Tcl_FindExecutable(3)       Tcl Library Procedures       Tcl_FindExecutable(3)


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

       #include <tcl.h>


       CONST char *

       char   *argv0   (in)      The first command-line argument to  the  pro-
                                 gram, 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 executable's path name is needed for several
       purposes in Tcl.  For example, it is needed on some  platforms  in  the
       implementation  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.  It is important not  to  change  the  working  directory
       before  the  invocation.   Tcl_FindExecutable uses argv0 along with the
       PATH environment variable to find the application's executable, if pos-
       sible.  If it fails to find the binary, then future calls to info name-
       ofexecutable 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  nameofexe-
       cutable  command.   NULL is returned if the internal full path name has
       not been computed or unknown.

       binary, executable file

Tcl                                   8.1                Tcl_FindExecutable(3)