Changed license terms to the plain LGPL thru-out.
[bpt/guile.git] / libguile / fports.c
1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002 Free Software Foundation, Inc.
2 *
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public
5 * License as published by the Free Software Foundation; either
6 * version 2.1 of the License, or (at your option) any later version.
7 *
8 * This library is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * Lesser General Public License for more details.
12 *
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16 */
17
18
19 \f
20 #if HAVE_CONFIG_H
21 # include <config.h>
22 #endif
23
24 #include <stdio.h>
25 #include <fcntl.h>
26 #include "libguile/_scm.h"
27 #include "libguile/strings.h"
28 #include "libguile/validate.h"
29 #include "libguile/gc.h"
30
31 #include "libguile/fports.h"
32
33 #ifdef HAVE_STRING_H
34 #include <string.h>
35 #endif
36 #ifdef HAVE_UNISTD_H
37 #include <unistd.h>
38 #else
39 size_t fwrite ();
40 #endif
41 #ifdef HAVE_IO_H
42 #include <io.h>
43 #endif
44 #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
45 #include <sys/stat.h>
46 #endif
47
48 #include <errno.h>
49
50 #include "libguile/iselect.h"
51
52 /* Some defines for Windows (native port, not Cygwin). */
53 #ifdef __MINGW32__
54 # include <sys/stat.h>
55 # include <winsock2.h>
56 # define ftruncate(fd, size) chsize (fd, size)
57 #endif /* __MINGW32__ */
58
59
60 scm_t_bits scm_tc16_fport;
61
62
63 /* default buffer size, used if the O/S won't supply a value. */
64 static const size_t default_buffer_size = 1024;
65
66 /* create FPORT buffer with specified sizes (or -1 to use default size or
67 0 for no buffer. */
68 static void
69 scm_fport_buffer_add (SCM port, long read_size, int write_size)
70 #define FUNC_NAME "scm_fport_buffer_add"
71 {
72 scm_t_port *pt = SCM_PTAB_ENTRY (port);
73
74 if (read_size == -1 || write_size == -1)
75 {
76 size_t default_size;
77 #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
78 struct stat st;
79 scm_t_fport *fp = SCM_FSTREAM (port);
80
81 default_size = (fstat (fp->fdes, &st) == -1) ? default_buffer_size
82 : st.st_blksize;
83 #else
84 default_size = default_buffer_size;
85 #endif
86 if (read_size == -1)
87 read_size = default_size;
88 if (write_size == -1)
89 write_size = default_size;
90 }
91
92 if (SCM_INPUT_PORT_P (port) && read_size > 0)
93 {
94 pt->read_buf = scm_gc_malloc (read_size, "port buffer");
95 pt->read_pos = pt->read_end = pt->read_buf;
96 pt->read_buf_size = read_size;
97 }
98 else
99 {
100 pt->read_pos = pt->read_buf = pt->read_end = &pt->shortbuf;
101 pt->read_buf_size = 1;
102 }
103
104 if (SCM_OUTPUT_PORT_P (port) && write_size > 0)
105 {
106 pt->write_buf = scm_gc_malloc (write_size, "port buffer");
107 pt->write_pos = pt->write_buf;
108 pt->write_buf_size = write_size;
109 }
110 else
111 {
112 pt->write_buf = pt->write_pos = &pt->shortbuf;
113 pt->write_buf_size = 1;
114 }
115
116 pt->write_end = pt->write_buf + pt->write_buf_size;
117 if (read_size > 0 || write_size > 0)
118 SCM_SET_CELL_WORD_0 (port, SCM_CELL_WORD_0 (port) & ~SCM_BUF0);
