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748086b7 | 1 | /* Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 |
8f2a1406 | 2 | Free Software Foundation, Inc. |
6de9cd9a | 3 | Contributed by Andy Vaught |
10256cbe | 4 | F2003 I/O support contributed by Jerry DeLisle |
6de9cd9a DN |
5 | |
6 | This file is part of the GNU Fortran 95 runtime library (libgfortran). | |
7 | ||
8 | Libgfortran is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
748086b7 | 10 | the Free Software Foundation; either version 3, or (at your option) |
6de9cd9a DN |
11 | any later version. |
12 | ||
13 | Libgfortran is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
748086b7 JJ |
18 | Under Section 7 of GPL version 3, you are granted additional |
19 | permissions described in the GCC Runtime Library Exception, version | |
20 | 3.1, as published by the Free Software Foundation. | |
21 | ||
22 | You should have received a copy of the GNU General Public License and | |
23 | a copy of the GCC Runtime Library Exception along with this program; | |
24 | see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
25 | <http://www.gnu.org/licenses/>. */ | |
6de9cd9a DN |
26 | |
27 | /* Unix stream I/O module */ | |
28 | ||
36ae8a61 | 29 | #include "io.h" |
92cbdb68 | 30 | #include "unix.h" |
6de9cd9a DN |
31 | #include <stdlib.h> |
32 | #include <limits.h> | |
33 | ||
34 | #include <unistd.h> | |
35 | #include <sys/stat.h> | |
36 | #include <fcntl.h> | |
59154ed2 | 37 | #include <assert.h> |
6de9cd9a | 38 | |
6de9cd9a DN |
39 | #include <string.h> |
40 | #include <errno.h> | |
41 | ||
fe046210 FXC |
42 | |
43 | /* For mingw, we don't identify files by their inode number, but by a | |
44 | 64-bit identifier created from a BY_HANDLE_FILE_INFORMATION. */ | |
c9828e78 | 45 | #ifdef __MINGW32__ |
fe046210 FXC |
46 | |
47 | #define WIN32_LEAN_AND_MEAN | |
48 | #include <windows.h> | |
49 | ||
a4384bad | 50 | #define lseek _lseeki64 |
c9828e78 JB |
51 | #define fstat _fstati64 |
52 | #define stat _stati64 | |
53 | typedef struct _stati64 gfstat_t; | |
a4384bad | 54 | |
c9828e78 | 55 | #ifndef HAVE_WORKING_STAT |
fe046210 FXC |
56 | static uint64_t |
57 | id_from_handle (HANDLE hFile) | |
58 | { | |
59 | BY_HANDLE_FILE_INFORMATION FileInformation; | |
60 | ||
61 | if (hFile == INVALID_HANDLE_VALUE) | |
62 | return 0; | |
63 | ||
64 | memset (&FileInformation, 0, sizeof(FileInformation)); | |
65 | if (!GetFileInformationByHandle (hFile, &FileInformation)) | |
66 | return 0; | |
67 | ||
68 | return ((uint64_t) FileInformation.nFileIndexLow) | |
69 | | (((uint64_t) FileInformation.nFileIndexHigh) << 32); | |
70 | } | |
71 | ||
72 | ||
73 | static uint64_t | |
74 | id_from_path (const char *path) | |
75 | { | |
76 | HANDLE hFile; | |
77 | uint64_t res; | |
78 | ||
79 | if (!path || !*path || access (path, F_OK)) | |
80 | return (uint64_t) -1; | |
81 | ||
82 | hFile = CreateFile (path, 0, 0, NULL, OPEN_EXISTING, | |
83 | FILE_FLAG_BACKUP_SEMANTICS | FILE_ATTRIBUTE_READONLY, | |
84 | NULL); | |
85 | res = id_from_handle (hFile); | |
86 | CloseHandle (hFile); | |
87 | return res; | |
88 | } | |
89 | ||
90 | ||
91 | static uint64_t | |
92 | id_from_fd (const int fd) | |
93 | { | |
94 | return id_from_handle ((HANDLE) _get_osfhandle (fd)); | |
95 | } | |
96 | ||
97 | #endif | |
98 | ||
c9828e78 JB |
99 | #else |
100 | typedef struct stat gfstat_t; | |
101 | #endif | |
102 | ||
6de9cd9a DN |
103 | #ifndef PATH_MAX |
104 | #define PATH_MAX 1024 | |
105 | #endif | |
106 | ||
f596fc98 AL |
107 | #ifndef PROT_READ |
108 | #define PROT_READ 1 | |
109 | #endif | |
110 | ||
111 | #ifndef PROT_WRITE | |
112 | #define PROT_WRITE 2 | |
113 | #endif | |
114 | ||
41724e6a AL |
115 | /* These flags aren't defined on all targets (mingw32), so provide them |
116 | here. */ | |
117 | #ifndef S_IRGRP | |
118 | #define S_IRGRP 0 | |
119 | #endif | |
120 | ||
121 | #ifndef S_IWGRP | |
122 | #define S_IWGRP 0 | |
123 | #endif | |
124 | ||
125 | #ifndef S_IROTH | |
126 | #define S_IROTH 0 | |
127 | #endif | |
128 | ||
129 | #ifndef S_IWOTH | |
130 | #define S_IWOTH 0 | |
131 | #endif | |
132 | ||
0dce3ca1 | 133 | |
7812c78c | 134 | /* Unix and internal stream I/O module */ |
0dce3ca1 | 135 | |
7812c78c | 136 | static const int BUFFER_SIZE = 8192; |
0dce3ca1 FXC |
137 | |
138 | typedef struct | |
139 | { | |
140 | stream st; | |
141 | ||
0dce3ca1 FXC |
142 | gfc_offset buffer_offset; /* File offset of the start of the buffer */ |
143 | gfc_offset physical_offset; /* Current physical file offset */ | |
144 | gfc_offset logical_offset; /* Current logical file offset */ | |
0dce3ca1 FXC |
145 | gfc_offset file_length; /* Length of the file, -1 if not seekable. */ |
146 | ||
7812c78c JD |
147 | char *buffer; /* Pointer to the buffer. */ |
148 | int fd; /* The POSIX file descriptor. */ | |
149 | ||
0dce3ca1 FXC |
150 | int active; /* Length of valid bytes in the buffer */ |
151 | ||
152 | int prot; | |
7812c78c | 153 | int ndirty; /* Dirty bytes starting at buffer_offset */ |
0dce3ca1 FXC |
154 | |
155 | int special_file; /* =1 if the fd refers to a special file */ | |
0dce3ca1 FXC |
156 | } |
157 | unix_stream; | |
158 | ||
c132497f | 159 | |
6de9cd9a DN |
160 | /* fix_fd()-- Given a file descriptor, make sure it is not one of the |
161 | * standard descriptors, returning a non-standard descriptor. If the | |
162 | * user specifies that system errors should go to standard output, | |
163 | * then closes standard output, we don't want the system errors to a | |
164 | * file that has been given file descriptor 1 or 0. We want to send | |
165 | * the error to the invalid descriptor. */ | |
166 | ||
167 | static int | |
168 | fix_fd (int fd) | |
169 | { | |
2515e5a7 | 170 | #ifdef HAVE_DUP |
6de9cd9a DN |
171 | int input, output, error; |
172 | ||
173 | input = output = error = 0; | |
174 | ||
f21edfd6 RH |
175 | /* Unix allocates the lowest descriptors first, so a loop is not |
176 | required, but this order is. */ | |
6de9cd9a DN |
177 | if (fd == STDIN_FILENO) |
178 | { | |
179 | fd = dup (fd); | |
180 | input = 1; | |
181 | } | |
182 | if (fd == STDOUT_FILENO) | |
183 | { | |
184 | fd = dup (fd); | |
185 | output = 1; | |
186 | } | |
187 | if (fd == STDERR_FILENO) | |
188 | { | |
189 | fd = dup (fd); | |
190 | error = 1; | |
191 | } | |
192 | ||
193 | if (input) | |
194 | close (STDIN_FILENO); | |
195 | if (output) | |
196 | close (STDOUT_FILENO); | |
197 | if (error) | |
198 | close (STDERR_FILENO); | |
2515e5a7 | 199 | #endif |
6de9cd9a DN |
200 | |
201 | return fd; | |
202 | } | |
203 | ||
204 | ||
159840cb FXC |
205 | /* If the stream corresponds to a preconnected unit, we flush the |
206 | corresponding C stream. This is bugware for mixed C-Fortran codes | |
207 | where the C code doesn't flush I/O before returning. */ | |
208 | void | |
209 | flush_if_preconnected (stream * s) | |
210 | { | |
211 | int fd; | |
212 | ||
213 | fd = ((unix_stream *) s)->fd; | |
214 | if (fd == STDIN_FILENO) | |
215 | fflush (stdin); | |
216 | else if (fd == STDOUT_FILENO) | |
217 | fflush (stdout); | |
218 | else if (fd == STDERR_FILENO) | |
219 | fflush (stderr); | |
220 | } | |
221 | ||
6de9cd9a | 222 | |
7812c78c JD |
223 | /* get_oserror()-- Get the most recent operating system error. For |
224 | * unix, this is errno. */ | |
0dc43461 | 225 | |
7812c78c JD |
226 | const char * |
227 | get_oserror (void) | |
