CONST char *string (in)
Info about environment variable in the form NAME=value. The string argument is in the system encoding.
Tcl_PutEnv sets an environment variable. The information is passed in a single string of the form NAME=value. This procedure is intended to be a stand-in for the UNIX putenv system call. All tcl-based applications using putenv should redefine it to Tcl_PutEnv so that they will interface properly to the Tcl runtime.