* ports.h (scm_port): make read_pos a pointer to const.
[bpt/guile.git] / libguile / fports.h
1 /* classes: h_files */
2
3 #ifndef FPORTSH
4 #define FPORTSH
5 /* Copyright (C) 1995,1996,1997,1998 Free Software Foundation, Inc.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2, or (at your option)
10 * any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this software; see the file COPYING. If not, write to
19 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
20 * Boston, MA 02111-1307 USA
21 *
22 * As a special exception, the Free Software Foundation gives permission
23 * for additional uses of the text contained in its release of GUILE.
24 *
25 * The exception is that, if you link the GUILE library with other files
26 * to produce an executable, this does not by itself cause the
27 * resulting executable to be covered by the GNU General Public License.
28 * Your use of that executable is in no way restricted on account of
29 * linking the GUILE library code into it.
30 *
31 * This exception does not however invalidate any other reasons why
32 * the executable file might be covered by the GNU General Public License.
33 *
34 * This exception applies only to the code released by the
35 * Free Software Foundation under the name GUILE. If you copy
36 * code from other Free Software Foundation releases into a copy of
37 * GUILE, as the General Public License permits, the exception does
38 * not apply to the code that you add in this way. To avoid misleading
39 * anyone as to the status of such modified files, you must delete
40 * this exception notice from them.
41 *
42 * If you write modifications of your own for GUILE, it is your choice
43 * whether to permit this exception to apply to your modifications.
44 * If you do not wish that, delete this exception notice. */
45 \f
46
47 #include "libguile/__scm.h"
48
49 #include "libguile/ports.h"
50
51 \f
52
53 /* struct allocated for each buffered FPORT. */
54 struct scm_fport {
55 int fdes; /* file descriptor. */
56
57 /* if fdes supports random access (i.e., can change position using lseek)
58 then read/write ports reset the write position to account for buffered
59 chars whenever switching from reading to writing. it wouldn't need to
60 be done if fdes is in append mode, but that can be changed at any time
61 and it would be more work to check for it. */
62 int random; /* whether fdes supports random-access. */
63 };
64
65 #define SCM_FSTREAM(x) ((struct scm_fport *) SCM_STREAM (x))
66 #define SCM_FPORT_FDES(x) (SCM_FSTREAM (x)->fdes)
67
68 #define SCM_FPORTP(x) (SCM_TYP16S(x)==scm_tc7_port)
69 #define SCM_OPFPORTP(x) (((0xfeff | SCM_OPN) & SCM_CAR(x))==(scm_tc7_port | SCM_OPN))
70 #define SCM_OPINFPORTP(x) (((0xfeff | SCM_OPN | SCM_RDNG) & SCM_CAR(x))==(scm_tc7_port | SCM_OPN | SCM_RDNG))
71 #define SCM_OPOUTFPORTP(x) (((0xfeff | SCM_OPN | SCM_WRTNG) & SCM_CAR(x))==(scm_tc7_port | SCM_OPN | SCM_WRTNG))
72
73 /* test whether fdes supports random access. */
74 #define SCM_FDES_RANDOM_P(fdes) ((lseek (fdes, 0, SEEK_CUR) == -1) ? 0 : 1)
75
76 extern scm_ptobfuns scm_fptob;
77
78 \f
79 extern SCM scm_setbuf0 (SCM port);
80 extern SCM scm_setvbuf (SCM port, SCM mode, SCM size);
81 extern void scm_setfileno (FILE *fs, int fd);
82 extern void scm_evict_ports (int fd);
83 extern SCM scm_open_file (SCM filename, SCM modes);
84 extern SCM scm_fdes_to_port (int fdes, char *mode, SCM name);
85 extern char *scm_fport_drain_input (SCM port, int *count_return);
86 extern void scm_init_fports SCM_P ((void));
87
88 #endif /* FPORTSH */