merge from 1.8 branch
[bpt/guile.git] / libguile / fports.c
1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003, 2004, 2006 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 #include "libguile/posix.h"
31 #include "libguile/dynwind.h"
32
33 #include "libguile/fports.h"
34
35 #ifdef HAVE_STRING_H
36 #include <string.h>
37 #endif
38 #ifdef HAVE_UNISTD_H
39 #include <unistd.h>
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 cmode = scm_to_int (mode);
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_t_bits)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 csize = scm_to_int (size);
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 scm_i_scm_pthread_mutex_lock (&scm_i_port_table_mutex);
203
204 for (i = 0; i < scm_i_port_table_size; i++)
205 {
206 SCM port = scm_i_port_table[i]->port;
207
208 if (SCM_FPORTP (port))
209 {
210 scm_t_fport *fp = SCM_FSTREAM (port);
211
212 if (fp->fdes == fd)
213 {
214 fp->fdes = dup (fd);
215 if (fp->fdes == -1)
216 scm_syserror ("scm_evict_ports");
217 scm_set_port_revealed_x (port, scm_from_int (0));
218 }
219 }
220 }
221
222 scm_i_pthread_mutex_unlock (&scm_i_port_table_mutex);
223 }
224
225
226 SCM_DEFINE (scm_file_port_p, "file-port?", 1, 0, 0,
227 (SCM obj),
228 "Determine whether @var{obj} is a port that is related to a file.")
229 #define FUNC_NAME s_scm_file_port_p
230 {
231 return scm_from_bool (SCM_FPORTP (obj));
232 }
233 #undef FUNC_NAME
234
235
236 /* scm_open_file
237 * Return a new port open on a given file.
238 *
239 * The mode string must match the pattern: [rwa+]** which
240 * is interpreted in the usual unix way.
241 *
242 * Return the new port.
243 */
244 SCM_DEFINE (scm_open_file, "open-file", 2, 0, 0,
245 (SCM filename, SCM mode),
246 "Open the file whose name is @var{filename}, and return a port\n"
247 "representing that file. The attributes of the port are\n"
248 "determined by the @var{mode} string. The way in which this is\n"
249 "interpreted is similar to C stdio. The first character must be\n"
250 "one of the following:\n"
251 "@table @samp\n"
252 "@item r\n"
253 "Open an existing file for input.\n"
254 "@item w\n"
255 "Open a file for output, creating it if it doesn't already exist\n"
256 "or removing its contents if it does.\n"
257 "@item a\n"
258 "Open a file for output, creating it if it doesn't already\n"
259 "exist. All writes to the port will go to the end of the file.\n"
260 "The \"append mode\" can be turned off while the port is in use\n"
261 "@pxref{Ports and File Descriptors, fcntl}\n"
262 "@end table\n"
263 "The following additional characters can be appended:\n"
264 "@table @samp\n"
265 "@item b\n"
266 "Open the underlying file in binary mode, if supported by the operating system. "
267 "@item +\n"
268 "Open the port for both input and output. E.g., @code{r+}: open\n"
269 "an existing file for both input and output.\n"
270 "@item 0\n"
271 "Create an \"unbuffered\" port. In this case input and output\n"
272 "operations are passed directly to the underlying port\n"
273 "implementation without additional buffering. This is likely to\n"
274 "slow down I/O operations. The buffering mode can be changed\n"
275 "while a port is in use @pxref{Ports and File Descriptors,\n"
276 "setvbuf}\n"
277 "@item l\n"
278 "Add line-buffering to the port. The port output buffer will be\n"
279 "automatically flushed whenever a newline character is written.\n"
280 "@end table\n"
281 "In theory we could create read/write ports which were buffered\n"
282 "in one direction only. However this isn't included in the\n"
283 "current interfaces. If a file cannot be opened with the access\n"
284 "requested, @code{open-file} throws an exception.")