6de9cd9a | 228 | { |
7812c78c | 229 | return strerror (errno); |
0dc43461 | 230 | } |
6de9cd9a | 231 | |
6de9cd9a | 232 | |
7812c78c JD |
233 | /******************************************************************** |
234 | Raw I/O functions (read, write, seek, tell, truncate, close). | |
235 | ||
236 | These functions wrap the basic POSIX I/O syscalls. Any deviation in | |
237 | semantics is a bug, except the following: write restarts in case | |
238 | of being interrupted by a signal, and as the first argument the | |
239 | functions take the unix_stream struct rather than an integer file | |
240 | descriptor. Also, for POSIX read() and write() a nbyte argument larger | |
241 | than SSIZE_MAX is undefined; here the type of nbyte is ssize_t rather | |
242 | than size_t as for POSIX read/write. | |
243 | *********************************************************************/ | |
6de9cd9a | 244 | |
0dc43461 | 245 | static int |
7812c78c | 246 | raw_flush (unix_stream * s __attribute__ ((unused))) |
0dc43461 | 247 | { |
7812c78c | 248 | return 0; |
6de9cd9a DN |
249 | } |
250 | ||
7812c78c JD |
251 | static ssize_t |
252 | raw_read (unix_stream * s, void * buf, ssize_t nbyte) | |
253 | { | |
254 | /* For read we can't do I/O in a loop like raw_write does, because | |
255 | that will break applications that wait for interactive I/O. */ | |
256 | return read (s->fd, buf, nbyte); | |
257 | } | |
6de9cd9a | 258 | |
7812c78c JD |
259 | static ssize_t |
260 | raw_write (unix_stream * s, const void * buf, ssize_t nbyte) | |
6de9cd9a | 261 | { |
7812c78c | 262 | ssize_t trans, bytes_left; |
0dc43461 | 263 | char *buf_st; |
0dc43461 | 264 | |
7812c78c | 265 | bytes_left = nbyte; |
0dc43461 JB |
266 | buf_st = (char *) buf; |
267 | ||
268 | /* We must write in a loop since some systems don't restart system | |
269 | calls in case of a signal. */ | |
270 | while (bytes_left > 0) | |
6de9cd9a | 271 | { |
7812c78c | 272 | trans = write (s->fd, buf_st, bytes_left); |
0dc43461 JB |
273 | if (trans < 0) |
274 | { | |
275 | if (errno == EINTR) | |
276 | continue; | |
277 | else | |
7812c78c | 278 | return trans; |
0dc43461 JB |
279 | } |
280 | buf_st += trans; | |
281 | bytes_left -= trans; | |
6de9cd9a DN |
282 | } |
283 | ||
7812c78c | 284 | return nbyte - bytes_left; |
6de9cd9a | 285 | } |
6de9cd9a | 286 | |
a4384bad JB |
287 | static gfc_offset |
288 | raw_seek (unix_stream * s, gfc_offset offset, int whence) | |
7812c78c JD |
289 | { |
290 | return lseek (s->fd, offset, whence); | |
291 | } | |
6de9cd9a | 292 | |
a4384bad | 293 | static gfc_offset |
7812c78c JD |
294 | raw_tell (unix_stream * s) |
295 | { | |
296 | return lseek (s->fd, 0, SEEK_CUR); | |
297 | } | |
6de9cd9a | 298 | |
7812c78c | 299 | static int |
a4384bad | 300 | raw_truncate (unix_stream * s, gfc_offset length) |
6de9cd9a | 301 | { |
a4384bad JB |
302 | #ifdef __MINGW32__ |
303 | HANDLE h; | |
304 | gfc_offset cur; | |
305 | ||
306 | if (isatty (s->fd)) | |
307 | { | |
308 | errno = EBADF; | |
309 | return -1; | |
310 | } | |
311 | h = _get_osfhandle (s->fd); | |
312 | if (h == INVALID_HANDLE_VALUE) | |
313 | { | |
314 | errno = EBADF; | |
315 | return -1; | |
316 | } | |
317 | cur = lseek (s->fd, 0, SEEK_CUR); | |
318 | if (cur == -1) | |
319 | return -1; | |
320 | if (lseek (s->fd, length, SEEK_SET) == -1) | |
321 | goto error; | |
322 | if (!SetEndOfFile (h)) | |
323 | { | |
324 | errno = EBADF; | |
325 | goto error; | |
326 | } | |
327 | if (lseek (s->fd, cur, SEEK_SET) == -1) | |
328 | return -1; | |
329 | return 0; | |
330 | error: | |
331 | lseek (s->fd, cur, SEEK_SET); | |
332 | return -1; | |
333 | #elif defined HAVE_FTRUNCATE | |
7812c78c JD |
334 | return ftruncate (s->fd, length); |
335 | #elif defined HAVE_CHSIZE | |
336 | return chsize (s->fd, length); | |
337 | #else | |
338 | runtime_error ("required ftruncate or chsize support not present"); | |
339 | return -1; | |
340 | #endif | |
6de9cd9a DN |
341 | } |
342 | ||
7812c78c JD |
343 | static int |
344 | raw_close (unix_stream * s) | |
345 | { | |
346 | int retval; | |
347 | ||
4197c13d L |
348 | if (s->fd != STDOUT_FILENO |
349 | && s->fd != STDERR_FILENO | |
350 | && s->fd != STDIN_FILENO) | |
351 | retval = close (s->fd); | |
352 | else | |
2ac7316d | 353 | retval = 0; |
7812c78c JD |
354 | free_mem (s); |
355 | return retval; | |
356 | } | |
6de9cd9a | 357 | |
7812c78c JD |
358 | static int |
359 | raw_init (unix_stream * s) | |
360 | { | |
361 | s->st.read = (void *) raw_read; | |
362 | s->st.write = (void *) raw_write; | |
363 | s->st.seek = (void *) raw_seek; | |
364 | s->st.tell = (void *) raw_tell; | |
d26014d2 | 365 | s->st.trunc = (void *) raw_truncate; |
7812c78c JD |
366 | s->st.close = (void *) raw_close; |
367 | s->st.flush = (void *) raw_flush; | |
6de9cd9a | 368 | |
7812c78c JD |
369 | s->buffer = NULL; |
370 | return 0; | |
371 | } | |
0dc43461 | 372 | |
6de9cd9a | 373 | |
7812c78c JD |
374 | /********************************************************************* |
375 | Buffered I/O functions. These functions have the same semantics as the | |
376 | raw I/O functions above, except that they are buffered in order to | |
377 | improve performance. The buffer must be flushed when switching from | |
378 | reading to writing and vice versa. | |
379 | *********************************************************************/ | |
380 | ||
381 | static int | |
382 | buf_flush (unix_stream * s) | |
6de9cd9a | 383 | { |
7812c78c JD |
384 | int writelen; |
385 | ||
386 | /* Flushing in read mode means discarding read bytes. */ | |
387 | s->active = 0; | |
0dc43461 | 388 | |
6de9cd9a | 389 | if (s->ndirty == 0) |
7812c78c | 390 | return 0; |
779f3975 | 391 | |
7812c78c JD |
392 | if (s->file_length != -1 && s->physical_offset != s->buffer_offset |
393 | && lseek (s->fd, s->buffer_offset, SEEK_SET) < 0) | |
394 | return -1; | |
6de9cd9a | 395 | |
7812c78c | 396 | writelen = raw_write (s, s->buffer, s->ndirty); |
6de9cd9a | 397 | |
7812c78c | 398 | s->physical_offset = s->buffer_offset + writelen; |
bf1df0a0 | 399 | |
7812c78c | 400 | /* Don't increment file_length if the file is non-seekable. */ |
bf1df0a0 | 401 | if (s->file_length != -1 && s->physical_offset > s->file_length) |
7812c78c | 402 | s->file_length = s->physical_offset; |
0dc43461 JB |
403 | |
404 | s->ndirty -= writelen; | |
405 | if (s->ndirty != 0) | |
7812c78c | 406 | return -1; |
6de9cd9a | 407 | |
7812c78c | 408 | return 0; |
6de9cd9a DN |
409 | } |
410 | ||
7812c78c JD |
411 | static ssize_t |
412 | buf_read (unix_stream * s, void * buf, ssize_t nbyte) | |
6de9cd9a | 413 | { |
7812c78c JD |
414 | if (s->active == 0) |
415 | s->buffer_offset = s->logical_offset; | |
899583cb | 416 | |
7812c78c JD |
417 | /* Is the data we want in the buffer? */ |
418 | if (s->logical_offset + nbyte <= s->buffer_offset + s->active | |
419 | && s->buffer_offset <= s->logical_offset) | |
420 | memcpy (buf, s->buffer + (s->logical_offset - s->buffer_offset), nbyte); | |
899583cb JD |
421 | else |
422 | { | |
7812c78c JD |
423 | /* First copy the active bytes if applicable, then read the rest |
424 | either directly or filling the buffer. */ | |
425 | char *p; | |
426 | int nread = 0; | |
427 | ssize_t to_read, did_read; | |
428 | gfc_offset new_logical; | |
429 | ||
430 | p = (char *) buf; | |
431 | if (s->logical_offset >= s->buffer_offset | |
