class TEnvRec: public TObject

TEnv

The TEnv class reads a config file, by default .rootrc. Three types
of .rootrc files are read: global, user and local files. The global
file resides in $ROOTSYS/etc, the user file in ~/ and the local file
in the current working directory.
The format of the .rootrc file is similar to the .Xdefaults format:

[+]<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 resouce name.

E.g.:

Unix.Rint.Root.DynamicPath: .:$ROOTSYS/lib:~/lib
myapp.Root.Debug:  FALSE
TH.Root.Debug: YES
*.Root.MemStat: 1

<SystemName> and <ProgName> or <RootName> may be the wildcard "*".
A # in the first column starts comment line.

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:
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.