285 #define FUNC_NAME s_scm_open_file
286 {
287 SCM port;
288 int fdes;
289 int flags = 0;
290 char *file;
291 char *md;
292 char *ptr;
293
294 scm_dynwind_begin (0);
295
296 file = scm_to_locale_string (filename);
297 scm_dynwind_free (file);
298
299 md = scm_to_locale_string (mode);
300 scm_dynwind_free (md);
301
302 switch (*md)
303 {
304 case 'r':
305 flags |= O_RDONLY;
306 break;
307 case 'w':
308 flags |= O_WRONLY | O_CREAT | O_TRUNC;
309 break;
310 case 'a':
311 flags |= O_WRONLY | O_CREAT | O_APPEND;
312 break;
313 default:
314 scm_out_of_range (FUNC_NAME, mode);
315 }
316 ptr = md + 1;
317 while (*ptr != '\0')
318 {
319 switch (*ptr)
320 {
321 case '+':
322 flags = (flags & ~(O_RDONLY | O_WRONLY)) | O_RDWR;
323 break;
324 case 'b':
325 #if defined (O_BINARY)
326 flags |= O_BINARY;
327 #endif
328 break;
329 case '0': /* unbuffered: handled later. */
330 case 'l': /* line buffered: handled during output. */
331 break;
332 default:
333 scm_out_of_range (FUNC_NAME, mode);
334 }
335 ptr++;
336 }
337 SCM_SYSCALL (fdes = open (file, flags, 0666));
338 if (fdes == -1)
339 {
340 int en = errno;
341
342 SCM_SYSERROR_MSG ("~A: ~S",
343 scm_cons (scm_strerror (scm_from_int (en)),
344 scm_cons (filename, SCM_EOL)), en);
345 }
346 port = scm_i_fdes_to_port (fdes, scm_i_mode_bits (mode), filename);
347
348 scm_dynwind_end ();
349
350 return port;
351 }
352 #undef FUNC_NAME
353
354 \f
355 #ifdef __MINGW32__
356 /*
357 * Try getting the appropiate file flags for a given file descriptor
358 * under Windows. This incorporates some fancy operations because Windows
359 * differentiates between file, pipe and socket descriptors.
360 */
361 #ifndef O_ACCMODE
362 # define O_ACCMODE 0x0003
363 #endif
364
365 static int getflags (int fdes)
366 {
367 int flags = 0;
368 struct stat buf;
369 int error, optlen = sizeof (int);
370
371 /* Is this a socket ? */
372 if (getsockopt (fdes, SOL_SOCKET, SO_ERROR, (void *) &error, &optlen) >= 0)
373 flags = O_RDWR;
374 /* Maybe a regular file ? */
375 else if (fstat (fdes, &buf) < 0)
376 flags = -1;
377 else
378 {
379 /* Or an anonymous pipe handle ? */
380 if (buf.st_mode & _S_IFIFO)
381 flags = PeekNamedPipe ((HANDLE) _get_osfhandle (fdes), NULL, 0,
382 NULL, NULL, NULL) ? O_RDONLY : O_WRONLY;
383 /* stdin ? */
384 else if (fdes == fileno (stdin) && isatty (fdes))
385 flags = O_RDONLY;
386 /* stdout / stderr ? */
387 else if ((fdes == fileno (stdout) || fdes == fileno (stderr)) &&
388 isatty (fdes))
389 flags = O_WRONLY;
390 else
391 flags = buf.st_mode;
392 }
393 return flags;
394 }
395 #endif /* __MINGW32__ */
396
397 /* Building Guile ports from a file descriptor. */
398
399 /* Build a Scheme port from an open file descriptor `fdes'.
400 MODE indicates whether FILE is open for reading or writing; it uses
401 the same notation as open-file's second argument.
