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5d38f366 | 1 | /* Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 |
a0007dfa | 2 | Free Software Foundation, Inc. |
4ee9c684 | 3 | Contributed by Andy Vaught |
84d33b91 | 4 | F2003 I/O support contributed by Jerry DeLisle |
4ee9c684 | 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 | |
6bc9506f | 10 | the Free Software Foundation; either version 3, or (at your option) |
4ee9c684 | 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 | ||
6bc9506f | 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/>. */ | |
4ee9c684 | 26 | |
27 | /* Unix stream I/O module */ | |
28 | ||
41f2d5e8 | 29 | #include "io.h" |
f65f6629 | 30 | #include "unix.h" |
4ee9c684 | 31 | #include <stdlib.h> |
32 | #include <limits.h> | |
33 | ||
34 | #include <unistd.h> | |
35 | #include <sys/stat.h> | |
36 | #include <fcntl.h> | |
2639e4cd | 37 | #include <assert.h> |
4ee9c684 | 38 | |
4ee9c684 | 39 | #include <string.h> |
40 | #include <errno.h> | |
41 | ||
c0ecd33c | 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. */ | |
7a4491a4 | 45 | #ifdef __MINGW32__ |
c0ecd33c | 46 | |
47 | #define WIN32_LEAN_AND_MEAN | |
48 | #include <windows.h> | |
49 | ||
4dbc0658 | 50 | #define lseek _lseeki64 |
7a4491a4 | 51 | #define fstat _fstati64 |
52 | #define stat _stati64 | |
53 | typedef struct _stati64 gfstat_t; | |
4dbc0658 | 54 | |
7a4491a4 | 55 | #ifndef HAVE_WORKING_STAT |
c0ecd33c | 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 | ||
7a4491a4 | 99 | #else |
100 | typedef struct stat gfstat_t; | |
101 | #endif | |
102 | ||
4ee9c684 | 103 | #ifndef PATH_MAX |
104 | #define PATH_MAX 1024 | |
105 | #endif | |
106 | ||
d2455565 | 107 | #ifndef PROT_READ |
108 | #define PROT_READ 1 | |
109 | #endif | |
110 | ||
111 | #ifndef PROT_WRITE | |
112 | #define PROT_WRITE 2 | |
113 | #endif | |
114 | ||
7dfba97b | 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 | ||
76c0a846 | 133 | |
65f15010 | 134 | /* Unix and internal stream I/O module */ |
76c0a846 | 135 | |
65f15010 | 136 | static const int BUFFER_SIZE = 8192; |
76c0a846 | 137 | |
138 | typedef struct | |
139 | { | |
140 | stream st; | |
141 | ||
76c0a846 | 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 */ | |
76c0a846 | 145 | gfc_offset file_length; /* Length of the file, -1 if not seekable. */ |
146 | ||
65f15010 | 147 | char *buffer; /* Pointer to the buffer. */ |
148 | int fd; /* The POSIX file descriptor. */ | |
149 | ||
76c0a846 | 150 | int active; /* Length of valid bytes in the buffer */ |
151 | ||
152 | int prot; | |
65f15010 | 153 | int ndirty; /* Dirty bytes starting at buffer_offset */ |
76c0a846 | 154 | |
155 | int special_file; /* =1 if the fd refers to a special file */ | |
76c0a846 | 156 | } |
157 | unix_stream; | |
158 | ||
71668ec3 | 159 | |
4ee9c684 | 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 | { | |
e0582811 | 170 | #ifdef HAVE_DUP |
4ee9c684 | 171 | int input, output, error; |
172 | ||
173 | input = output = error = 0; | |
174 | ||
7145fd06 | 175 | /* Unix allocates the lowest descriptors first, so a loop is not |
176 | required, but this order is. */ | |
