The package Ada.Command_Line
provides access to the command-line
arguments and program name. In order for this interface to operate
correctly, the two variables
int gnat_argc; char **gnat_argv;
are declared in one of the GNAT library routines. These variables must
be set from the actual argc
and argv
values passed to the
main program. With no ‘n’ present, gnatbind
generates the C main program to automatically set these variables.
If the ‘n’ switch is used, there is no automatic way to
set these variables. If they are not set, the procedures in
Ada.Command_Line
will not be available, and any attempt to use
them will raise Constraint_Error
. If command line access is
required, your main program must set gnat_argc
and
gnat_argv
from the argc
and argv
values passed to
it.