402 NAME is a string to be used as the port's filename.
403 */
404 SCM
405 scm_i_fdes_to_port (int fdes, long mode_bits, SCM name)
406 #define FUNC_NAME "scm_fdes_to_port"
407 {
408 SCM port;
409 scm_t_port *pt;
410 int flags;
411
412 /* test that fdes is valid. */
413 #ifdef __MINGW32__
414 flags = getflags (fdes);
415 #else
416 flags = fcntl (fdes, F_GETFL, 0);
417 #endif
418 if (flags == -1)
419 SCM_SYSERROR;
420 flags &= O_ACCMODE;
421 if (flags != O_RDWR
422 && ((flags != O_WRONLY && (mode_bits & SCM_WRTNG))
423 || (flags != O_RDONLY && (mode_bits & SCM_RDNG))))
424 {
425 SCM_MISC_ERROR ("requested file mode not available on fdes", SCM_EOL);
426 }
427
428 scm_i_scm_pthread_mutex_lock (&scm_i_port_table_mutex);
429
430 port = scm_new_port_table_entry (scm_tc16_fport);
431 SCM_SET_CELL_TYPE(port, scm_tc16_fport | mode_bits);
432 pt = SCM_PTAB_ENTRY(port);
433 {
434 scm_t_fport *fp
435 = (scm_t_fport *) scm_gc_malloc (sizeof (scm_t_fport), "file port");
436
437 fp->fdes = fdes;
438 pt->rw_random = SCM_FDES_RANDOM_P (fdes);
439 SCM_SETSTREAM (port, fp);
440 if (mode_bits & SCM_BUF0)
441 scm_fport_buffer_add (port, 0, 0);
442 else
443 scm_fport_buffer_add (port, -1, -1);
444 }
445 SCM_SET_FILENAME (port, name);
446 scm_i_pthread_mutex_unlock (&scm_i_port_table_mutex);
447 return port;
448 }
449 #undef FUNC_NAME
450
451 SCM
452 scm_fdes_to_port (int fdes, char *mode, SCM name)
453 {
454 return scm_i_fdes_to_port (fdes, scm_mode_bits (mode), name);
455 }
456
457 /* Return a lower bound on the number of bytes available for input. */
458 static int
459 fport_input_waiting (SCM port)
460 {
461 #ifdef HAVE_SELECT
462 int fdes = SCM_FSTREAM (port)->fdes;
463 struct timeval timeout;
464 SELECT_TYPE read_set;
465 SELECT_TYPE write_set;
466 SELECT_TYPE except_set;
467
468 FD_ZERO (&read_set);
469 FD_ZERO (&write_set);
470 FD_ZERO (&except_set);
471
472 FD_SET (fdes, &read_set);
473
474 timeout.tv_sec = 0;
475 timeout.tv_usec = 0;
476
477 if (select (SELECT_SET_SIZE,
478 &read_set, &write_set, &except_set, &timeout)
479 < 0)
480 scm_syserror ("fport_input_waiting");
481 return FD_ISSET (fdes, &read_set) ? 1 : 0;
482
483 #elif HAVE_IOCTL && defined (FIONREAD)
484 /* Note: cannot test just defined(FIONREAD) here, since mingw has FIONREAD
485 (for use with winsock ioctlsocket()) but not ioctl(). */
486 int fdes = SCM_FSTREAM (port)->fdes;
487 int remir;
488 ioctl(fdes, FIONREAD, &remir);
489 return remir;
490
491 #else
492 scm_misc_error ("fport_input_waiting",
493 "Not fully implemented on this platform",
494 SCM_EOL);
495 #endif
496 }
497
498 \f
499 static int
500 fport_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED)
501 {
502 scm_puts ("#<", port);
503 scm_print_port_mode (exp, port);
504 if (SCM_OPFPORTP (exp))
505 {
506 int fdes;
507 SCM name = SCM_FILENAME (exp);
508 if (scm_is_string (name) || scm_is_symbol (name))
509 scm_display (name, port);
510 else
511 scm_puts (SCM_PTOBNAME (SCM_PTOBNUM (exp)), port);
512 scm_putc (' ', port);