4ee9c684 | 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); | |
e0582811 | 199 | #endif |
4ee9c684 | 200 | |
201 | return fd; | |
202 | } | |
203 | ||
204 | ||
2488b3b6 | 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 | ||
4ee9c684 | 222 | |
65f15010 | 223 | /* get_oserror()-- Get the most recent operating system error. For |
224 | * unix, this is errno. */ | |
b2a112ca | 225 | |
65f15010 | 226 | const char * |
227 | get_oserror (void) | |
4ee9c684 | 228 | { |
65f15010 | 229 | return strerror (errno); |
b2a112ca | 230 | } |
4ee9c684 | 231 | |
4ee9c684 | 232 | |
65f15010 | 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 | *********************************************************************/ | |
4ee9c684 | 244 | |
b2a112ca | 245 | static int |
65f15010 | 246 | raw_flush (unix_stream * s __attribute__ ((unused))) |
b2a112ca | 247 | { |
65f15010 | 248 | return 0; |
4ee9c684 | 249 | } |
250 | ||
65f15010 | 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 | } | |
4ee9c684 | 258 | |
65f15010 | 259 | static ssize_t |
260 | raw_write (unix_stream * s, const void * buf, ssize_t nbyte) | |
4ee9c684 | 261 | { |
65f15010 | 262 | ssize_t trans, bytes_left; |
b2a112ca | 263 | char *buf_st; |
b2a112ca | 264 | |
65f15010 | 265 | bytes_left = nbyte; |
b2a112ca | 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) | |
4ee9c684 | 271 | { |
65f15010 | 272 | trans = write (s->fd, buf_st, bytes_left); |
b2a112ca | 273 | if (trans < 0) |
274 | { | |
275 | if (errno == EINTR) | |
276 | continue; | |
277 | else | |
65f15010 | 278 | return trans; |
b2a112ca | 279 | } |
280 | buf_st += trans; | |
281 | bytes_left -= trans; | |
4ee9c684 | 282 | } |
283 | ||
65f15010 | 284 | return nbyte - bytes_left; |
4ee9c684 | 285 | } |
4ee9c684 | 286 | |
4dbc0658 | 287 | static gfc_offset |
288 | raw_seek (unix_stream * s, gfc_offset offset, int whence) | |
65f15010 | 289 | { |
290 | return lseek (s->fd, offset, whence); | |
291 | } | |
4ee9c684 | 292 | |
4dbc0658 | 293 | static gfc_offset |
65f15010 | 294 | raw_tell (unix_stream * s) |
295 | { | |
296 | return lseek (s->fd, 0, SEEK_CUR); | |
297 | } | |
4ee9c684 | 298 | |
65f15010 | 299 | static int |
4dbc0658 | 300 | raw_truncate (unix_stream * s, gfc_offset length) |
4ee9c684 | 301 | { |
4dbc0658 | 302 | #ifdef __MINGW32__ |
303 | HANDLE h; | |
304 | gfc_offset cur; | |
305 | ||
306 | if (isatty (s->fd)) | |
307 | { | |
308 | errno = EBADF; | |
309 | return -1; | |
310 | } | |
db23ac43 | 311 | h = (HANDLE) _get_osfhandle (s->fd); |
4dbc0658 | 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 | |
65f15010 | 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 | |
4ee9c684 | 341 | } |
342 | ||
65f15010 | 343 | static int |
344 | raw_close (unix_stream * s) | |
345 | { | |
346 | int retval; | |
347 | ||
8b89aa85 | 348 | if (s->fd != STDOUT_FILENO |
349 | && s->fd != STDERR_FILENO | |
350 | && s->fd != STDIN_FILENO) | |
351 | retval = close (s->fd); | |
352 | else | |
6ffeb312 | 353 | retval = 0; |
65f15010 | 354 | free_mem (s); |
355 | return retval; | |
356 | } | |
4ee9c684 | 357 | |
65f15010 | 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; | |