119 else
120 SCM_SET_CELL_WORD_0 (port, SCM_CELL_WORD_0 (port) | SCM_BUF0);
121 }
122 #undef FUNC_NAME
123
124 SCM_DEFINE (scm_setvbuf, "setvbuf", 2, 1, 0,
125 (SCM port, SCM mode, SCM size),
126 "Set the buffering mode for @var{port}. @var{mode} can be:\n"
127 "@table @code\n"
128 "@item _IONBF\n"
129 "non-buffered\n"
130 "@item _IOLBF\n"
131 "line buffered\n"
132 "@item _IOFBF\n"
133 "block buffered, using a newly allocated buffer of @var{size} bytes.\n"
134 "If @var{size} is omitted, a default size will be used.\n"
135 "@end table")
136 #define FUNC_NAME s_scm_setvbuf
137 {
138 int cmode;
139 long csize;
140 scm_t_port *pt;
141
142 port = SCM_COERCE_OUTPORT (port);
143
144 SCM_VALIDATE_OPFPORT (1,port);
145 SCM_VALIDATE_INUM_COPY (2,mode,cmode);
146 if (cmode != _IONBF && cmode != _IOFBF && cmode != _IOLBF)
147 scm_out_of_range (FUNC_NAME, mode);
148
149 if (cmode == _IOLBF)
150 {
151 SCM_SET_CELL_WORD_0 (port, SCM_CELL_WORD_0 (port) | SCM_BUFLINE);
152 cmode = _IOFBF;
153 }
154 else
155 {
156 SCM_SET_CELL_WORD_0 (port, SCM_CELL_WORD_0 (port) ^ SCM_BUFLINE);
157 }
158
159 if (SCM_UNBNDP (size))
160 {
161 if (cmode == _IOFBF)
162 csize = -1;
163 else
164 csize = 0;
165 }
166 else
167 {
168 SCM_VALIDATE_INUM_COPY (3,size,csize);
169 if (csize < 0 || (cmode == _IONBF && csize > 0))
170 scm_out_of_range (FUNC_NAME, size);
171 }
172
173 pt = SCM_PTAB_ENTRY (port);
174
175 /* silently discards buffered and put-back chars. */
176 if (pt->read_buf == pt->putback_buf)
177 {
178 pt->read_buf = pt->saved_read_buf;
179 pt->read_pos = pt->saved_read_pos;
180 pt->read_end = pt->saved_read_end;
181 pt->read_buf_size = pt->saved_read_buf_size;
182 }
183 if (pt->read_buf != &pt->shortbuf)
184 scm_gc_free (pt->read_buf, pt->read_buf_size, "port buffer");
185 if (pt->write_buf != &pt->shortbuf)
186 scm_gc_free (pt->write_buf, pt->write_buf_size, "port buffer");
187
188 scm_fport_buffer_add (port, csize, csize);
189 return SCM_UNSPECIFIED;
190 }
191 #undef FUNC_NAME
192
193 /* Move ports with the specified file descriptor to new descriptors,
194 * resetting the revealed count to 0.
195 */
196
197 void
198 scm_evict_ports (int fd)
199 {
200 long i;
201
202 for (i = 0; i < scm_i_port_table_size; i++)
203 {
204 SCM port = scm_i_port_table[i]->port;
205
206 if (SCM_FPORTP (port))
207 {
208 scm_t_fport *fp = SCM_FSTREAM (port);
209
210 if (fp->fdes == fd)
211 {
212 fp->fdes = dup (fd);
213 if (fp->fdes == -1)
214 scm_syserror ("scm_evict_ports");
215 scm_set_port_revealed_x (port, SCM_MAKINUM (0));
216 }
217 }
218 }
219 }
220
221
222 SCM_DEFINE (scm_file_port_p, "file-port?", 1, 0, 0,
223 (SCM obj),
224 "Determine whether @var{obj} is a port that is related to a file.")
225 #define FUNC_NAME s_scm_file_port_p
226 {
227 return SCM_BOOL (SCM_FPORTP (obj));
228 }
229 #undef FUNC_NAME
230
231
232 /* scm_open_file
233 * Return a new port open on a given file.
234 *
235 * The mode string must match the pattern: [rwa+]** which
236 * is interpreted in the usual unix way.
237 *
238 * Return the new port.
