guile/libguile/feature.c

/* Copyright 1995-1996,1998-2004,2006-2007,2009,2011,2013,2018
     Free Software Foundation, Inc.

   This file is part of Guile.

   Guile is free software: you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published
   by the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   Guile is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
   License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with Guile.  If not, see
   <https://www.gnu.org/licenses/>.  */




#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include <string.h>

#include "fluids.h"
#include "gsubr.h"
#include "modules.h"
#include "pairs.h"
#include "strings.h"
#include "symbols.h"
#include "variable.h"

#include "feature.h"




SCM scm_program_arguments_fluid;

static SCM features_var;

void
scm_add_feature (const char *str)
{
  SCM old = SCM_VARIABLE_REF (features_var);
  SCM new = scm_cons (scm_from_utf8_symbol (str), old);
  SCM_VARIABLE_SET (features_var, new);
}



SCM_DEFINE (scm_program_arguments, "program-arguments", 0, 0, 0, 
	    (),
	    "@deffnx {Scheme Procedure} command-line\n"
	    "Return the list of command line arguments passed to Guile, as a list of\n"
	    "strings.  The list includes the invoked program name, which is usually\n"
	    "@code{\"guile\"}, but excludes switches and parameters for command line\n"
	    "options like @code{-e} and @code{-l}.")
#define FUNC_NAME s_scm_program_arguments
{
  return scm_fluid_ref (scm_program_arguments_fluid);
}
#undef FUNC_NAME

/* Set the value returned by program-arguments, given ARGC and ARGV.

   If FIRST is non-zero, make it the first element; we do this in
   situations where other code (like getopt) has parsed out a few
   arguments, but we still want the script name to be the first
   element.  */
void
scm_set_program_arguments (int argc, char **argv, char *first)
{
  SCM args = scm_makfromstrs (argc, argv);
  if (first)
    args = scm_cons (scm_from_locale_string (first), args);
  scm_fluid_set_x (scm_program_arguments_fluid, args);
}

SCM_DEFINE (scm_set_program_arguments_scm, "set-program-arguments", 1, 0, 0, 
	    (SCM lst),
	    "Set the command line arguments to be returned by\n"
	    "@code{program-arguments} (and @code{command-line}).  @var{lst}\n"
	    "should be a list of strings, the first of which is the program\n"
	    "name (either a script name, or just @code{\"guile\"}).\n"
	    "\n"
	    "Program arguments are held in a fluid and therefore have a\n"
	    "separate value in each Guile thread.  Neither the list nor the\n"
	    "strings within it are copied, so should not be modified later.")
#define FUNC_NAME s_scm_set_program_arguments_scm
{
  return scm_fluid_set_x (scm_program_arguments_fluid, lst);
}
#undef FUNC_NAME




void
scm_init_feature()
{
  scm_program_arguments_fluid = scm_make_fluid ();

  features_var = scm_c_define ("*features*", SCM_EOL);
#ifndef _Windows
  scm_add_feature("system");
#endif
#ifndef GO32
  scm_add_feature("char-ready?");
#endif
#if SCM_USE_PTHREAD_THREADS
  scm_add_feature ("threads");
#endif

#include "feature.x"
}