432 | && s->buffer_offset + s->active >= s->logical_offset) | |
433 | { | |
434 | nread = s->active - (s->logical_offset - s->buffer_offset); | |
435 | memcpy (buf, s->buffer + (s->logical_offset - s->buffer_offset), | |
436 | nread); | |
437 | p += nread; | |
438 | } | |
439 | /* At this point we consider all bytes in the buffer discarded. */ | |
440 | to_read = nbyte - nread; | |
441 | new_logical = s->logical_offset + nread; | |
442 | if (s->file_length != -1 && s->physical_offset != new_logical | |
443 | && lseek (s->fd, new_logical, SEEK_SET) < 0) | |
444 | return -1; | |
445 | s->buffer_offset = s->physical_offset = new_logical; | |
446 | if (to_read <= BUFFER_SIZE/2) | |
447 | { | |
448 | did_read = raw_read (s, s->buffer, BUFFER_SIZE); | |
449 | s->physical_offset += did_read; | |
450 | s->active = did_read; | |
451 | did_read = (did_read > to_read) ? to_read : did_read; | |
452 | memcpy (p, s->buffer, did_read); | |
453 | } | |
454 | else | |
455 | { | |
456 | did_read = raw_read (s, p, to_read); | |
457 | s->physical_offset += did_read; | |
458 | s->active = 0; | |
459 | } | |
460 | nbyte = did_read + nread; | |
6de9cd9a | 461 | } |
7812c78c JD |
462 | s->logical_offset += nbyte; |
463 | return nbyte; | |
6de9cd9a DN |
464 | } |
465 | ||
7812c78c JD |
466 | static ssize_t |
467 | buf_write (unix_stream * s, const void * buf, ssize_t nbyte) | |
6de9cd9a | 468 | { |
7812c78c JD |
469 | if (s->ndirty == 0) |
470 | s->buffer_offset = s->logical_offset; | |
471 | ||
472 | /* Does the data fit into the buffer? As a special case, if the | |
473 | buffer is empty and the request is bigger than BUFFER_SIZE/2, | |
474 | write directly. This avoids the case where the buffer would have | |
475 | to be flushed at every write. */ | |
476 | if (!(s->ndirty == 0 && nbyte > BUFFER_SIZE/2) | |
477 | && s->logical_offset + nbyte <= s->buffer_offset + BUFFER_SIZE | |
478 | && s->buffer_offset <= s->logical_offset | |
479 | && s->buffer_offset + s->ndirty >= s->logical_offset) | |
c1d70e1a | 480 | { |
7812c78c JD |
481 | memcpy (s->buffer + (s->logical_offset - s->buffer_offset), buf, nbyte); |
482 | int nd = (s->logical_offset - s->buffer_offset) + nbyte; | |
483 | if (nd > s->ndirty) | |
484 | s->ndirty = nd; | |
c1d70e1a TK |
485 | } |
486 | else | |
487 | { | |
7812c78c JD |
488 | /* Flush, and either fill the buffer with the new data, or if |
489 | the request is bigger than the buffer size, write directly | |
490 | bypassing the buffer. */ | |
491 | buf_flush (s); | |
492 | if (nbyte <= BUFFER_SIZE/2) | |
493 | { | |
494 | memcpy (s->buffer, buf, nbyte); | |
495 | s->buffer_offset = s->logical_offset; | |
496 | s->ndirty += nbyte; | |
497 | } | |
498 | else | |
499 | { | |
500 | if (s->file_length != -1 && s->physical_offset != s->logical_offset | |
501 | && lseek (s->fd, s->logical_offset, SEEK_SET) < 0) | |
502 | return -1; | |
503 | nbyte = raw_write (s, buf, nbyte); | |
504 | s->physical_offset += nbyte; | |
505 | } | |
6de9cd9a | 506 | } |
7812c78c | 507 | s->logical_offset += nbyte; |
779f3975 | 508 | /* Don't increment file_length if the file is non-seekable. */ |
779f3975 | 509 | if (s->file_length != -1 && s->logical_offset > s->file_length) |
7812c78c JD |
510 | s->file_length = s->logical_offset; |
511 | return nbyte; | |
6de9cd9a DN |
512 | } |
513 | ||
a4384bad JB |
514 | static gfc_offset |
515 | buf_seek (unix_stream * s, gfc_offset offset, int whence) | |
6de9cd9a | 516 | { |
7812c78c | 517 | switch (whence) |
779f3975 | 518 | { |
7812c78c JD |
519 | case SEEK_SET: |
520 | break; | |
521 | case SEEK_CUR: | |
522 | offset += s->logical_offset; | |
523 | break; | |
524 | case SEEK_END: | |
525 | offset += s->file_length; | |
526 | break; | |
527 | default: | |
528 | return -1; | |
779f3975 | 529 | } |
7812c78c | 530 | if (offset < 0) |
802fc826 | 531 | { |
7812c78c JD |
532 | errno = EINVAL; |
533 | return -1; | |
802fc826 | 534 | } |
7812c78c JD |
535 | s->logical_offset = offset; |
536 | return offset; | |
6de9cd9a DN |
537 | } |
538 | ||
a4384bad | 539 | static gfc_offset |
7812c78c | 540 | buf_tell (unix_stream * s) |
82b8244c | 541 | { |
7812c78c | 542 | return s->logical_offset; |
82b8244c | 543 | } |
0dc43461 | 544 | |
0dc43461 | 545 | static int |
a4384bad | 546 | buf_truncate (unix_stream * s, gfc_offset length) |
0dc43461 | 547 | { |
7812c78c | 548 | int r; |
0dc43461 | 549 | |
7812c78c JD |
550 | if (buf_flush (s) != 0) |
551 | return -1; | |
552 | r = raw_truncate (s, length); | |
553 | if (r == 0) | |
554 | s->file_length = length; | |
555 | return r; | |
0dc43461 JB |
556 | } |
557 | ||
0dc43461 | 558 | static int |
7812c78c | 559 | buf_close (unix_stream * s) |
6de9cd9a | 560 | { |
7812c78c JD |
561 | if (buf_flush (s) != 0) |
562 | return -1; | |
563 | free_mem (s->buffer); | |
564 | return raw_close (s); | |
6de9cd9a DN |
565 | } |
566 | ||
7812c78c JD |
567 | static int |
568 | buf_init (unix_stream * s) | |
6de9cd9a | 569 | { |
7812c78c JD |
570 | s->st.read = (void *) buf_read; |
571 | s->st.write = (void *) buf_write; | |
572 | s->st.seek = (void *) buf_seek; | |
573 | s->st.tell = (void *) buf_tell; | |
d26014d2 | 574 | s->st.trunc = (void *) buf_truncate; |
7812c78c JD |
575 | s->st.close = (void *) buf_close; |
576 | s->st.flush = (void *) buf_flush; | |
6de9cd9a | 577 | |
7812c78c JD |
578 | s->buffer = get_mem (BUFFER_SIZE); |
579 | return 0; | |
6de9cd9a DN |
580 | } |
581 | ||
582 | ||
6de9cd9a DN |
583 | /********************************************************************* |
584 | memory stream functions - These are used for internal files | |
585 | ||
586 | The idea here is that a single stream structure is created and all | |
587 | requests must be satisfied from it. The location and size of the | |
588 | buffer is the character variable supplied to the READ or WRITE | |
589 | statement. | |
590 | ||
591 | *********************************************************************/ | |
592 | ||
593 | ||
7812c78c JD |
594 | char * |
595 | mem_alloc_r (stream * strm, int * len) | |
6de9cd9a | 596 | { |
7812c78c | 597 | unix_stream * s = (unix_stream *) strm; |
81f4be3c | 598 | gfc_offset n; |
15877a88 | 599 | gfc_offset where = s->logical_offset; |
6de9cd9a DN |
600 | |
601 | if (where < s->buffer_offset || where > s->buffer_offset + s->active) | |
602 | return NULL; | |
603 | ||
bd72d66c | 604 | n = s->buffer_offset + s->active - where; |
6de9cd9a DN |
605 | if (*len > n) |
606 | *len = n; | |
607 | ||
7812c78c JD |
608 | s->logical_offset = where + *len; |
609 | ||
6de9cd9a DN |
610 | return s->buffer + (where - s->buffer_offset); |
611 | } | |
612 | ||
613 | ||
7812c78c JD |
614 | char * |
615 | mem_alloc_w (stream * strm, int * len) | |
6de9cd9a | 616 | { |
7812c78c | 617 | unix_stream * s = (unix_stream *) strm; |
81f4be3c | 618 | gfc_offset m; |
15877a88 | 619 | gfc_offset where = s->logical_offset; |
6de9cd9a | 620 | |
6de9cd9a DN |
621 | m = where + *len; |
622 | ||
59154ed2 | 623 | if (where < s->buffer_offset) |
6de9cd9a DN |
624 | return NULL; |
625 | ||
59154ed2 | 626 | if (m > s->file_length) |
aed6ee24 | 627 | return NULL; |
59154ed2 | 628 | |
6de9cd9a DN |
629 | s->logical_offset = m; |
630 | ||
631 | return s->buffer + (where - s->buffer_offset); | |
632 | } | |
633 | ||
634 | ||
15877a88 | 635 | /* Stream read function for internal units. */ |
0dc43461 | 636 | |
7812c78c JD |