afd927a4 | 365 | s->st.trunc = (void *) raw_truncate; |
65f15010 | 366 | s->st.close = (void *) raw_close; |
367 | s->st.flush = (void *) raw_flush; | |
4ee9c684 | 368 | |
65f15010 | 369 | s->buffer = NULL; |
370 | return 0; | |
371 | } | |
b2a112ca | 372 | |
4ee9c684 | 373 | |
65f15010 | 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) | |
4ee9c684 | 383 | { |
65f15010 | 384 | int writelen; |
385 | ||
386 | /* Flushing in read mode means discarding read bytes. */ | |
387 | s->active = 0; | |
b2a112ca | 388 | |
4ee9c684 | 389 | if (s->ndirty == 0) |
65f15010 | 390 | return 0; |
352597f9 | 391 | |
65f15010 | 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; | |
4ee9c684 | 395 | |
65f15010 | 396 | writelen = raw_write (s, s->buffer, s->ndirty); |
4ee9c684 | 397 | |
65f15010 | 398 | s->physical_offset = s->buffer_offset + writelen; |
5a78b88f | 399 | |
65f15010 | 400 | /* Don't increment file_length if the file is non-seekable. */ |
5a78b88f | 401 | if (s->file_length != -1 && s->physical_offset > s->file_length) |
65f15010 | 402 | s->file_length = s->physical_offset; |
b2a112ca | 403 | |
404 | s->ndirty -= writelen; | |
405 | if (s->ndirty != 0) | |
65f15010 | 406 | return -1; |
4ee9c684 | 407 | |
65f15010 | 408 | return 0; |
4ee9c684 | 409 | } |
410 | ||
65f15010 | 411 | static ssize_t |
412 | buf_read (unix_stream * s, void * buf, ssize_t nbyte) | |
4ee9c684 | 413 | { |
65f15010 | 414 | if (s->active == 0) |
415 | s->buffer_offset = s->logical_offset; | |
5d5f00d5 | 416 | |
65f15010 | 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); | |
5d5f00d5 | 421 | else |
422 | { | |
65f15010 | 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; | |
4ee9c684 | 461 | } |
65f15010 | 462 | s->logical_offset += nbyte; |
463 | return nbyte; | |
4ee9c684 | 464 | } |
465 | ||
65f15010 | 466 | static ssize_t |
467 | buf_write (unix_stream * s, const void * buf, ssize_t nbyte) | |
4ee9c684 | 468 | { |
65f15010 | 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) | |
fef3501c | 480 | { |
65f15010 | 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; | |
fef3501c | 485 | } |
486 | else | |
487 | { | |
65f15010 | 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 | |
35a97371 | 499 | { |
500 | if (s->file_length != -1 && s->physical_offset != s->logical_offset) | |
501 | { | |
502 | if (lseek (s->fd, s->logical_offset, SEEK_SET) < 0) | |
503 | return -1; | |
504 | s->physical_offset = s->logical_offset; | |
505 | } | |
506 | ||
507 | nbyte = raw_write (s, buf, nbyte); | |
508 | s->physical_offset += nbyte; | |
509 | } | |
4ee9c684 | 510 | } |
65f15010 | 511 | s->logical_offset += nbyte; |
352597f9 | 512 | /* Don't increment file_length if the file is non-seekable. */ |
352597f9 | 513 | if (s->file_length != -1 && s->logical_offset > s->file_length) |
65f15010 | 514 | s->file_length = s->logical_offset; |
515 | return nbyte; | |
4ee9c684 | 516 | } |
517 | ||
4dbc0658 | 518 | static gfc_offset |
519 | buf_seek (unix_stream * s, gfc_offset offset, int whence) | |
4ee9c684 | 520 | { |
65f15010 | 521 | switch (whence) |
352597f9 | 522 | { |
65f15010 | 523 | case SEEK_SET: |
524 | break; | |