239 */
240 SCM_DEFINE (scm_open_file, "open-file", 2, 0, 0,
241 (SCM filename, SCM mode),
242 "Open the file whose name is @var{filename}, and return a port\n"
243 "representing that file. The attributes of the port are\n"
244 "determined by the @var{mode} string. The way in which this is\n"
245 "interpreted is similar to C stdio. The first character must be\n"
246 "one of the following:\n"
247 "@table @samp\n"
248 "@item r\n"
249 "Open an existing file for input.\n"
250 "@item w\n"
251 "Open a file for output, creating it if it doesn't already exist\n"
252 "or removing its contents if it does.\n"
253 "@item a\n"
254 "Open a file for output, creating it if it doesn't already\n"
255 "exist. All writes to the port will go to the end of the file.\n"
256 "The \"append mode\" can be turned off while the port is in use\n"
257 "@pxref{Ports and File Descriptors, fcntl}\n"
258 "@end table\n"
259 "The following additional characters can be appended:\n"
260 "@table @samp\n"
261 "@item +\n"
262 "Open the port for both input and output. E.g., @code{r+}: open\n"
263 "an existing file for both input and output.\n"
264 "@item 0\n"
265 "Create an \"unbuffered\" port. In this case input and output\n"
266 "operations are passed directly to the underlying port\n"
267 "implementation without additional buffering. This is likely to\n"
268 "slow down I/O operations. The buffering mode can be changed\n"
269 "while a port is in use @pxref{Ports and File Descriptors,\n"
270 "setvbuf}\n"
271 "@item l\n"
272 "Add line-buffering to the port. The port output buffer will be\n"
273 "automatically flushed whenever a newline character is written.\n"
274 "@end table\n"
275 "In theory we could create read/write ports which were buffered\n"
276 "in one direction only. However this isn't included in the\n"
277 "current interfaces. If a file cannot be opened with the access\n"
278 "requested, @code{open-file} throws an exception.")
279 #define FUNC_NAME s_scm_open_file
280 {
281 SCM port;
282 int fdes;
283 int flags = 0;
284 char *file;
285 char *md;
286 char *ptr;
287
288 SCM_VALIDATE_STRING (1, filename);
289 SCM_VALIDATE_STRING (2, mode);
290
291 file = SCM_STRING_CHARS (filename);
292 md = SCM_STRING_CHARS (mode);
293
294 switch (*md)
295 {
296 case 'r':
297 flags |= O_RDONLY;
298 break;
299 case 'w':
300 flags |= O_WRONLY | O_CREAT | O_TRUNC;
301 break;
302 case 'a':
303 flags |= O_WRONLY | O_CREAT | O_APPEND;
304 break;
305 default:
306 scm_out_of_range (FUNC_NAME, mode);
307 }
308 ptr = md + 1;
309 while (*ptr != '\0')
310 {
311 switch (*ptr)
312 {
313 case '+':
314 flags = (flags & ~(O_RDONLY | O_WRONLY)) | O_RDWR;
315 break;
316 case 'b':
317 #if defined (O_BINARY)
318 flags |= O_BINARY;
319 #endif
320 break;
321 case '0': /* unbuffered: handled later. */
322 case 'l': /* line buffered: handled during output. */
323 break;
324 default:
325 scm_out_of_range (FUNC_NAME, mode);
326 }
327 ptr++;
328 }
329 SCM_SYSCALL (fdes = open (file, flags, 0666));
330 if (fdes == -1)
331 {
332 int en = errno;
333
334 SCM_SYSERROR_MSG ("~A: ~S",
335 scm_cons (scm_makfrom0str (strerror (en)),
336 scm_cons (filename, SCM_EOL)), en);
337 }
338 port = scm_fdes_to_port (fdes, md, filename);
339 return port;
340 }
341 #undef FUNC_NAME
342
343 \f
344 #ifdef __MINGW32__
345 /*
346 * Try getting the appropiate file flags for a given file descriptor
347 * under Windows. This incorporates some fancy operations because Windows
348 * differentiates between file, pipe and socket descriptors.