637 | static ssize_t |
638 | mem_read (stream * s, void * buf, ssize_t nbytes) | |
0dc43461 JB |
639 | { |
640 | void *p; | |
7812c78c | 641 | int nb = nbytes; |
0dc43461 | 642 | |
7812c78c | 643 | p = mem_alloc_r (s, &nb); |
0dc43461 JB |
644 | if (p) |
645 | { | |
7812c78c JD |
646 | memcpy (buf, p, nb); |
647 | return (ssize_t) nb; | |
0dc43461 JB |
648 | } |
649 | else | |
7812c78c | 650 | return 0; |
0dc43461 JB |
651 | } |
652 | ||
653 | ||
654 | /* Stream write function for internal units. This is not actually used | |
655 | at the moment, as all internal IO is formatted and the formatted IO | |
656 | routines use mem_alloc_w_at. */ | |
657 | ||
7812c78c JD |
658 | static ssize_t |
659 | mem_write (stream * s, const void * buf, ssize_t nbytes) | |
0dc43461 JB |
660 | { |
661 | void *p; | |
7812c78c | 662 | int nb = nbytes; |
0dc43461 | 663 | |
7812c78c | 664 | p = mem_alloc_w (s, &nb); |
0dc43461 JB |
665 | if (p) |
666 | { | |
7812c78c JD |
667 | memcpy (p, buf, nb); |
668 | return (ssize_t) nb; | |
0dc43461 JB |
669 | } |
670 | else | |
7812c78c | 671 | return 0; |
0dc43461 JB |
672 | } |
673 | ||
674 | ||
a4384bad JB |
675 | static gfc_offset |
676 | mem_seek (stream * strm, gfc_offset offset, int whence) | |
6de9cd9a | 677 | { |
7812c78c JD |
678 | unix_stream * s = (unix_stream *) strm; |
679 | switch (whence) | |
680 | { | |
681 | case SEEK_SET: | |
682 | break; | |
683 | case SEEK_CUR: | |
684 | offset += s->logical_offset; | |
685 | break; | |
686 | case SEEK_END: | |
687 | offset += s->file_length; | |
688 | break; | |
689 | default: | |
690 | return -1; | |
691 | } | |
692 | ||
693 | /* Note that for internal array I/O it's actually possible to have a | |
694 | negative offset, so don't check for that. */ | |
6de9cd9a DN |
695 | if (offset > s->file_length) |
696 | { | |
7812c78c JD |
697 | errno = EINVAL; |
698 | return -1; | |
6de9cd9a DN |
699 | } |
700 | ||
701 | s->logical_offset = offset; | |
7812c78c JD |
702 | |
703 | /* Returning < 0 is the error indicator for sseek(), so return 0 if | |
704 | offset is negative. Thus if the return value is 0, the caller | |
705 | has to use stell() to get the real value of logical_offset. */ | |
706 | if (offset >= 0) | |
707 | return offset; | |
708 | return 0; | |
6de9cd9a DN |
709 | } |
710 | ||
711 | ||
a4384bad | 712 | static gfc_offset |
7812c78c | 713 | mem_tell (stream * s) |
82b8244c | 714 | { |
7812c78c | 715 | return ((unix_stream *)s)->logical_offset; |
82b8244c JB |
716 | } |
717 | ||
718 | ||
6de9cd9a | 719 | static int |
7812c78c | 720 | mem_truncate (unix_stream * s __attribute__ ((unused)), |
a4384bad | 721 | gfc_offset length __attribute__ ((unused))) |
6de9cd9a | 722 | { |
7812c78c | 723 | return 0; |
6de9cd9a DN |
724 | } |
725 | ||
726 | ||
7812c78c JD |
727 | static int |
728 | mem_flush (unix_stream * s __attribute__ ((unused))) | |
6de9cd9a | 729 | { |
7812c78c | 730 | return 0; |
6de9cd9a DN |
731 | } |
732 | ||
733 | ||
7812c78c JD |
734 | static int |
735 | mem_close (unix_stream * s) | |
6de9cd9a | 736 | { |
7812c78c JD |
737 | if (s != NULL) |
738 | free_mem (s); | |
6de9cd9a | 739 | |
7812c78c JD |
740 | return 0; |
741 | } | |
6de9cd9a DN |
742 | |
743 | ||
744 | /********************************************************************* | |
745 | Public functions -- A reimplementation of this module needs to | |
746 | define functional equivalents of the following. | |
747 | *********************************************************************/ | |
748 | ||
749 | /* empty_internal_buffer()-- Zero the buffer of Internal file */ | |
750 | ||
751 | void | |
752 | empty_internal_buffer(stream *strm) | |
753 | { | |
7812c78c | 754 | unix_stream * s = (unix_stream *) strm; |
f21edfd6 | 755 | memset(s->buffer, ' ', s->file_length); |
6de9cd9a DN |
756 | } |
757 | ||
758 | /* open_internal()-- Returns a stream structure from an internal file */ | |
759 | ||
760 | stream * | |
9370b3c0 | 761 | open_internal (char *base, int length, gfc_offset offset) |
6de9cd9a | 762 | { |
7812c78c | 763 | unix_stream *s; |
6de9cd9a | 764 | |
7812c78c JD |
765 | s = get_mem (sizeof (unix_stream)); |
766 | memset (s, '\0', sizeof (unix_stream)); | |
6de9cd9a DN |
767 | |
768 | s->buffer = base; | |
9370b3c0 | 769 | s->buffer_offset = offset; |
6de9cd9a DN |
770 | |
771 | s->logical_offset = 0; | |
772 | s->active = s->file_length = length; | |
773 | ||
6de9cd9a DN |
774 | s->st.close = (void *) mem_close; |
775 | s->st.seek = (void *) mem_seek; | |
7812c78c | 776 | s->st.tell = (void *) mem_tell; |
d26014d2 | 777 | s->st.trunc = (void *) mem_truncate; |
0dc43461 JB |
778 | s->st.read = (void *) mem_read; |
779 | s->st.write = (void *) mem_write; | |
7812c78c | 780 | s->st.flush = (void *) mem_flush; |
6de9cd9a DN |
781 | |
782 | return (stream *) s; | |
783 | } | |
784 | ||
785 | ||
786 | /* fd_to_stream()-- Given an open file descriptor, build a stream | |
787 | * around it. */ | |
788 | ||
789 | static stream * | |
ca0d06ac | 790 | fd_to_stream (int fd, int prot) |
6de9cd9a | 791 | { |
c9828e78 | 792 | gfstat_t statbuf; |
6de9cd9a DN |
793 | unix_stream *s; |
794 | ||
795 | s = get_mem (sizeof (unix_stream)); | |
c42a19d5 | 796 | memset (s, '\0', sizeof (unix_stream)); |
6de9cd9a DN |
797 | |
798 | s->fd = fd; | |
799 | s->buffer_offset = 0; | |
800 | s->physical_offset = 0; | |
801 | s->logical_offset = 0; | |
802 | s->prot = prot; | |
803 | ||
804 | /* Get the current length of the file. */ | |
805 | ||
806 | fstat (fd, &statbuf); | |
779f3975 | 807 | |
a4384bad | 808 | if (lseek (fd, 0, SEEK_CUR) == (gfc_offset) -1) |
779f3975 JD |
809 | s->file_length = -1; |
810 | else | |
811 | s->file_length = S_ISREG (statbuf.st_mode) ? statbuf.st_size : -1; | |
812 | ||
5133e4b9 | 813 | s->special_file = !S_ISREG (statbuf.st_mode); |
6de9cd9a | 814 | |
7812c78c JD |
815 | if (isatty (s->fd) || options.all_unbuffered |
816 | ||(options.unbuffered_preconnected && | |
817 | (s->fd == STDIN_FILENO | |
818 | || s->fd == STDOUT_FILENO | |
819 | || s->fd == STDERR_FILENO))) | |
820 | raw_init (s); | |
821 | else | |
822 | buf_init (s); | |
6de9cd9a DN |
823 | |
824 | return (stream *) s; | |
825 | } | |
826 | ||
827 | ||
df65f093 SK |
828 | /* Given the Fortran unit number, convert it to a C file descriptor. */ |
829 | ||
830 | int | |
5e805e44 | 831 | unit_to_fd (int unit) |
df65f093 | 832 | { |
df65f093 | 833 | gfc_unit *us; |
5e805e44 | 834 | int fd; |
df65f093 | 835 | |
5e805e44 | 836 | us = find_unit (unit); |
df65f093 SK |
837 | if (us == NULL) |
838 | return -1; | |
839 | ||
5e805e44 JJ |
840 | fd = ((unix_stream *) us->s)->fd; |
841 | unlock_unit (us); | |
842 | return fd; | |
df65f093 SK |
843 | } |
844 | ||
845 | ||
6de9cd9a DN |
846 | /* unpack_filename()-- Given a fortran string and a pointer to a |
847 | * buffer that is PATH_MAX characters, convert the fortran string to a | |
848 | * C string in the buffer. Returns nonzero if this is not possible. */ | |
849 | ||
10c682a0 | 850 | int |
6de9cd9a DN |
851 | unpack_filename (char *cstring, const char *fstring, int len) |
852 | { | |
6de9cd9a DN |
853 | len = fstrlen (fstring, len); |
854 | if (len >= PATH_MAX) | |
855 | return 1; | |
856 | ||
857 | memmove (cstring, fstring, len); | |
858 | cstring[len] = '\0'; | |
859 | ||
860 | return 0; | |
861 | } | |
862 | ||
863 | ||
864 | /* tempfile()-- Generate a temporary filename for a scratch file and | |