525 | case SEEK_CUR: | |
526 | offset += s->logical_offset; | |
527 | break; | |
528 | case SEEK_END: | |
529 | offset += s->file_length; | |
530 | break; | |
531 | default: | |
532 | return -1; | |
352597f9 | 533 | } |
65f15010 | 534 | if (offset < 0) |
72909c79 | 535 | { |
65f15010 | 536 | errno = EINVAL; |
537 | return -1; | |
72909c79 | 538 | } |
65f15010 | 539 | s->logical_offset = offset; |
540 | return offset; | |
4ee9c684 | 541 | } |
542 | ||
4dbc0658 | 543 | static gfc_offset |
65f15010 | 544 | buf_tell (unix_stream * s) |
56f281a2 | 545 | { |
65f15010 | 546 | return s->logical_offset; |
56f281a2 | 547 | } |
b2a112ca | 548 | |
b2a112ca | 549 | static int |
4dbc0658 | 550 | buf_truncate (unix_stream * s, gfc_offset length) |
b2a112ca | 551 | { |
65f15010 | 552 | int r; |
b2a112ca | 553 | |
65f15010 | 554 | if (buf_flush (s) != 0) |
555 | return -1; | |
556 | r = raw_truncate (s, length); | |
557 | if (r == 0) | |
558 | s->file_length = length; | |
559 | return r; | |
b2a112ca | 560 | } |
561 | ||
b2a112ca | 562 | static int |
65f15010 | 563 | buf_close (unix_stream * s) |
4ee9c684 | 564 | { |
65f15010 | 565 | if (buf_flush (s) != 0) |
566 | return -1; | |
567 | free_mem (s->buffer); | |
568 | return raw_close (s); | |
4ee9c684 | 569 | } |
570 | ||
65f15010 | 571 | static int |
572 | buf_init (unix_stream * s) | |
4ee9c684 | 573 | { |
65f15010 | 574 | s->st.read = (void *) buf_read; |
575 | s->st.write = (void *) buf_write; | |
576 | s->st.seek = (void *) buf_seek; | |
577 | s->st.tell = (void *) buf_tell; | |
afd927a4 | 578 | s->st.trunc = (void *) buf_truncate; |
65f15010 | 579 | s->st.close = (void *) buf_close; |
580 | s->st.flush = (void *) buf_flush; | |
4ee9c684 | 581 | |
65f15010 | 582 | s->buffer = get_mem (BUFFER_SIZE); |
583 | return 0; | |
4ee9c684 | 584 | } |
585 | ||
586 | ||
4ee9c684 | 587 | /********************************************************************* |
588 | memory stream functions - These are used for internal files | |
589 | ||
590 | The idea here is that a single stream structure is created and all | |
591 | requests must be satisfied from it. The location and size of the | |
592 | buffer is the character variable supplied to the READ or WRITE | |
593 | statement. | |
594 | ||
595 | *********************************************************************/ | |
596 | ||
597 | ||
65f15010 | 598 | char * |
599 | mem_alloc_r (stream * strm, int * len) | |
4ee9c684 | 600 | { |
65f15010 | 601 | unix_stream * s = (unix_stream *) strm; |
b093181d | 602 | gfc_offset n; |
d875179d | 603 | gfc_offset where = s->logical_offset; |
4ee9c684 | 604 | |
605 | if (where < s->buffer_offset || where > s->buffer_offset + s->active) | |
606 | return NULL; | |
607 | ||
11de4bf9 | 608 | n = s->buffer_offset + s->active - where; |
4ee9c684 | 609 | if (*len > n) |
610 | *len = n; | |
611 | ||
65f15010 | 612 | s->logical_offset = where + *len; |
613 | ||
4ee9c684 | 614 | return s->buffer + (where - s->buffer_offset); |
615 | } | |
616 | ||
617 | ||
65f15010 | 618 | char * |
619 | mem_alloc_w (stream * strm, int * len) | |
4ee9c684 | 620 | { |
65f15010 | 621 | unix_stream * s = (unix_stream *) strm; |