513 fdes = (SCM_FSTREAM (exp))->fdes;
514
515 #ifdef HAVE_TTYNAME
516 if (isatty (fdes))
517 scm_display (scm_ttyname (exp), port);
518 else
519 #endif /* HAVE_TTYNAME */
520 scm_intprint (fdes, 10, port);
521 }
522 else
523 {
524 scm_puts (SCM_PTOBNAME (SCM_PTOBNUM (exp)), port);
525 scm_putc (' ', port);
526 scm_uintprint ((scm_t_bits) SCM_PTAB_ENTRY (exp), 16, port);
527 }
528 scm_putc ('>', port);
529 return 1;
530 }
531
532 #ifndef __MINGW32__
533 /* thread-local block for input on fport's fdes. */
534 static void
535 fport_wait_for_input (SCM port)
536 {
537 int fdes = SCM_FSTREAM (port)->fdes;
538
539 if (!fport_input_waiting (port))
540 {
541 int n;
542 SELECT_TYPE readfds;
543 int flags = fcntl (fdes, F_GETFL);
544
545 if (flags == -1)
546 scm_syserror ("scm_fdes_wait_for_input");
547 if (!(flags & O_NONBLOCK))
548 do
549 {
550 FD_ZERO (&readfds);
551 FD_SET (fdes, &readfds);
552 n = scm_std_select (fdes + 1, &readfds, NULL, NULL, NULL);
553 }
554 while (n == -1 && errno == EINTR);
555 }
556 }
557 #endif /* !__MINGW32__ */
558
559 static void fport_flush (SCM port);
560
561 /* fill a port's read-buffer with a single read. returns the first
562 char or EOF if end of file. */
563 static int
564 fport_fill_input (SCM port)
565 {
566 long count;
567 scm_t_port *pt = SCM_PTAB_ENTRY (port);
568 scm_t_fport *fp = SCM_FSTREAM (port);
569
570 #ifndef __MINGW32__
571 fport_wait_for_input (port);
572 #endif /* !__MINGW32__ */
573 SCM_SYSCALL (count = read (fp->fdes, pt->read_buf, pt->read_buf_size));
574 if (count == -1)
575 scm_syserror ("fport_fill_input");
576 if (count == 0)
577 return EOF;
578 else
579 {
580 pt->read_pos = pt->read_buf;
581 pt->read_end = pt->read_buf + count;
582 return *pt->read_buf;
583 }
584 }
585
586 static off_t
587 fport_seek (SCM port, off_t offset, int whence)
588 {
589 scm_t_port *pt = SCM_PTAB_ENTRY (port);
590 scm_t_fport *fp = SCM_FSTREAM (port);
591 off_t rv;
592 off_t result;
593
594 if (pt->rw_active == SCM_PORT_WRITE)
595 {
596 if (offset != 0 || whence != SEEK_CUR)
597 {
598 fport_flush (port);
599 result = rv = lseek (fp->fdes, offset, whence);
600 }
601 else
602 {
603 /* read current position without disturbing the buffer. */
604 rv = lseek (fp->fdes, offset, whence);
605 result = rv + (pt->write_pos - pt->write_buf);
606 }
607 }
608 else if (pt->rw_active == SCM_PORT_READ)
609 {
610 if (offset != 0 || whence != SEEK_CUR)
611 {
612 /* could expand to avoid a second seek. */
613 scm_end_input (port);
614 result = rv = lseek (fp->fdes, offset, whence);
615 }
616 else
617 {
618 /* read current position without disturbing the buffer
619 (particularly the unread-char buffer). */
620 rv = lseek (fp->fdes, offset, whence);
621 result = rv - (pt->read_end - pt->read_pos);
622
623 if (pt->read_buf == pt->putback_buf)
624 result -= pt->saved_read_end - pt->saved_read_pos;
625 }
626 }
627 else /* SCM_PORT_NEITHER */
628 {
629 result = rv = lseek (fp->fdes, offset, whence);
630 }
631
632 if (rv == -1)
