0 && cp == endptr)
         return dflt;
      return val;
   }
   return dflt;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Returns the character value for a named resource. If the resource is
/// not found the default value is returned.
 
const char *TEnv::GetValue(const char *name, const char *dflt) const
{
   const char *cp = TEnv::Getvalue(name);
   if (cp)
      return cp;
   return dflt;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Loop over all resource records and return the one with name.
/// Return 0 in case name is not in the resource table.
 
TEnvRec *TEnv::Lookup(const char *name) const
{
   if (!fTable) return nullptr;
   return (TEnvRec*) fTable->FindObject(name);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Print all resources or the global, user or local resources separately.
 
void TEnv::Print(Option_t *opt) const
{
   if (!opt || !opt[0]) {
      PrintEnv();
      return;
   }
 
   if (!strcmp(opt, "global"))
      PrintEnv(kEnvGlobal);
   if (!strcmp(opt, "user"))
      PrintEnv(kEnvUser);
   if (!strcmp(opt, "local"))
      PrintEnv(kEnvLocal);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Print all resources for a certain level (global, user, local, changed).
 
void TEnv::PrintEnv(EEnvLevel level) const
{
   if (!fTable) return;
 
   TIter next(fTable);
   TEnvRec *er;
   static const char *lc[] = { "Global", "User", "Local", "Changed", "All" };
 
   while ((er = (TEnvRec*) next()))
      if (er->fLevel == level || level == kEnvAll)
         Printf("%-25s %-30s [%s]", TString::Format("%s:", er->fName.Data()).Data(),
                er->fValue.Data(), lc[er->fLevel]);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Read and parse the resource file for a certain level.
/// Returns -1 on case of error, 0 in case of success.
 
Int_t TEnv::ReadFile(const char *fname, EEnvLevel level)
{
   if (!fname || !fname[0]) {
      Error("ReadFile", "no file name specified");
      return -1;
   }
 
   FILE *ifp;
   if ((ifp = fopen(fname, "r"))) {
      TReadEnvParser rp(this, ifp, level);
      rp.Parse();
      fclose(ifp);
      return 0;
   }
 
   // no Error() here since we are allowed to try to read from a non-existing
   // file (like ./.rootrc, $HOME/.rootrc, etc.)
   return -1;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Write resource records to file fname for a certain level. Use
/// level kEnvAll to write all resources. Returns -1 on case of error,
/// 0 in case of success.
 
Int_t TEnv::WriteFile(const char *fname, EEnvLevel level)
{
   if (!fname || !fname[0]) {
      Error("WriteFile", "no file name specified");
      return -1;
   }
 
   if (!fTable) {
      Error("WriteFile", "TEnv table is empty");
      return -1;
   }
 
   FILE *ofp;
   if ((ofp = fopen(fname, "w"))) {
      TIter next(fTable);
      TEnvRec *er;
      while ((er = (TEnvRec*) next()))
         if (er->fLevel == level || level == kEnvAll)
            fprintf(ofp, "%-40s %s\n", TString::Format("%s:", er->fName.Data()).Data(),
                    er->fValue.Data());
      fclose(ofp);
      return 0;
   }
 
   Error("WriteFile", "cannot open %s for writing", fname);
   return -1;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Write the resource files for each level. The new files have the same
/// name as the original files. The old files are renamed to *.bak.
 
void TEnv::Save()
{
   if (fRcName == "") {
      Error("Save", "no resource file name specified");
      return;
   }
 
   SaveLevel(kEnvLocal);  // Be default, new items will be put into Local.
   SaveLevel(kEnvUser);
   SaveLevel(kEnvGlobal);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Write the resource file for a certain level.
 
void TEnv::SaveLevel(EEnvLevel level)
{
   if (fRcName == "") {
      Error("SaveLevel", "no resource file name specified");
      return;
   }
 
   if (!fTable) {
      Error("SaveLevel", "TEnv table is empty");
      return;
   }
 