865 | * open it. mkstemp() opens the file for reading and writing, but the | |
866 | * library mode prevents anything that is not allowed. The descriptor | |
41724e6a | 867 | * is returned, which is -1 on error. The template is pointed to by |
5e805e44 | 868 | * opp->file, which is copied into the unit structure |
6de9cd9a DN |
869 | * and freed later. */ |
870 | ||
871 | static int | |
5e805e44 | 872 | tempfile (st_parameter_open *opp) |
6de9cd9a DN |
873 | { |
874 | const char *tempdir; | |
875 | char *template; | |
876 | int fd; | |
877 | ||
878 | tempdir = getenv ("GFORTRAN_TMPDIR"); | |
879 | if (tempdir == NULL) | |
880 | tempdir = getenv ("TMP"); | |
e087fdd8 FXC |
881 | if (tempdir == NULL) |
882 | tempdir = getenv ("TEMP"); | |
6de9cd9a DN |
883 | if (tempdir == NULL) |
884 | tempdir = DEFAULT_TEMPDIR; | |
885 | ||
886 | template = get_mem (strlen (tempdir) + 20); | |
887 | ||
d8163f5c | 888 | sprintf (template, "%s/gfortrantmpXXXXXX", tempdir); |
41724e6a AL |
889 | |
890 | #ifdef HAVE_MKSTEMP | |
6de9cd9a DN |
891 | |
892 | fd = mkstemp (template); | |
893 | ||
41724e6a AL |
894 | #else /* HAVE_MKSTEMP */ |
895 | ||
896 | if (mktemp (template)) | |
897 | do | |
8824fd4c | 898 | #if defined(HAVE_CRLF) && defined(O_BINARY) |
3c127520 | 899 | fd = open (template, O_RDWR | O_CREAT | O_EXCL | O_BINARY, |
10256cbe | 900 | S_IREAD | S_IWRITE); |
3c127520 | 901 | #else |
e087fdd8 | 902 | fd = open (template, O_RDWR | O_CREAT | O_EXCL, S_IREAD | S_IWRITE); |
3c127520 | 903 | #endif |
41724e6a AL |
904 | while (!(fd == -1 && errno == EEXIST) && mktemp (template)); |
905 | else | |
906 | fd = -1; | |
907 | ||
908 | #endif /* HAVE_MKSTEMP */ | |
909 | ||
6de9cd9a DN |
910 | if (fd < 0) |
911 | free_mem (template); | |
912 | else | |
913 | { | |
5e805e44 JJ |
914 | opp->file = template; |
915 | opp->file_len = strlen (template); /* Don't include trailing nul */ | |
6de9cd9a DN |
916 | } |
917 | ||
918 | return fd; | |
919 | } | |
920 | ||
921 | ||
6ecf6dcb | 922 | /* regular_file()-- Open a regular file. |
d02b2c64 TK |
923 | * Change flags->action if it is ACTION_UNSPECIFIED on entry, |
924 | * unless an error occurs. | |
6ecf6dcb | 925 | * Returns the descriptor, which is less than zero on error. */ |
6de9cd9a DN |
926 | |
927 | static int | |
5e805e44 | 928 | regular_file (st_parameter_open *opp, unit_flags *flags) |
6de9cd9a DN |
929 | { |
930 | char path[PATH_MAX + 1]; | |
6de9cd9a | 931 | int mode; |
6ecf6dcb | 932 | int rwflag; |
d02b2c64 | 933 | int crflag; |
6ecf6dcb | 934 | int fd; |
6de9cd9a | 935 | |
5e805e44 | 936 | if (unpack_filename (path, opp->file, opp->file_len)) |
6de9cd9a DN |
937 | { |
938 | errno = ENOENT; /* Fake an OS error */ | |
939 | return -1; | |
940 | } | |
941 | ||
d8771b59 JD |
942 | #ifdef __CYGWIN__ |
943 | if (opp->file_len == 7) | |
944 | { | |
945 | if (strncmp (path, "CONOUT$", 7) == 0 | |
946 | || strncmp (path, "CONERR$", 7) == 0) | |
947 | { | |
948 | fd = open ("/dev/conout", O_WRONLY); | |
949 | flags->action = ACTION_WRITE; | |
950 | return fd; | |
951 | } | |
952 | } | |
953 | ||
954 | if (opp->file_len == 6 && strncmp (path, "CONIN$", 6) == 0) | |
955 | { | |
956 | fd = open ("/dev/conin", O_RDONLY); | |
957 | flags->action = ACTION_READ; | |
958 | return fd; | |
959 | } | |
960 | #endif | |
961 | ||
37d1bbbc JD |
962 | |
963 | #ifdef __MINGW32__ | |
964 | if (opp->file_len == 7) | |
965 | { | |
966 | if (strncmp (path, "CONOUT$", 7) == 0 | |
967 | || strncmp (path, "CONERR$", 7) == 0) | |
968 | { | |
969 | fd = open ("CONOUT$", O_WRONLY); | |
970 | flags->action = ACTION_WRITE; | |
971 | return fd; | |
972 | } | |
973 | } | |
974 | ||
975 | if (opp->file_len == 6 && strncmp (path, "CONIN$", 6) == 0) | |
976 | { | |
977 | fd = open ("CONIN$", O_RDONLY); | |
978 | flags->action = ACTION_READ; | |
979 | return fd; | |
980 | } | |
981 | #endif | |
982 | ||
6ecf6dcb | 983 | rwflag = 0; |
6de9cd9a | 984 | |
6ecf6dcb | 985 | switch (flags->action) |
6de9cd9a DN |
986 | { |
987 | case ACTION_READ: | |
6ecf6dcb | 988 | rwflag = O_RDONLY; |
6de9cd9a DN |
989 | break; |
990 | ||
991 | case ACTION_WRITE: | |
6ecf6dcb | 992 | rwflag = O_WRONLY; |
6de9cd9a DN |
993 | break; |
994 | ||
995 | case ACTION_READWRITE: | |
6ecf6dcb SE |
996 | case ACTION_UNSPECIFIED: |
997 | rwflag = O_RDWR; | |
6de9cd9a DN |
998 | break; |
999 | ||
1000 | default: | |
5e805e44 | 1001 | internal_error (&opp->common, "regular_file(): Bad action"); |
6de9cd9a DN |
1002 | } |
1003 | ||
6ecf6dcb | 1004 | switch (flags->status) |
6de9cd9a DN |
1005 | { |
1006 | case STATUS_NEW: | |
d02b2c64 | 1007 | crflag = O_CREAT | O_EXCL; |
6de9cd9a DN |
1008 | break; |
1009 | ||
d02b2c64 TK |
1010 | case STATUS_OLD: /* open will fail if the file does not exist*/ |
1011 | crflag = 0; | |
6de9cd9a DN |
1012 | break; |
1013 | ||
1014 | case STATUS_UNKNOWN: | |
1015 | case STATUS_SCRATCH: | |
d02b2c64 | 1016 | crflag = O_CREAT; |
6de9cd9a DN |
1017 | break; |
1018 | ||
1019 | case STATUS_REPLACE: | |
d70d13ac | 1020 | crflag = O_CREAT | O_TRUNC; |
6de9cd9a DN |
1021 | break; |
1022 | ||
1023 | default: | |
5e805e44 | 1024 | internal_error (&opp->common, "regular_file(): Bad status"); |
6de9cd9a DN |
1025 | } |
1026 | ||
6ecf6dcb | 1027 | /* rwflag |= O_LARGEFILE; */ |
6de9cd9a | 1028 | |
8824fd4c | 1029 | #if defined(HAVE_CRLF) && defined(O_BINARY) |
3c127520 FXC |
1030 | crflag |= O_BINARY; |
1031 | #endif | |
1032 | ||
6ecf6dcb | 1033 | mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH; |
d02b2c64 TK |
1034 | fd = open (path, rwflag | crflag, mode); |
1035 | if (flags->action != ACTION_UNSPECIFIED) | |
d70d13ac | 1036 | return fd; |
d02b2c64 TK |
1037 | |
1038 | if (fd >= 0) | |
6ecf6dcb | 1039 | { |
d02b2c64 TK |
1040 | flags->action = ACTION_READWRITE; |
1041 | return fd; | |
6ecf6dcb | 1042 | } |
d70d13ac | 1043 | if (errno != EACCES && errno != EROFS) |
d02b2c64 TK |
1044 | return fd; |
1045 | ||
1046 | /* retry for read-only access */ | |
1047 | rwflag = O_RDONLY; | |
1048 | fd = open (path, rwflag | crflag, mode); | |
1049 | if (fd >=0) | |
1050 | { | |
1051 | flags->action = ACTION_READ; | |
10256cbe | 1052 | return fd; /* success */ |
d02b2c64 TK |
1053 | } |
1054 | ||
1055 | if (errno != EACCES) | |
10256cbe | 1056 | return fd; /* failure */ |
d02b2c64 TK |
1057 | |
1058 | /* retry for write-only access */ | |
1059 | rwflag = O_WRONLY; | |
1060 | fd = open (path, rwflag | crflag, mode); | |
1061 | if (fd >=0) | |
1062 | { | |
1063 | flags->action = ACTION_WRITE; | |
10256cbe | 1064 | return fd; /* success */ |
d02b2c64 | 1065 | } |
10256cbe | 1066 | return fd; /* failure */ |
6de9cd9a DN |
1067 | } |
1068 | ||
1069 | ||
1070 | /* open_external()-- Open an external file, unix specific version. | |
6ecf6dcb | 1071 | * Change flags->action if it is ACTION_UNSPECIFIED on entry. |
6de9cd9a DN |
1072 | * Returns NULL on operating system error. */ |
1073 | ||
1074 | stream * | |
5e805e44 | 1075 | open_external (st_parameter_open *opp, unit_flags *flags) |
6de9cd9a DN |
1076 | { |
1077 | int fd, prot; | |
1078 | ||
6ecf6dcb SE |
1079 | if (flags->status == STATUS_SCRATCH) |
1080 | { | |
5e805e44 | 1081 | fd = tempfile (opp); |
6ecf6dcb | 1082 | if (flags->action == ACTION_UNSPECIFIED) |
10256cbe | 1083 | flags->action = ACTION_READWRITE; |
10c682a0 FXC |
1084 | |
1085 | #if HAVE_UNLINK_OPEN_FILE | |