b093181d | 622 | gfc_offset m; |
d875179d | 623 | gfc_offset where = s->logical_offset; |
4ee9c684 | 624 | |
4ee9c684 | 625 | m = where + *len; |
626 | ||
2639e4cd | 627 | if (where < s->buffer_offset) |
4ee9c684 | 628 | return NULL; |
629 | ||
2639e4cd | 630 | if (m > s->file_length) |
72231bd6 | 631 | return NULL; |
2639e4cd | 632 | |
4ee9c684 | 633 | s->logical_offset = m; |
634 | ||
635 | return s->buffer + (where - s->buffer_offset); | |
636 | } | |
637 | ||
638 | ||
d875179d | 639 | /* Stream read function for internal units. */ |
b2a112ca | 640 | |
65f15010 | 641 | static ssize_t |
642 | mem_read (stream * s, void * buf, ssize_t nbytes) | |
b2a112ca | 643 | { |
644 | void *p; | |
65f15010 | 645 | int nb = nbytes; |
b2a112ca | 646 | |
65f15010 | 647 | p = mem_alloc_r (s, &nb); |
b2a112ca | 648 | if (p) |
649 | { | |
65f15010 | 650 | memcpy (buf, p, nb); |
651 | return (ssize_t) nb; | |
b2a112ca | 652 | } |
653 | else | |
65f15010 | 654 | return 0; |
b2a112ca | 655 | } |
656 | ||
657 | ||
658 | /* Stream write function for internal units. This is not actually used | |
659 | at the moment, as all internal IO is formatted and the formatted IO | |
660 | routines use mem_alloc_w_at. */ | |
661 | ||
65f15010 | 662 | static ssize_t |
663 | mem_write (stream * s, const void * buf, ssize_t nbytes) | |
b2a112ca | 664 | { |
665 | void *p; | |
65f15010 | 666 | int nb = nbytes; |
b2a112ca | 667 | |
65f15010 | 668 | p = mem_alloc_w (s, &nb); |
b2a112ca | 669 | if (p) |
670 | { | |
65f15010 | 671 | memcpy (p, buf, nb); |
672 | return (ssize_t) nb; | |
b2a112ca | 673 | } |
674 | else | |
65f15010 | 675 | return 0; |
b2a112ca | 676 | } |
677 | ||
678 | ||
4dbc0658 | 679 | static gfc_offset |
680 | mem_seek (stream * strm, gfc_offset offset, int whence) | |
4ee9c684 | 681 | { |
65f15010 | 682 | unix_stream * s = (unix_stream *) strm; |
683 | switch (whence) | |
684 | { | |
685 | case SEEK_SET: | |
686 | break; | |
687 | case SEEK_CUR: | |
688 | offset += s->logical_offset; | |
689 | break; | |
690 | case SEEK_END: | |
691 | offset += s->file_length; | |
692 | break; | |
693 | default: | |
694 | return -1; | |
695 | } | |
696 | ||
697 | /* Note that for internal array I/O it's actually possible to have a | |
698 | negative offset, so don't check for that. */ | |
4ee9c684 | 699 | if (offset > s->file_length) |
700 | { | |
65f15010 | 701 | errno = EINVAL; |
702 | return -1; | |
4ee9c684 | 703 | } |
704 | ||
705 | s->logical_offset = offset; | |
65f15010 | 706 | |
707 | /* Returning < 0 is the error indicator for sseek(), so return 0 if | |
708 | offset is negative. Thus if the return value is 0, the caller | |
709 | has to use stell() to get the real value of logical_offset. */ | |
710 | if (offset >= 0) | |
711 | return offset; | |
712 | return 0; | |
4ee9c684 | 713 | } |
714 | ||
715 | ||
4dbc0658 | 716 | static gfc_offset |
65f15010 | 717 | mem_tell (stream * s) |
56f281a2 | 718 | { |
65f15010 | 719 | return ((unix_stream *)s)->logical_offset; |
56f281a2 | 720 | } |
721 | ||
722 | ||
4ee9c684 | 723 | static int |
65f15010 | 724 | mem_truncate (unix_stream * s __attribute__ ((unused)), |