633 scm_syserror ("fport_seek");
634
635 return result;
636 }
637
638 static void
639 fport_truncate (SCM port, off_t length)
640 {
641 scm_t_fport *fp = SCM_FSTREAM (port);
642
643 if (ftruncate (fp->fdes, length) == -1)
644 scm_syserror ("ftruncate");
645 }
646
647 /* helper for fport_write: try to write data, using multiple system
648 calls if required. */
649 #define FUNC_NAME "write_all"
650 static void write_all (SCM port, const void *data, size_t remaining)
651 {
652 int fdes = SCM_FSTREAM (port)->fdes;
653
654 while (remaining > 0)
655 {
656 size_t done;
657
658 SCM_SYSCALL (done = write (fdes, data, remaining));
659
660 if (done == -1)
661 SCM_SYSERROR;
662 remaining -= done;
663 data = ((const char *) data) + done;
664 }
665 }
666 #undef FUNC_NAME
667
668 static void
669 fport_write (SCM port, const void *data, size_t size)
670 {
671 /* this procedure tries to minimize the number of writes/flushes. */
672 scm_t_port *pt = SCM_PTAB_ENTRY (port);
673
674 if (pt->write_buf == &pt->shortbuf
675 || (pt->write_pos == pt->write_buf && size >= pt->write_buf_size))
676 {
677 /* "unbuffered" port, or
678 port with empty buffer and data won't fit in buffer. */
679 write_all (port, data, size);
680 return;
681 }
682
683 {
684 off_t space = pt->write_end - pt->write_pos;
685
686 if (size <= space)
687 {
688 /* data fits in buffer. */
689 memcpy (pt->write_pos, data, size);
690 pt->write_pos += size;
691 if (pt->write_pos == pt->write_end)
692 {
693 fport_flush (port);
694 /* we can skip the line-buffering check if nothing's buffered. */
695 return;
696 }
697 }
698 else
699 {
700 memcpy (pt->write_pos, data, space);
701 pt->write_pos = pt->write_end;
702 fport_flush (port);
703 {
704 const void *ptr = ((const char *) data) + space;
705 size_t remaining = size - space;
706
707 if (size >= pt->write_buf_size)
708 {
709 write_all (port, ptr, remaining);
710 return;
711 }
712 else
713 {
714 memcpy (pt->write_pos, ptr, remaining);
715 pt->write_pos += remaining;
716 }
717 }
718 }
719
720 /* handle line buffering. */
721 if ((SCM_CELL_WORD_0 (port) & SCM_BUFLINE) && memchr (data, '\n', size))
722 fport_flush (port);
723 }
724 }
725
726 /* becomes 1 when process is exiting: normal exception handling won't
727 work by this time. */
728 extern int scm_i_terminating;
729
730 static void
731 fport_flush (SCM port)
732 {
733 scm_t_port *pt = SCM_PTAB_ENTRY (port);
734 scm_t_fport *fp = SCM_FSTREAM (port);
735 unsigned char *ptr = pt->write_buf;
736 long init_size = pt->write_pos - pt->write_buf;
737 long remaining = init_size;
738
739 while (remaining > 0)
740 {
741 long count;
742
743 SCM_SYSCALL (count = write (fp->fdes, ptr, remaining));
744 if (count < 0)
745 {
746 /* error. assume nothing was written this call, but
747 fix up the buffer for any previous successful writes. */
748 long done = init_size - remaining;
749
750 if (done > 0)
751 {
752 int i;
753
754 for (i = 0; i < remaining; i++)
755 {
756 *(pt->write_buf + i) = *(pt->write_buf + done + i);
757 }
