1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- A D A . C O M M A N D _ L I N E --
9 -- Copyright (C) 1992-2023, Free Software Foundation, Inc. --
11 -- This specification is derived from the Ada Reference Manual for use with --
12 -- GNAT. The copyright notice above, and the license provisions that follow --
13 -- apply solely to the contents of the part following the private keyword. --
15 -- GNAT is free software; you can redistribute it and/or modify it under --
16 -- terms of the GNU General Public License as published by the Free Soft- --
17 -- ware Foundation; either version 3, or (at your option) any later ver- --
18 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
19 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
20 -- or FITNESS FOR A PARTICULAR PURPOSE. --
22 -- As a special exception under Section 7 of GPL version 3, you are granted --
23 -- additional permissions described in the GCC Runtime Library Exception, --
24 -- version 3.1, as published by the Free Software Foundation. --
26 -- You should have received a copy of the GNU General Public License and --
27 -- a copy of the GCC Runtime Library Exception along with this program; --
28 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
29 -- <http://www.gnu.org/licenses/>. --
31 -- GNAT was originally developed by the GNAT team at New York University. --
32 -- Extensive contributions were provided by Ada Core Technologies Inc. --
34 ------------------------------------------------------------------------------
36 package Ada
.Command_Line
is
39 function Argument_Count
return Natural;
40 -- If the external execution environment supports passing arguments to a
41 -- program, then Argument_Count returns the number of arguments passed to
42 -- the program invoking the function. Otherwise it return 0.
44 -- In GNAT: Corresponds to (argc - 1) in C.
46 pragma Assertion_Policy
(Pre
=> Ignore
);
47 -- We need to ignore the precondition of Argument, below, so that we don't
48 -- raise Assertion_Error. The body raises Constraint_Error. It would be
49 -- cleaner to add "or else raise Constraint_Error" to the precondition, but
50 -- SPARK does not yet support raise expressions.
52 function Argument
(Number
: Positive) return String with
53 Pre
=> Number
<= Argument_Count
;
54 -- If the external execution environment supports passing arguments to
55 -- a program, then Argument returns an implementation-defined value
56 -- corresponding to the argument at relative position Number. If Number
57 -- is outside the range 1 .. Argument_Count, then Constraint_Error is
60 -- in GNAT: Corresponds to argv [n] (for n > 0) in C.
62 function Command_Name
return String;
63 -- If the external execution environment supports passing arguments to
64 -- a program, then Command_Name returns an implementation-defined value
65 -- corresponding to the name of the command invoking the program.
66 -- Otherwise Command_Name returns the null string.
68 -- in GNAT: Corresponds to argv [0] in C.
70 type Exit_Status
is new Integer;
72 Success
: constant Exit_Status
;
73 Failure
: constant Exit_Status
;
75 procedure Set_Exit_Status
(Code
: Exit_Status
);
77 ------------------------------------
78 -- Note on Interface Requirements --
79 ------------------------------------
81 -- Services in this package are not supported during the elaboration of an
82 -- auto-initialized Stand-Alone Library.
84 -- If the main program is in Ada, this package works as specified without
85 -- any other work than the normal steps of WITH'ing the package and then
86 -- calling the desired routines.
88 -- If the main program is not in Ada, then the information must be made
89 -- available for this package to work correctly. In particular, it is
90 -- required that the global variable "gnat_argc" contain the number of
91 -- arguments, and that the global variable "gnat_argv" points to an
92 -- array of null-terminated strings, the first entry being the command
93 -- name, and the remaining entries being the command arguments.
95 -- These correspond to the normal argc/argv variables passed to a C
96 -- main program, and the following is an example of a complete C main
97 -- program that stores the required information:
99 -- main(int argc, char **argv, char **envp)
101 -- extern int gnat_argc;
102 -- extern char **gnat_argv;
103 -- extern char **gnat_envp;
113 -- The assignment statements ensure that the necessary information is
114 -- available for finding the command name and command line arguments.
117 Success
: constant Exit_Status
:= 0;
118 Failure
: constant Exit_Status
:= 1;
120 -- The following locations support the operation of the package
121 -- Ada.Command_Line.Remove, which provides facilities for logically
122 -- removing arguments from the command line. If one of the remove
123 -- procedures is called in this unit, then Remove_Args/Remove_Count
124 -- are set to indicate which arguments are removed. If no such calls
125 -- have been made, then Remove_Args is null.
127 Remove_Count
: Natural;
128 -- Number of arguments reflecting removals. Not defined unless
129 -- Remove_Args is non-null.
131 type Arg_Nums
is array (Positive range <>) of Positive;
132 type Arg_Nums_Ptr
is access Arg_Nums
;
133 -- An array that maps logical argument numbers (reflecting removal)
134 -- to physical argument numbers (e.g. if the first argument has been
135 -- removed, but not the second, then Arg_Nums (1) will be set to 2.
137 Remove_Args
: Arg_Nums_Ptr
:= null;
138 -- Left set to null if no remove calls have been made, otherwise set
139 -- to point to an appropriate mapping array. Only the first Remove_Count
140 -- elements are relevant.
142 pragma Import
(C
, Set_Exit_Status
, "__gnat_set_exit_status");
144 end Ada
.Command_Line
;