6ecf6dcb | 1086 | /* We can unlink scratch files now and it will go away when closed. */ |
5e805e44 JJ |
1087 | if (fd >= 0) |
1088 | unlink (opp->file); | |
10c682a0 | 1089 | #endif |
6ecf6dcb SE |
1090 | } |
1091 | else | |
1092 | { | |
d02b2c64 TK |
1093 | /* regular_file resets flags->action if it is ACTION_UNSPECIFIED and |
1094 | * if it succeeds */ | |
5e805e44 | 1095 | fd = regular_file (opp, flags); |
6ecf6dcb | 1096 | } |
6de9cd9a DN |
1097 | |
1098 | if (fd < 0) | |
1099 | return NULL; | |
1100 | fd = fix_fd (fd); | |
1101 | ||
6ecf6dcb | 1102 | switch (flags->action) |
6de9cd9a DN |
1103 | { |
1104 | case ACTION_READ: | |
1105 | prot = PROT_READ; | |
1106 | break; | |
1107 | ||
1108 | case ACTION_WRITE: | |
1109 | prot = PROT_WRITE; | |
1110 | break; | |
1111 | ||
1112 | case ACTION_READWRITE: | |
1113 | prot = PROT_READ | PROT_WRITE; | |
1114 | break; | |
1115 | ||
1116 | default: | |
5e805e44 | 1117 | internal_error (&opp->common, "open_external(): Bad action"); |
6de9cd9a DN |
1118 | } |
1119 | ||
ca0d06ac | 1120 | return fd_to_stream (fd, prot); |
6de9cd9a DN |
1121 | } |
1122 | ||
1123 | ||
1124 | /* input_stream()-- Return a stream pointer to the default input stream. | |
1125 | * Called on initialization. */ | |
1126 | ||
1127 | stream * | |
1128 | input_stream (void) | |
1129 | { | |
ca0d06ac | 1130 | return fd_to_stream (STDIN_FILENO, PROT_READ); |
6de9cd9a DN |
1131 | } |
1132 | ||
1133 | ||
fbac3363 | 1134 | /* output_stream()-- Return a stream pointer to the default output stream. |
6de9cd9a DN |
1135 | * Called on initialization. */ |
1136 | ||
1137 | stream * | |
1138 | output_stream (void) | |
1139 | { | |
1f94e1d8 FXC |
1140 | stream * s; |
1141 | ||
6a7c793f DS |
1142 | #if defined(HAVE_CRLF) && defined(HAVE_SETMODE) |
1143 | setmode (STDOUT_FILENO, O_BINARY); | |
1144 | #endif | |
1f94e1d8 FXC |
1145 | |
1146 | s = fd_to_stream (STDOUT_FILENO, PROT_WRITE); | |
1f94e1d8 | 1147 | return s; |
6de9cd9a DN |
1148 | } |
1149 | ||
1150 | ||
fbac3363 DE |
1151 | /* error_stream()-- Return a stream pointer to the default error stream. |
1152 | * Called on initialization. */ | |
1153 | ||
1154 | stream * | |
1155 | error_stream (void) | |
1156 | { | |
1f94e1d8 FXC |
1157 | stream * s; |
1158 | ||
6a7c793f DS |
1159 | #if defined(HAVE_CRLF) && defined(HAVE_SETMODE) |
1160 | setmode (STDERR_FILENO, O_BINARY); | |
1161 | #endif | |
1f94e1d8 FXC |
1162 | |
1163 | s = fd_to_stream (STDERR_FILENO, PROT_WRITE); | |
1f94e1d8 | 1164 | return s; |
fbac3363 DE |
1165 | } |
1166 | ||
6de9cd9a | 1167 | |
d8163f5c TK |
1168 | /* st_vprintf()-- vprintf function for error output. To avoid buffer |
1169 | overruns, we limit the length of the buffer to ST_VPRINTF_SIZE. 2k | |
1170 | is big enough to completely fill a 80x25 terminal, so it shuld be | |
1171 | OK. We use a direct write() because it is simpler and least likely | |
f353733a TK |
1172 | to be clobbered by memory corruption. Writing an error message |
1173 | longer than that is an error. */ | |
6de9cd9a | 1174 | |
d8163f5c | 1175 | #define ST_VPRINTF_SIZE 2048 |
6de9cd9a | 1176 | |
d8163f5c TK |
1177 | int |
1178 | st_vprintf (const char *format, va_list ap) | |
1179 | { | |
1180 | static char buffer[ST_VPRINTF_SIZE]; | |
1181 | int written; | |
1182 | int fd; | |
6de9cd9a | 1183 | |
d8163f5c TK |
1184 | fd = options.use_stderr ? STDERR_FILENO : STDOUT_FILENO; |
1185 | #ifdef HAVE_VSNPRINTF | |
1186 | written = vsnprintf(buffer, ST_VPRINTF_SIZE, format, ap); | |
1187 | #else | |
f353733a TK |
1188 | written = vsprintf(buffer, format, ap); |
1189 | ||
1190 | if (written >= ST_VPRINTF_SIZE-1) | |
1191 | { | |
1192 | /* The error message was longer than our buffer. Ouch. Because | |
1193 | we may have messed up things badly, report the error and | |
1194 | quit. */ | |
1195 | #define ERROR_MESSAGE "Internal error: buffer overrun in st_vprintf()\n" | |
1196 | write (fd, buffer, ST_VPRINTF_SIZE-1); | |
1197 | write (fd, ERROR_MESSAGE, strlen(ERROR_MESSAGE)); | |
1198 | sys_exit(2); | |
1199 | #undef ERROR_MESSAGE | |
1200 | ||
1201 | } | |
d8163f5c | 1202 | #endif |
f353733a | 1203 | |
d8163f5c TK |
1204 | written = write (fd, buffer, written); |
1205 | return written; | |
6de9cd9a DN |
1206 | } |
1207 | ||
d8163f5c TK |
1208 | /* st_printf()-- printf() function for error output. This just calls |
1209 | st_vprintf() to do the actual work. */ | |
0dce3ca1 FXC |
1210 | |
1211 | int | |
1212 | st_printf (const char *format, ...) | |
1213 | { | |
d8163f5c TK |
1214 | int written; |
1215 | va_list ap; | |
1216 | va_start (ap, format); | |
1217 | written = st_vprintf(format, ap); | |
1218 | va_end (ap); | |
1219 | return written; | |
0dce3ca1 FXC |
1220 | } |
1221 | ||
6de9cd9a DN |
1222 | |
1223 | /* compare_file_filename()-- Given an open stream and a fortran string | |
1224 | * that is a filename, figure out if the file is the same as the | |
1225 | * filename. */ | |
1226 | ||
1227 | int | |
ad238e4f | 1228 | compare_file_filename (gfc_unit *u, const char *name, int len) |
6de9cd9a DN |
1229 | { |
1230 | char path[PATH_MAX + 1]; | |
c9828e78 | 1231 | gfstat_t st1; |
ad238e4f | 1232 | #ifdef HAVE_WORKING_STAT |
c9828e78 | 1233 | gfstat_t st2; |
fe046210 FXC |
1234 | #else |
1235 | # ifdef __MINGW32__ | |
1236 | uint64_t id1, id2; | |
1237 | # endif | |
ad238e4f | 1238 | #endif |
6de9cd9a DN |
1239 | |
1240 | if (unpack_filename (path, name, len)) | |
1241 | return 0; /* Can't be the same */ | |
1242 | ||
1243 | /* If the filename doesn't exist, then there is no match with the | |
1244 | * existing file. */ | |
1245 | ||
1246 | if (stat (path, &st1) < 0) | |
1247 | return 0; | |
1248 | ||
ad238e4f FXC |
1249 | #ifdef HAVE_WORKING_STAT |
1250 | fstat (((unix_stream *) (u->s))->fd, &st2); | |
6de9cd9a | 1251 | return (st1.st_dev == st2.st_dev) && (st1.st_ino == st2.st_ino); |
ad238e4f | 1252 | #else |
fe046210 FXC |
1253 | |
1254 | # ifdef __MINGW32__ | |
1255 | /* We try to match files by a unique ID. On some filesystems (network | |
1256 | fs and FAT), we can't generate this unique ID, and will simply compare | |
1257 | filenames. */ | |
1258 | id1 = id_from_path (path); | |
1259 | id2 = id_from_fd (((unix_stream *) (u->s))->fd); | |
1260 | if (id1 || id2) | |
1261 | return (id1 == id2); | |
1262 | # endif | |
1263 | ||
ad238e4f FXC |
1264 | if (len != u->file_len) |
1265 | return 0; | |
1266 | return (memcmp(path, u->file, len) == 0); | |
1267 | #endif | |
6de9cd9a DN |
1268 | } |
1269 | ||
1270 | ||
5e805e44 | 1271 | #ifdef HAVE_WORKING_STAT |
c9828e78 | 1272 | # define FIND_FILE0_DECL gfstat_t *st |
5e805e44 JJ |
1273 | # define FIND_FILE0_ARGS st |
1274 | #else | |
fe046210 FXC |
1275 | # define FIND_FILE0_DECL uint64_t id, const char *file, gfc_charlen_type file_len |
1276 | # define FIND_FILE0_ARGS id, file, file_len | |
5e805e44 JJ |
1277 | #endif |
1278 | ||
6de9cd9a DN |
1279 | /* find_file0()-- Recursive work function for find_file() */ |
1280 | ||
909087e0 | 1281 | static gfc_unit * |
5e805e44 | 1282 | find_file0 (gfc_unit *u, FIND_FILE0_DECL) |
6de9cd9a | 1283 | { |
909087e0 | 1284 | gfc_unit *v; |
fe046210 FXC |
1285 | #if defined(__MINGW32__) && !HAVE_WORKING_STAT |
1286 | uint64_t id1; | |
1287 | #endif | |
6de9cd9a DN |
1288 | |
1289 | if (u == NULL) | |
1290 | return NULL; | |
1291 | ||
ad238e4f | 1292 | #ifdef HAVE_WORKING_STAT |
5e805e44 JJ |