4dbc0658 | 725 | gfc_offset length __attribute__ ((unused))) |
4ee9c684 | 726 | { |
65f15010 | 727 | return 0; |
4ee9c684 | 728 | } |
729 | ||
730 | ||
65f15010 | 731 | static int |
732 | mem_flush (unix_stream * s __attribute__ ((unused))) | |
4ee9c684 | 733 | { |
65f15010 | 734 | return 0; |
4ee9c684 | 735 | } |
736 | ||
737 | ||
65f15010 | 738 | static int |
739 | mem_close (unix_stream * s) | |
4ee9c684 | 740 | { |
65f15010 | 741 | if (s != NULL) |
742 | free_mem (s); | |
4ee9c684 | 743 | |
65f15010 | 744 | return 0; |
745 | } | |
4ee9c684 | 746 | |
747 | ||
748 | /********************************************************************* | |
749 | Public functions -- A reimplementation of this module needs to | |
750 | define functional equivalents of the following. | |
751 | *********************************************************************/ | |
752 | ||
753 | /* empty_internal_buffer()-- Zero the buffer of Internal file */ | |
754 | ||
755 | void | |
756 | empty_internal_buffer(stream *strm) | |
757 | { | |
65f15010 | 758 | unix_stream * s = (unix_stream *) strm; |
7145fd06 | 759 | memset(s->buffer, ' ', s->file_length); |
4ee9c684 | 760 | } |
761 | ||
762 | /* open_internal()-- Returns a stream structure from an internal file */ | |
763 | ||
764 | stream * | |
cf4abc57 | 765 | open_internal (char *base, int length, gfc_offset offset) |
4ee9c684 | 766 | { |
65f15010 | 767 | unix_stream *s; |
4ee9c684 | 768 | |
65f15010 | 769 | s = get_mem (sizeof (unix_stream)); |
770 | memset (s, '\0', sizeof (unix_stream)); | |
4ee9c684 | 771 | |
772 | s->buffer = base; | |
cf4abc57 | 773 | s->buffer_offset = offset; |
4ee9c684 | 774 | |
775 | s->logical_offset = 0; | |
776 | s->active = s->file_length = length; | |
777 | ||
4ee9c684 | 778 | s->st.close = (void *) mem_close; |
779 | s->st.seek = (void *) mem_seek; | |
65f15010 | 780 | s->st.tell = (void *) mem_tell; |
afd927a4 | 781 | s->st.trunc = (void *) mem_truncate; |
b2a112ca | 782 | s->st.read = (void *) mem_read; |
783 | s->st.write = (void *) mem_write; | |
65f15010 | 784 | s->st.flush = (void *) mem_flush; |
4ee9c684 | 785 | |
786 | return (stream *) s; | |
787 | } | |
788 | ||
789 | ||
790 | /* fd_to_stream()-- Given an open file descriptor, build a stream | |
791 | * around it. */ | |
792 | ||
793 | static stream * | |
f0b5d33f | 794 | fd_to_stream (int fd, int prot) |
4ee9c684 | 795 | { |
7a4491a4 | 796 | gfstat_t statbuf; |
4ee9c684 | 797 | unix_stream *s; |
798 | ||
799 | s = get_mem (sizeof (unix_stream)); | |
8f8ad899 | 800 | memset (s, '\0', sizeof (unix_stream)); |
4ee9c684 | 801 | |
802 | s->fd = fd; | |
803 | s->buffer_offset = 0; | |
804 | s->physical_offset = 0; | |
805 | s->logical_offset = 0; | |
806 | s->prot = prot; | |
807 | ||
808 | /* Get the current length of the file. */ | |
809 | ||
810 | fstat (fd, &statbuf); | |
352597f9 | 811 | |
4dbc0658 | 812 | if (lseek (fd, 0, SEEK_CUR) == (gfc_offset) -1) |
352597f9 | 813 | s->file_length = -1; |
814 | else | |
815 | s->file_length = S_ISREG (statbuf.st_mode) ? statbuf.st_size : -1; | |
816 | ||
227e9423 | 817 | s->special_file = !S_ISREG (statbuf.st_mode); |
4ee9c684 | 818 | |
