mes/posix.c

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/* -*-comment-start: "//";comment-end:""-*-
* Mes --- Maxwell Equations of Software
* Copyright © 2016 Jan Nieuwenhuizen <janneke@gnu.org>
*
* This file is part of Mes.
*
* Mes is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* Mes 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Mes. If not, see <http://www.gnu.org/licenses/>.
*/
#if !MINI_MES
#include <fcntl.h>
FILE *g_stdin;
int
getchar ()
{
return getc (g_stdin);
}
#endif
int
ungetchar (int c)
{
return ungetc (c, g_stdin);
}
int
peekchar ()
{
int c = getchar ();
ungetchar (c);
return c;
}
SCM
peek_byte ()
{
return MAKE_NUMBER (peekchar ());
}
SCM
read_byte ()
{
return MAKE_NUMBER (getchar ());
}
SCM
unread_byte (SCM i)
{
ungetchar (VALUE (i));
return i;
}
SCM
write_byte (SCM x) ///((arity . n))
{
SCM c = car (x);
SCM p = cdr (x);
int fd = 1;
if (TYPE (p) == TPAIR && TYPE (car (p)) == TNUMBER) fd = VALUE (car (p));
#if !MES_MINI
FILE *f = fd == 1 ? stdout : stderr;
fputc (VALUE (c), f);
#else
char cc = VALUE (c);
write (1, (char*)&cc, fd);
#endif
#if __GNUC__
assert (TYPE (c) == TNUMBER || TYPE (c) == TCHAR);
#endif
return c;
}
char const*
string_to_cstring (SCM s)
{
static char buf[1024];
char *p = buf;
s = STRING(s);
while (s != cell_nil)
{
*p++ = VALUE (car (s));
s = cdr (s);
}
*p = 0;
return buf;
}
SCM
getenv_ (SCM s) ///((name . "getenv"))
{
char *p = getenv (string_to_cstring (s));
return p ? MAKE_STRING (cstring_to_list (p)) : cell_f;
}
SCM
open_input_file (SCM file_name)
{
return MAKE_NUMBER (open (string_to_cstring (file_name), O_RDONLY));
}
SCM
current_input_port ()
{
return MAKE_NUMBER (fileno (g_stdin));
}
SCM
set_current_input_port (SCM port)
{
g_stdin = VALUE (port) ? fdopen (VALUE (port), "r") : stdin;
return current_input_port ();
}
SCM
force_output (SCM p) ///((arity . n))
{
int fd = 1;
if (TYPE (p) == TPAIR && TYPE (car (p)) == TNUMBER) fd = VALUE (car (p));
FILE *f = fd == 1 ? stdout : stderr;
fflush (f);
return cell_unspecified;
}