349 */
350 #ifndef O_ACCMODE
351 # define O_ACCMODE 0x0003
352 #endif
353
354 static int getflags (int fdes)
355 {
356 int flags = 0;
357 struct stat buf;
358 int error, optlen = sizeof (int);
359
360 /* Is this a socket ? */
361 if (getsockopt (fdes, SOL_SOCKET, SO_ERROR, (void *) &error, &optlen) >= 0)
362 flags = O_RDWR;
363 /* Maybe a regular file ? */
364 else if (fstat (fdes, &buf) < 0)
365 flags = -1;
366 else
367 {
368 /* Or an anonymous pipe handle ? */
369 if (buf.st_mode & _S_IFIFO)
370 flags = PeekNamedPipe ((HANDLE) _get_osfhandle (fdes), NULL, 0,
371 NULL, NULL, NULL) ? O_RDONLY : O_WRONLY;
372 /* stdin ? */
373 else if (fdes == fileno (stdin) && isatty (fdes))
374 flags = O_RDONLY;
375 /* stdout / stderr ? */
376 else if ((fdes == fileno (stdout) || fdes == fileno (stderr)) &&
377 isatty (fdes))
378 flags = O_WRONLY;
379 else
380 flags = buf.st_mode;
381 }
382 return flags;
383 }
384 #endif /* __MINGW32__ */
385
386 /* Building Guile ports from a file descriptor. */
387
388 /* Build a Scheme port from an open file descriptor `fdes'.
389 MODE indicates whether FILE is open for reading or writing; it uses
390 the same notation as open-file's second argument.
391 NAME is a string to be used as the port's filename.
392 */
393 SCM
394 scm_fdes_to_port (int fdes, char *mode, SCM name)
395 #define FUNC_NAME "scm_fdes_to_port"
396 {
397 long mode_bits = scm_mode_bits (mode);
398 SCM port;
399 scm_t_port *pt;
400 int flags;
401
402 /* test that fdes is valid. */
403 #ifdef __MINGW32__
404 flags = getflags (fdes);
405 #else
406 flags = fcntl (fdes, F_GETFL, 0);
407 #endif
408 if (flags == -1)
409 SCM_SYSERROR;
410 flags &= O_ACCMODE;
411 if (flags != O_RDWR
412 && ((flags != O_WRONLY && (mode_bits & SCM_WRTNG))
413 || (flags != O_RDONLY && (mode_bits & SCM_RDNG))))
414 {
415 SCM_MISC_ERROR ("requested file mode not available on fdes", SCM_EOL);
416 }
417
418 SCM_DEFER_INTS;
419
420 port = scm_new_port_table_entry (scm_tc16_fport);
421 SCM_SET_CELL_TYPE(port, scm_tc16_fport | mode_bits);
422 pt = SCM_PTAB_ENTRY(port);
423 {
424 scm_t_fport *fp
425 = (scm_t_fport *) scm_gc_malloc (sizeof (scm_t_fport), "file port");
426
427 fp->fdes = fdes;
428 pt->rw_random = SCM_FDES_RANDOM_P (fdes);
429 SCM_SETSTREAM (port, fp);
430 if (mode_bits & SCM_BUF0)
431 scm_fport_buffer_add (port, 0, 0);
432 else
433 scm_fport_buffer_add (port, -1, -1);
434 }
435 SCM_SET_FILENAME (port, name);
436 SCM_ALLOW_INTS;
437 return port;
438 }
439 #undef FUNC_NAME
440
441 /* Return a lower bound on the number of bytes available for input. */
442 static int
443 fport_input_waiting (SCM port)
444 {
445 int fdes = SCM_FSTREAM (port)->fdes;
446
447 #ifdef HAVE_SELECT
448 struct timeval timeout;
449 SELECT_TYPE read_set;
450 SELECT_TYPE write_set;
451 SELECT_TYPE except_set;
452
453 FD_ZERO (&read_set);
454 FD_ZERO (&write_set);
455 FD_ZERO (&except_set);
456
457 FD_SET (fdes, &read_set);
458
459 timeout.tv_sec = 0;
460 timeout.tv_usec = 0;
461
462 if (select (SELECT_SET_SIZE,
463 &read_set, &write_set, &except_set, &timeout)
464 < 0)
465 scm_syserror ("fport_input_waiting");
466 return FD_ISSET (fdes, &read_set) ? 1 : 0;
467 #elif defined (FIONREAD)