1293 | if (u->s != NULL |
1294 | && fstat (((unix_stream *) u->s)->fd, &st[1]) >= 0 && | |
1295 | st[0].st_dev == st[1].st_dev && st[0].st_ino == st[1].st_ino) | |
6de9cd9a | 1296 | return u; |
ad238e4f | 1297 | #else |
fe046210 FXC |
1298 | # ifdef __MINGW32__ |
1299 | if (u->s && ((id1 = id_from_fd (((unix_stream *) u->s)->fd)) || id1)) | |
1300 | { | |
1301 | if (id == id1) | |
1302 | return u; | |
1303 | } | |
1304 | else | |
1305 | # endif | |
1306 | if (compare_string (u->file_len, u->file, file_len, file) == 0) | |
1307 | return u; | |
ad238e4f | 1308 | #endif |
6de9cd9a | 1309 | |
5e805e44 | 1310 | v = find_file0 (u->left, FIND_FILE0_ARGS); |
6de9cd9a DN |
1311 | if (v != NULL) |
1312 | return v; | |
1313 | ||
5e805e44 | 1314 | v = find_file0 (u->right, FIND_FILE0_ARGS); |
6de9cd9a DN |
1315 | if (v != NULL) |
1316 | return v; | |
1317 | ||
1318 | return NULL; | |
1319 | } | |
1320 | ||
1321 | ||
1322 | /* find_file()-- Take the current filename and see if there is a unit | |
1323 | * that has the file already open. Returns a pointer to the unit if so. */ | |
1324 | ||
909087e0 | 1325 | gfc_unit * |
5e805e44 | 1326 | find_file (const char *file, gfc_charlen_type file_len) |
6de9cd9a DN |
1327 | { |
1328 | char path[PATH_MAX + 1]; | |
c9828e78 | 1329 | gfstat_t st[2]; |
5e805e44 | 1330 | gfc_unit *u; |
509f7fdc KT |
1331 | #if defined(__MINGW32__) && !HAVE_WORKING_STAT |
1332 | uint64_t id = 0ULL; | |
1333 | #endif | |
6de9cd9a | 1334 | |
5e805e44 | 1335 | if (unpack_filename (path, file, file_len)) |
6de9cd9a DN |
1336 | return NULL; |
1337 | ||
5e805e44 | 1338 | if (stat (path, &st[0]) < 0) |
6de9cd9a DN |
1339 | return NULL; |
1340 | ||
fe046210 | 1341 | #if defined(__MINGW32__) && !HAVE_WORKING_STAT |
509f7fdc | 1342 | id = id_from_path (path); |
fe046210 FXC |
1343 | #endif |
1344 | ||
5e805e44 JJ |
1345 | __gthread_mutex_lock (&unit_lock); |
1346 | retry: | |
1347 | u = find_file0 (unit_root, FIND_FILE0_ARGS); | |
1348 | if (u != NULL) | |
1349 | { | |
1350 | /* Fast path. */ | |
1351 | if (! __gthread_mutex_trylock (&u->lock)) | |
1352 | { | |
1353 | /* assert (u->closed == 0); */ | |
1354 | __gthread_mutex_unlock (&unit_lock); | |
1355 | return u; | |
1356 | } | |
1357 | ||
1358 | inc_waiting_locked (u); | |
1359 | } | |
1360 | __gthread_mutex_unlock (&unit_lock); | |
1361 | if (u != NULL) | |
1362 | { | |
1363 | __gthread_mutex_lock (&u->lock); | |
1364 | if (u->closed) | |
1365 | { | |
1366 | __gthread_mutex_lock (&unit_lock); | |
1367 | __gthread_mutex_unlock (&u->lock); | |
1368 | if (predec_waiting_locked (u) == 0) | |
1369 | free_mem (u); | |
1370 | goto retry; | |
1371 | } | |
1372 | ||
1373 | dec_waiting_unlocked (u); | |
1374 | } | |
1375 | return u; | |
1376 | } | |
1377 | ||
1378 | static gfc_unit * | |
1379 | flush_all_units_1 (gfc_unit *u, int min_unit) | |
1380 | { | |
1381 | while (u != NULL) | |
1382 | { | |
1383 | if (u->unit_number > min_unit) | |
1384 | { | |
1385 | gfc_unit *r = flush_all_units_1 (u->left, min_unit); | |
1386 | if (r != NULL) | |
1387 | return r; | |
1388 | } | |
1389 | if (u->unit_number >= min_unit) | |
1390 | { | |
1391 | if (__gthread_mutex_trylock (&u->lock)) | |
1392 | return u; | |
1393 | if (u->s) | |
7812c78c | 1394 | sflush (u->s); |
5e805e44 JJ |
1395 | __gthread_mutex_unlock (&u->lock); |
1396 | } | |
1397 | u = u->right; | |
1398 | } | |
1399 | return NULL; | |
1400 | } | |
1401 | ||
1402 | void | |
1403 | flush_all_units (void) | |
1404 | { | |
1405 | gfc_unit *u; | |
1406 | int min_unit = 0; | |
1407 | ||
1408 | __gthread_mutex_lock (&unit_lock); | |
1409 | do | |
1410 | { | |
1411 | u = flush_all_units_1 (unit_root, min_unit); | |
1412 | if (u != NULL) | |
1413 | inc_waiting_locked (u); | |
1414 | __gthread_mutex_unlock (&unit_lock); | |
1415 | if (u == NULL) | |
1416 | return; | |
1417 | ||
1418 | __gthread_mutex_lock (&u->lock); | |
1419 | ||
1420 | min_unit = u->unit_number + 1; | |
1421 | ||
1422 | if (u->closed == 0) | |
1423 | { | |
7812c78c | 1424 | sflush (u->s); |
5e805e44 JJ |
1425 | __gthread_mutex_lock (&unit_lock); |
1426 | __gthread_mutex_unlock (&u->lock); | |
1427 | (void) predec_waiting_locked (u); | |
1428 | } | |
1429 | else | |
1430 | { | |
1431 | __gthread_mutex_lock (&unit_lock); | |
1432 | __gthread_mutex_unlock (&u->lock); | |
1433 | if (predec_waiting_locked (u) == 0) | |
1434 | free_mem (u); | |
1435 | } | |
1436 | } | |
1437 | while (1); | |
6de9cd9a DN |
1438 | } |
1439 | ||
1440 | ||
6de9cd9a DN |
1441 | /* delete_file()-- Given a unit structure, delete the file associated |
1442 | * with the unit. Returns nonzero if something went wrong. */ | |
1443 | ||
1444 | int | |
909087e0 | 1445 | delete_file (gfc_unit * u) |
6de9cd9a DN |
1446 | { |
1447 | char path[PATH_MAX + 1]; | |
1448 | ||
1449 | if (unpack_filename (path, u->file, u->file_len)) | |
1450 | { /* Shouldn't be possible */ | |
1451 | errno = ENOENT; | |
1452 | return 1; | |
1453 | } | |
1454 | ||
1455 | return unlink (path); | |
1456 | } | |
1457 | ||
1458 | ||
1459 | /* file_exists()-- Returns nonzero if the current filename exists on | |
1460 | * the system */ | |
1461 | ||
1462 | int | |
5e805e44 | 1463 | file_exists (const char *file, gfc_charlen_type file_len) |
6de9cd9a DN |
1464 | { |
1465 | char path[PATH_MAX + 1]; | |
c9828e78 | 1466 | gfstat_t statbuf; |
6de9cd9a | 1467 | |
5e805e44 | 1468 | if (unpack_filename (path, file, file_len)) |
6de9cd9a DN |
1469 | return 0; |
1470 | ||
1471 | if (stat (path, &statbuf) < 0) | |
1472 | return 0; | |
1473 | ||
1474 | return 1; | |
1475 | } | |
1476 | ||
1477 | ||
41c3cddc JD |
1478 | /* file_size()-- Returns the size of the file. */ |
1479 | ||
1480 | GFC_IO_INT | |
1481 | file_size (const char *file, gfc_charlen_type file_len) | |
1482 | { | |
1483 | char path[PATH_MAX + 1]; | |
1484 | gfstat_t statbuf; | |
1485 | ||
1486 | if (unpack_filename (path, file, file_len)) | |
1487 | return -1; | |
1488 | ||
1489 | if (stat (path, &statbuf) < 0) | |
1490 | return -1; | |
1491 | ||
1492 | return (GFC_IO_INT) statbuf.st_size; | |
1493 | } | |
6de9cd9a | 1494 | |
09003779 | 1495 | static const char yes[] = "YES", no[] = "NO", unknown[] = "UNKNOWN"; |
6de9cd9a DN |
1496 | |
1497 | /* inquire_sequential()-- Given a fortran string, determine if the | |
1498 | * file is suitable for sequential access. Returns a C-style | |
1499 | * string. */ | |
1500 | ||
1501 | const char * | |
1502 | inquire_sequential (const char *string, int len) | |
1503 | { | |
1504 | char path[PATH_MAX + 1]; | |
c9828e78 | 1505 | gfstat_t statbuf; |
6de9cd9a DN |
1506 | |
1507 | if (string == NULL || | |
1508 | unpack_filename (path, string, len) || stat (path, &statbuf) < 0) | |
1509 | return unknown; | |
1510 | ||
1511 | if (S_ISREG (statbuf.st_mode) || | |
1512 | S_ISCHR (statbuf.st_mode) || S_ISFIFO (statbuf.st_mode)) | |
17c2c96c | 1513 | return unknown; |
6de9cd9a DN |
1514 | |
1515 | if (S_ISDIR (statbuf.st_mode) || S_ISBLK (statbuf.st_mode)) | |
1516 | return no; | |
1517 | ||
1518 | return unknown; | |
1519 | } | |
1520 | ||
1521 | ||
1522 | /* inquire_direct()-- Given a fortran string, determine if the file is | |
1523 | * suitable for direct access. Returns a C-style string. */ | |
1524 | ||
1525 | const char * | |
1526 | inquire_direct (const char *string, int len) | |
1527 | { | |
1528 | char path[PATH_MAX + 1]; | |
c9828e78 | 1529 | gfstat_t statbuf; |