758 pt->write_pos = pt->write_buf + remaining;
759 }
760 if (scm_i_terminating)
761 {
762 const char *msg = "Error: could not flush file-descriptor ";
763 char buf[11];
764
765 write (2, msg, strlen (msg));
766 sprintf (buf, "%d\n", fp->fdes);
767 write (2, buf, strlen (buf));
768
769 count = remaining;
770 }
771 else if (scm_gc_running_p)
772 {
773 /* silently ignore the error. scm_error would abort if we
774 called it now. */
775 count = remaining;
776 }
777 else
778 scm_syserror ("fport_flush");
779 }
780 ptr += count;
781 remaining -= count;
782 }
783 pt->write_pos = pt->write_buf;
784 pt->rw_active = SCM_PORT_NEITHER;
785 }
786
787 /* clear the read buffer and adjust the file position for unread bytes. */
788 static void
789 fport_end_input (SCM port, int offset)
790 {
791 scm_t_fport *fp = SCM_FSTREAM (port);
792 scm_t_port *pt = SCM_PTAB_ENTRY (port);
793
794 offset += pt->read_end - pt->read_pos;
795
796 if (offset > 0)
797 {
798 pt->read_pos = pt->read_end;
799 /* will throw error if unread-char used at beginning of file
800 then attempting to write. seems correct. */
801 if (lseek (fp->fdes, -offset, SEEK_CUR) == -1)
802 scm_syserror ("fport_end_input");
803 }
804 pt->rw_active = SCM_PORT_NEITHER;
805 }
806
807 static int
808 fport_close (SCM port)
809 {
810 scm_t_fport *fp = SCM_FSTREAM (port);
811 scm_t_port *pt = SCM_PTAB_ENTRY (port);
812 int rv;
813
814 fport_flush (port);
815 SCM_SYSCALL (rv = close (fp->fdes));
816 if (rv == -1 && errno != EBADF)
817 {
818 if (scm_gc_running_p)
819 /* silently ignore the error. scm_error would abort if we
820 called it now. */
821 ;
822 else
823 scm_syserror ("fport_close");
824 }
825 if (pt->read_buf == pt->putback_buf)
826 pt->read_buf = pt->saved_read_buf;
827 if (pt->read_buf != &pt->shortbuf)
828 scm_gc_free (pt->read_buf, pt->read_buf_size, "port buffer");
829 if (pt->write_buf != &pt->shortbuf)
830 scm_gc_free (pt->write_buf, pt->write_buf_size, "port buffer");
831 scm_gc_free (fp, sizeof (*fp), "file port");
832 return rv;
833 }
834
835 static size_t
836 fport_free (SCM port)
837 {
838 fport_close (port);
839 return 0;
840 }
841
842 static scm_t_bits
843 scm_make_fptob ()
844 {
845 scm_t_bits tc = scm_make_port_type ("file", fport_fill_input, fport_write);
846
847 scm_set_port_free (tc, fport_free);
848 scm_set_port_print (tc, fport_print);
849 scm_set_port_flush (tc, fport_flush);
850 scm_set_port_end_input (tc, fport_end_input);
851 scm_set_port_close (tc, fport_close);
852 scm_set_port_seek (tc, fport_seek);
853 scm_set_port_truncate (tc, fport_truncate);
854 scm_set_port_input_waiting (tc, fport_input_waiting);
855
856 return tc;
857 }
858
859 void
860 scm_init_fports ()
861 {
862 scm_tc16_fport = scm_make_fptob ();
863
864 scm_c_define ("_IOFBF", scm_from_int (_IOFBF));
865 scm_c_define ("_IOLBF", scm_from_int (_IOLBF));
866 scm_c_define ("_IONBF", scm_from_int (_IONBF));
867
868 #include "libguile/fports.x"
869 }
870
871 /*
872 Local Variables:
873 c-file-style: "gnu"
874 End:
875 */