468 int remir;
469 ioctl(fdes, FIONREAD, &remir);
470 return remir;
471 #else
472 scm_misc_error ("fport_input_waiting",
473 "Not fully implemented on this platform",
474 SCM_EOL);
475 #endif
476 }
477
478 \f
479 static int
480 fport_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED)
481 {
482 scm_puts ("#<", port);
483 scm_print_port_mode (exp, port);
484 if (SCM_OPFPORTP (exp))
485 {
486 int fdes;
487 SCM name = SCM_FILENAME (exp);
488 if (SCM_STRINGP (name) || SCM_SYMBOLP (name))
489 scm_display (name, port);
490 else
491 scm_puts (SCM_PTOBNAME (SCM_PTOBNUM (exp)), port);
492 scm_putc (' ', port);
493 fdes = (SCM_FSTREAM (exp))->fdes;
494
495 #ifdef HAVE_TTYNAME
496 if (isatty (fdes))
497 scm_puts (ttyname (fdes), port);
498 else
499 #endif /* HAVE_TTYNAME */
500 scm_intprint (fdes, 10, port);
501 }
502 else
503 {
504 scm_puts (SCM_PTOBNAME (SCM_PTOBNUM (exp)), port);
505 scm_putc (' ', port);
506 scm_intprint ((scm_t_bits) SCM_PTAB_ENTRY (exp), 16, port);
507 }
508 scm_putc ('>', port);
509 return 1;
510 }
511
512 /* thread-local block for input on fport's fdes. */
513 static void
514 fport_wait_for_input (SCM port)
515 {
516 int fdes = SCM_FSTREAM (port)->fdes;
517
518 if (!fport_input_waiting (port))
519 {
520 int n;
521 SELECT_TYPE readfds;
522 int flags = fcntl (fdes, F_GETFL);
523
524 if (flags == -1)
525 scm_syserror ("scm_fdes_wait_for_input");
526 if (!(flags & O_NONBLOCK))
527 do
528 {
529 FD_ZERO (&readfds);
530 FD_SET (fdes, &readfds);
531 n = scm_internal_select (fdes + 1, &readfds, NULL, NULL, NULL);
532 }
533 while (n == -1 && errno == EINTR);
534 }
535 }
536
537 static void fport_flush (SCM port);
538
539 /* fill a port's read-buffer with a single read. returns the first
540 char or EOF if end of file. */
541 static int
542 fport_fill_input (SCM port)
543 {
544 long count;
545 scm_t_port *pt = SCM_PTAB_ENTRY (port);
546 scm_t_fport *fp = SCM_FSTREAM (port);
547
548 fport_wait_for_input (port);
549 SCM_SYSCALL (count = read (fp->fdes, pt->read_buf, pt->read_buf_size));
550 if (count == -1)
551 scm_syserror ("fport_fill_input");
552 if (count == 0)
553 return EOF;
554 else
555 {
556 pt->read_pos = pt->read_buf;
557 pt->read_end = pt->read_buf + count;
558 return *pt->read_buf;
559 }
560 }
561
562 static off_t
563 fport_seek (SCM port, off_t offset, int whence)
564 {
565 scm_t_port *pt = SCM_PTAB_ENTRY (port);
566 scm_t_fport *fp = SCM_FSTREAM (port);
567 off_t rv;
568 off_t result;
569
570 if (pt->rw_active == SCM_PORT_WRITE)
571 {
572 if (offset != 0 || whence != SEEK_CUR)
573 {
574 fport_flush (port);
575 result = rv = lseek (fp->fdes, offset, whence);
576 }
577 else
578 {
579 /* read current position without disturbing the buffer. */
580 rv = lseek (fp->fdes, offset, whence);
581 result = rv + (pt->write_pos - pt->write_buf);
582 }
583 }
584 else if (pt->rw_active == SCM_PORT_READ)
585 {
586 if (offset != 0 || whence != SEEK_CUR)
587 {
588 /* could expand to avoid a second seek. */
589 scm_end_input (port);
590 result = rv = lseek (fp->fdes, offset, whence);
591 }
592 else
593 {
594 /* read current position without disturbing the buffer
595 (particularly the unread-char buffer). */