6de9cd9a DN |
1530 | |
1531 | if (string == NULL || | |
1532 | unpack_filename (path, string, len) || stat (path, &statbuf) < 0) | |
1533 | return unknown; | |
1534 | ||
1535 | if (S_ISREG (statbuf.st_mode) || S_ISBLK (statbuf.st_mode)) | |
17c2c96c | 1536 | return unknown; |
6de9cd9a DN |
1537 | |
1538 | if (S_ISDIR (statbuf.st_mode) || | |
1539 | S_ISCHR (statbuf.st_mode) || S_ISFIFO (statbuf.st_mode)) | |
1540 | return no; | |
1541 | ||
1542 | return unknown; | |
1543 | } | |
1544 | ||
1545 | ||
1546 | /* inquire_formatted()-- Given a fortran string, determine if the file | |
1547 | * is suitable for formatted form. Returns a C-style string. */ | |
1548 | ||
1549 | const char * | |
1550 | inquire_formatted (const char *string, int len) | |
1551 | { | |
1552 | char path[PATH_MAX + 1]; | |
c9828e78 | 1553 | gfstat_t statbuf; |
6de9cd9a DN |
1554 | |
1555 | if (string == NULL || | |
1556 | unpack_filename (path, string, len) || stat (path, &statbuf) < 0) | |
1557 | return unknown; | |
1558 | ||
1559 | if (S_ISREG (statbuf.st_mode) || | |
1560 | S_ISBLK (statbuf.st_mode) || | |
1561 | S_ISCHR (statbuf.st_mode) || S_ISFIFO (statbuf.st_mode)) | |
17c2c96c | 1562 | return unknown; |
6de9cd9a DN |
1563 | |
1564 | if (S_ISDIR (statbuf.st_mode)) | |
1565 | return no; | |
1566 | ||
1567 | return unknown; | |
1568 | } | |
1569 | ||
1570 | ||
1571 | /* inquire_unformatted()-- Given a fortran string, determine if the file | |
1572 | * is suitable for unformatted form. Returns a C-style string. */ | |
1573 | ||
1574 | const char * | |
1575 | inquire_unformatted (const char *string, int len) | |
1576 | { | |
6de9cd9a DN |
1577 | return inquire_formatted (string, len); |
1578 | } | |
1579 | ||
1580 | ||
2515e5a7 FXC |
1581 | #ifndef HAVE_ACCESS |
1582 | ||
1583 | #ifndef W_OK | |
1584 | #define W_OK 2 | |
1585 | #endif | |
1586 | ||
1587 | #ifndef R_OK | |
1588 | #define R_OK 4 | |
1589 | #endif | |
1590 | ||
1591 | /* Fallback implementation of access() on systems that don't have it. | |
1592 | Only modes R_OK and W_OK are used in this file. */ | |
1593 | ||
1594 | static int | |
1595 | fallback_access (const char *path, int mode) | |
1596 | { | |
1597 | if ((mode & R_OK) && open (path, O_RDONLY) < 0) | |
1598 | return -1; | |
1599 | ||
1600 | if ((mode & W_OK) && open (path, O_WRONLY) < 0) | |
1601 | return -1; | |
1602 | ||
1603 | return 0; | |
1604 | } | |
1605 | ||
1606 | #undef access | |
1607 | #define access fallback_access | |
1608 | #endif | |
1609 | ||
1610 | ||
6de9cd9a DN |
1611 | /* inquire_access()-- Given a fortran string, determine if the file is |
1612 | * suitable for access. */ | |
1613 | ||
1614 | static const char * | |
1615 | inquire_access (const char *string, int len, int mode) | |
1616 | { | |
1617 | char path[PATH_MAX + 1]; | |
1618 | ||
1619 | if (string == NULL || unpack_filename (path, string, len) || | |
1620 | access (path, mode) < 0) | |
1621 | return no; | |
1622 | ||
1623 | return yes; | |
1624 | } | |
1625 | ||
1626 | ||
1627 | /* inquire_read()-- Given a fortran string, determine if the file is | |
1628 | * suitable for READ access. */ | |
1629 | ||
1630 | const char * | |
1631 | inquire_read (const char *string, int len) | |
1632 | { | |
6de9cd9a DN |
1633 | return inquire_access (string, len, R_OK); |
1634 | } | |
1635 | ||
1636 | ||
1637 | /* inquire_write()-- Given a fortran string, determine if the file is | |
1638 | * suitable for READ access. */ | |
1639 | ||
1640 | const char * | |
1641 | inquire_write (const char *string, int len) | |
1642 | { | |
6de9cd9a DN |
1643 | return inquire_access (string, len, W_OK); |
1644 | } | |
1645 | ||
1646 | ||
1647 | /* inquire_readwrite()-- Given a fortran string, determine if the file is | |
1648 | * suitable for read and write access. */ | |
1649 | ||
1650 | const char * | |
1651 | inquire_readwrite (const char *string, int len) | |
1652 | { | |
6de9cd9a DN |
1653 | return inquire_access (string, len, R_OK | W_OK); |
1654 | } | |
1655 | ||
1656 | ||
1657 | /* file_length()-- Return the file length in bytes, -1 if unknown */ | |
1658 | ||
81f4be3c | 1659 | gfc_offset |
6de9cd9a DN |
1660 | file_length (stream * s) |
1661 | { | |
a4384bad | 1662 | gfc_offset curr, end; |
7812c78c JD |
1663 | if (!is_seekable (s)) |
1664 | return -1; | |
1665 | curr = stell (s); | |
1666 | if (curr == -1) | |
1667 | return curr; | |
1668 | end = sseek (s, 0, SEEK_END); | |
1669 | sseek (s, curr, SEEK_SET); | |
1670 | return end; | |
6de9cd9a DN |
1671 | } |
1672 | ||
1673 | ||
1674 | /* is_seekable()-- Return nonzero if the stream is seekable, zero if | |
1675 | * it is not */ | |
1676 | ||
1677 | int | |
7ab8aa36 | 1678 | is_seekable (stream *s) |
6de9cd9a | 1679 | { |
0dc43461 JB |
1680 | /* By convention, if file_length == -1, the file is not |
1681 | seekable. */ | |
bf1df0a0 | 1682 | return ((unix_stream *) s)->file_length!=-1; |
6de9cd9a DN |
1683 | } |
1684 | ||
7ab8aa36 JD |
1685 | |
1686 | /* is_special()-- Return nonzero if the stream is not a regular file. */ | |
1687 | ||
9a7b6ea7 | 1688 | int |
7ab8aa36 JD |
1689 | is_special (stream *s) |
1690 | { | |
1691 | return ((unix_stream *) s)->special_file; | |
1692 | } | |
1693 | ||
1694 | ||
ae8b8789 FXC |
1695 | int |
1696 | stream_isatty (stream *s) | |
1697 | { | |
1698 | return isatty (((unix_stream *) s)->fd); | |
1699 | } | |
1700 | ||
1701 | char * | |
008afe51 | 1702 | stream_ttyname (stream *s __attribute__ ((unused))) |
ae8b8789 | 1703 | { |
8845001b | 1704 | #ifdef HAVE_TTYNAME |
ae8b8789 | 1705 | return ttyname (((unix_stream *) s)->fd); |
8845001b FXC |
1706 | #else |
1707 | return NULL; | |
1708 | #endif | |
ae8b8789 FXC |
1709 | } |
1710 | ||
6de9cd9a DN |
1711 | |
1712 | /* How files are stored: This is an operating-system specific issue, | |
1713 | and therefore belongs here. There are three cases to consider. | |
1714 | ||
1715 | Direct Access: | |
1716 | Records are written as block of bytes corresponding to the record | |
1717 | length of the file. This goes for both formatted and unformatted | |
1718 | records. Positioning is done explicitly for each data transfer, | |
1719 | so positioning is not much of an issue. | |
1720 | ||
1721 | Sequential Formatted: | |
1722 | Records are separated by newline characters. The newline character | |
1723 | is prohibited from appearing in a string. If it does, this will be | |
1724 | messed up on the next read. End of file is also the end of a record. | |
1725 | ||
1726 | Sequential Unformatted: | |
1727 | In this case, we are merely copying bytes to and from main storage, | |
1728 | yet we need to keep track of varying record lengths. We adopt | |
1729 | the solution used by f2c. Each record contains a pair of length | |
1730 | markers: | |
1731 | ||
10256cbe JD |
1732 | Length of record n in bytes |
1733 | Data of record n | |
1734 | Length of record n in bytes | |
6de9cd9a | 1735 | |
10256cbe JD |
1736 | Length of record n+1 in bytes |
1737 | Data of record n+1 | |
1738 | Length of record n+1 in bytes | |
6de9cd9a DN |
1739 | |
1740 | The length is stored at the end of a record to allow backspacing to the | |
1741 | previous record. Between data transfer statements, the file pointer | |
1742 | is left pointing to the first length of the current record. | |
1743 | ||
1744 | ENDFILE records are never explicitly stored. | |
1745 | ||
1746 | */ |