Tcl_FindExecutable,  Tcl_GetNameOfExecutable - identify or
       return the name of the binary file containing the applica­


       #include <tcl.h>


       CONST char *


       char   *argv0   (in)      The  first command-line argument
                                 to the program, which gives  the
                                 application's name.


       The  Tcl_FindExecutable  procedure  computes the full path
       name of the executable file from which the application was
       invoked  and  saves  it  for Tcl's internal use.  The exe­
       cutable's path name is needed for several purposes in Tcl.
       For  example, it is needed on some platforms in the imple­
       mentation of the load command.  It is also returned by the
       info nameofexecutable command.

       On  UNIX  platforms this procedure is typically invoked as
       the very first thing in the  application's  main  program;
       it  must  be passed argv[0] as its argument.  Tcl_FindExe­
       cutable uses argv0 along with the PATH  environment  vari­
       able  to  find  the application's executable, if possible.
       If it fails to find the binary, then future calls to  info
       nameofexecutable will return an empty string.

       Tcl_GetNameOfExecutable  simply  returns  a pointer to the
       internal full path name of the executable file as computed
       by  Tcl_FindExecutable.   This procedure call is the C API
       equivalent to the info nameofexecutable command.  NULL  is
       returned  if the internal full path name has not been com­
       puted or unknown.


       binary, executable file