596 rv = lseek (fp->fdes, offset, whence);
597 result = rv - (pt->read_end - pt->read_pos);
598
599 if (pt->read_buf == pt->putback_buf)
600 result -= pt->saved_read_end - pt->saved_read_pos;
601 }
602 }
603 else /* SCM_PORT_NEITHER */
604 {
605 result = rv = lseek (fp->fdes, offset, whence);
606 }
607
608 if (rv == -1)
609 scm_syserror ("fport_seek");
610
611 return result;
612 }
613
614 static void
615 fport_truncate (SCM port, off_t length)
616 {
617 scm_t_fport *fp = SCM_FSTREAM (port);
618
619 if (ftruncate (fp->fdes, length) == -1)
620 scm_syserror ("ftruncate");
621 }
622
623 /* helper for fport_write: try to write data, using multiple system
624 calls if required. */
625 #define FUNC_NAME "write_all"
626 static void write_all (SCM port, const void *data, size_t remaining)
627 {
628 int fdes = SCM_FSTREAM (port)->fdes;
629
630 while (remaining > 0)
631 {
632 size_t done;
633
634 SCM_SYSCALL (done = write (fdes, data, remaining));
635
636 if (done == -1)
637 SCM_SYSERROR;
638 remaining -= done;
639 data = ((const char *) data) + done;
640 }
641 }
642 #undef FUNC_NAME
643
644 static void
645 fport_write (SCM port, const void *data, size_t size)
646 {
647 /* this procedure tries to minimize the number of writes/flushes. */
648 scm_t_port *pt = SCM_PTAB_ENTRY (port);
649
650 if (pt->write_buf == &pt->shortbuf
651 || (pt->write_pos == pt->write_buf && size >= pt->write_buf_size))
652 {
653 /* "unbuffered" port, or
654 port with empty buffer and data won't fit in buffer. */
655 write_all (port, data, size);
656 return;
657 }
658
659 {
660 off_t space = pt->write_end - pt->write_pos;
661
662 if (size <= space)
663 {
664 /* data fits in buffer. */
665 memcpy (pt->write_pos, data, size);
666 pt->write_pos += size;
667 if (pt->write_pos == pt->write_end)
668 {
669 fport_flush (port);
670 /* we can skip the line-buffering check if nothing's buffered. */
671 return;
672 }
673 }
674 else
675 {
676 memcpy (pt->write_pos, data, space);
677 pt->write_pos = pt->write_end;
678 fport_flush (port);
679 {
680 const void *ptr = ((const char *) data) + space;
681 size_t remaining = size - space;
682
683 if (size >= pt->write_buf_size)
684 {
685 write_all (port, ptr, remaining);
686 return;
687 }
688 else
689 {
690 memcpy (pt->write_pos, ptr, remaining);
691 pt->write_pos += remaining;
692 }
693 }
694 }
695
696 /* handle line buffering. */
697 if ((SCM_CELL_WORD_0 (port) & SCM_BUFLINE) && memchr (data, '\n', size))
698 fport_flush (port);
699 }
700 }
701
702 /* becomes 1 when process is exiting: normal exception handling won't
703 work by this time. */
704 extern int scm_i_terminating;
705
706 static void
707 fport_flush (SCM port)
708 {
709 scm_t_port *pt = SCM_PTAB_ENTRY (port);
710 scm_t_fport *fp = SCM_FSTREAM (port);
711 unsigned char *ptr = pt->write_buf;
712 long init_size = pt->write_pos - pt->write_buf;
713 long remaining = init_size;
714
715 while (remaining > 0)
716 {
717 long count;
718
719 SCM_SYSCALL (count = write (fp->fdes, ptr, remaining));
720 if (count < 0)
721 {
722 /* error. assume nothing was written this call, but
723 fix up the buffer for any previous successful writes. */