   TString   rootrcdir;
   FILE     *ifp, *ofp;
 
   if (level == kEnvGlobal) {
 
      TString sname = "system";
      sname += fRcName;
      char *s = gSystem->ConcatFileName(TROOT::GetEtcDir(), sname);
      rootrcdir = s;
      delete [] s;
   } else if (level == kEnvUser) {
      char *s = gSystem->ConcatFileName(gSystem->HomeDirectory(), fRcName);
      rootrcdir = s;
      delete [] s;
   } else if (level == kEnvLocal)
      rootrcdir = fRcName;
   else
      return;
 
   if ((ofp = fopen(TString::Format("%s.new", rootrcdir.Data()).Data(), "w"))) {
      ifp = fopen(rootrcdir.Data(), "r");
      if (ifp == nullptr) {     // try to create file
         ifp = fopen(rootrcdir.Data(), "w");
         if (ifp) {
            fclose(ifp);
            ifp = nullptr;
         }
      }
      if (ifp || (ifp = fopen(rootrcdir.Data(), "r"))) {
         TWriteEnvParser wp(this, ifp, ofp);
         wp.Parse();
 
         TIter next(fTable);
         TEnvRec *er;
         while ((er = (TEnvRec*) next())) {
            if (er->fModified) {
 
               // If it doesn't have a level yet, make it this one.
               if (er->fLevel == kEnvChange) er->fLevel = level;
               if (er->fLevel == level) {
                  er->fModified = kFALSE;
                  fprintf(ofp, "%-40s %s\n", TString::Format("%s:", er->fName.Data()).Data(),
                          er->fValue.Data());
               }
            }
         }
         fclose(ifp);
         fclose(ofp);
         gSystem->Rename(rootrcdir.Data(), TString::Format("%s.bak", rootrcdir.Data()).Data());
         gSystem->Rename(TString::Format("%s.new", rootrcdir.Data()).Data(), rootrcdir.Data());
         return;
      }
      fclose(ofp);
   } else
      Error("SaveLevel", "cannot write to file %s", rootrcdir.Data());
}
 
////////////////////////////////////////////////////////////////////////////////
/// Set the value of a resource or create a new resource.
 
void TEnv::SetValue(const char *name, const char *value, EEnvLevel level,
                    const char *type)
{
   if (!fTable)
      fTable  = new THashList(1000);
 
   const char *nam = name;
   Bool_t append = kFALSE;
   if (name[0] == '+') {
      nam    = &name[1];
      append = kTRUE;
   }
 
   TEnvRec *er = Lookup(nam);
   if (er)
      er->ChangeValue(value, type, level, append, fIgnoreDup);
   else
      fTable->Add(new TEnvRec(nam, value, type, level));
}
 
////////////////////////////////////////////////////////////////////////////////
/// Set the value of a resource or create a new resource.
/// Use this method to set a resource like, "name=val".
/// If just "name" is given it will be interpreted as "name=1".
 
void TEnv::SetValue(const char *name, EEnvLevel level)
{
   TString buf = name;
   int l = buf.Index("=");
   if (l > 0) {
      TString nm  = buf(0, l);
      TString val = buf(l+1, buf.Length());
      SetValue(nm, val, level);
   } else
      SetValue(name, "1", level);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Set or create an integer resource value.
 
void TEnv::SetValue(const char *name, Int_t value)
{
   SetValue(name, TString::Format("%d", value).Data());
}
 
////////////////////////////////////////////////////////////////////////////////
/// Set or create a double resource value.
 
void TEnv::SetValue(const char *name, Double_t value)
{
   SetValue(name, TString::Format("%g", value).Data());
}
 
////////////////////////////////////////////////////////////////////////////////
/// If set to true, no warnings in case of duplicates are issued.
/// Returns previous value.
 
Bool_t TEnv::IgnoreDuplicates(Bool_t ignore)
{
   Bool_t ret = fIgnoreDup;
   fIgnoreDup = ignore;
   return ret;
}