724 long done = init_size - remaining;
725
726 if (done > 0)
727 {
728 int i;
729
730 for (i = 0; i < remaining; i++)
731 {
732 *(pt->write_buf + i) = *(pt->write_buf + done + i);
733 }
734 pt->write_pos = pt->write_buf + remaining;
735 }
736 if (scm_i_terminating)
737 {
738 const char *msg = "Error: could not flush file-descriptor ";
739 char buf[11];
740
741 write (2, msg, strlen (msg));
742 sprintf (buf, "%d\n", fp->fdes);
743 write (2, buf, strlen (buf));
744
745 count = remaining;
746 }
747 else if (scm_gc_running_p)
748 {
749 /* silently ignore the error. scm_error would abort if we
750 called it now. */
751 count = remaining;
752 }
753 else
754 scm_syserror ("fport_flush");
755 }
756 ptr += count;
757 remaining -= count;
758 }
759 pt->write_pos = pt->write_buf;
760 pt->rw_active = SCM_PORT_NEITHER;
761 }
762
763 /* clear the read buffer and adjust the file position for unread bytes. */
764 static void
765 fport_end_input (SCM port, int offset)
766 {
767 scm_t_fport *fp = SCM_FSTREAM (port);
768 scm_t_port *pt = SCM_PTAB_ENTRY (port);
769
770 offset += pt->read_end - pt->read_pos;
771
772 if (offset > 0)
773 {
774 pt->read_pos = pt->read_end;
775 /* will throw error if unread-char used at beginning of file
776 then attempting to write. seems correct. */
777 if (lseek (fp->fdes, -offset, SEEK_CUR) == -1)
778 scm_syserror ("fport_end_input");
779 }
780 pt->rw_active = SCM_PORT_NEITHER;
781 }
782
783 static int
784 fport_close (SCM port)
785 {
786 scm_t_fport *fp = SCM_FSTREAM (port);
787 scm_t_port *pt = SCM_PTAB_ENTRY (port);
788 int rv;
789
790 fport_flush (port);
791 SCM_SYSCALL (rv = close (fp->fdes));
792 if (rv == -1 && errno != EBADF)
793 {
794 if (scm_gc_running_p)
795 /* silently ignore the error. scm_error would abort if we
796 called it now. */
797 ;
798 else
799 scm_syserror ("fport_close");
800 }
801 if (pt->read_buf == pt->putback_buf)
802 pt->read_buf = pt->saved_read_buf;
803 if (pt->read_buf != &pt->shortbuf)
804 scm_gc_free (pt->read_buf, pt->read_buf_size, "port buffer");
805 if (pt->write_buf != &pt->shortbuf)
806 scm_gc_free (pt->write_buf, pt->write_buf_size, "port buffer");
807 scm_gc_free (fp, sizeof (*fp), "file port");
808 return rv;
809 }
810
811 static size_t
812 fport_free (SCM port)
813 {
814 fport_close (port);
815 return 0;
816 }
817
818 static scm_t_bits
819 scm_make_fptob ()
820 {
821 scm_t_bits tc = scm_make_port_type ("file", fport_fill_input, fport_write);
822
823 scm_set_port_free (tc, fport_free);
824 scm_set_port_print (tc, fport_print);
825 scm_set_port_flush (tc, fport_flush);
826 scm_set_port_end_input (tc, fport_end_input);
827 scm_set_port_close (tc, fport_close);
828 scm_set_port_seek (tc, fport_seek);
829 scm_set_port_truncate (tc, fport_truncate);
830 scm_set_port_input_waiting (tc, fport_input_waiting);
831
832 return tc;
833 }
834
835 void
836 scm_init_fports ()
837 {
838 scm_tc16_fport = scm_make_fptob ();
839
840 scm_c_define ("_IOFBF", SCM_MAKINUM (_IOFBF));
841 scm_c_define ("_IOLBF", SCM_MAKINUM (_IOLBF));
842 scm_c_define ("_IONBF", SCM_MAKINUM (_IONBF));
843
844 #include "libguile/fports.x"
845 }
846
847 /*
848 Local Variables:
849 c-file-style: "gnu"
850 End:
851 */