65f15010 | 819 | if (isatty (s->fd) || options.all_unbuffered |
820 | ||(options.unbuffered_preconnected && | |
821 | (s->fd == STDIN_FILENO | |
822 | || s->fd == STDOUT_FILENO | |
823 | || s->fd == STDERR_FILENO))) | |
824 | raw_init (s); | |
825 | else | |
826 | buf_init (s); | |
4ee9c684 | 827 | |
828 | return (stream *) s; | |
829 | } | |
830 | ||
831 | ||
771c1b50 | 832 | /* Given the Fortran unit number, convert it to a C file descriptor. */ |
833 | ||
834 | int | |
60c514ba | 835 | unit_to_fd (int unit) |
771c1b50 | 836 | { |
771c1b50 | 837 | gfc_unit *us; |
60c514ba | 838 | int fd; |
771c1b50 | 839 | |
60c514ba | 840 | us = find_unit (unit); |
771c1b50 | 841 | if (us == NULL) |
842 | return -1; | |
843 | ||
60c514ba | 844 | fd = ((unix_stream *) us->s)->fd; |
845 | unlock_unit (us); | |
846 | return fd; | |
771c1b50 | 847 | } |
848 | ||
849 | ||
4ee9c684 | 850 | /* unpack_filename()-- Given a fortran string and a pointer to a |
851 | * buffer that is PATH_MAX characters, convert the fortran string to a | |
852 | * C string in the buffer. Returns nonzero if this is not possible. */ | |
853 | ||
1dc95e51 | 854 | int |
4ee9c684 | 855 | unpack_filename (char *cstring, const char *fstring, int len) |
856 | { | |
4ee9c684 | 857 | len = fstrlen (fstring, len); |
858 | if (len >= PATH_MAX) | |
859 | return 1; | |
860 | ||
861 | memmove (cstring, fstring, len); | |
862 | cstring[len] = '\0'; | |
863 | ||
864 | return 0; | |
865 | } | |
866 | ||
867 | ||
868 | /* tempfile()-- Generate a temporary filename for a scratch file and | |
869 | * open it. mkstemp() opens the file for reading and writing, but the | |
870 | * library mode prevents anything that is not allowed. The descriptor | |
7dfba97b | 871 | * is returned, which is -1 on error. The template is pointed to by |
60c514ba | 872 | * opp->file, which is copied into the unit structure |
4ee9c684 | 873 | * and freed later. */ |
874 | ||
875 | static int | |
60c514ba | 876 | tempfile (st_parameter_open *opp) |
4ee9c684 | 877 | { |
878 | const char *tempdir; | |
879 | char *template; | |
db23ac43 | 880 | const char *slash = "/"; |
4ee9c684 | 881 | int fd; |
882 | ||
883 | tempdir = getenv ("GFORTRAN_TMPDIR"); | |
db23ac43 | 884 | #ifdef __MINGW32__ |
885 | if (tempdir == NULL) | |
886 | { | |
887 | char buffer[MAX_PATH + 1]; | |
888 | DWORD ret; | |
889 | ret = GetTempPath (MAX_PATH, buffer); | |
890 | /* If we are not able to get a temp-directory, we use | |
891 | current directory. */ | |
892 | if (ret > MAX_PATH || !ret) | |
893 | buffer[0] = 0; | |
894 | else | |
895 | buffer[ret] = 0; | |
896 | tempdir = strdup (buffer); | |
897 | } | |
898 | #else | |
4ee9c684 | 899 | if (tempdir == NULL) |
900 | tempdir = getenv ("TMP"); | |
ac09d5cc | 901 | if (tempdir == NULL) |
902 | tempdir = getenv ("TEMP"); | |
4ee9c684 | 903 | if (tempdir == NULL) |
904 | tempdir = DEFAULT_TEMPDIR; | |
db23ac43 | 905 | #endif |
906 | /* Check for special case that tempdir contains slash | |
907 | or backslash at end. */ | |
908 | if (*tempdir == 0 || tempdir[strlen (tempdir) - 1] == '/' | |
909 | #ifdef __MINGW32__ | |
910 | || tempdir[strlen (tempdir) - 1] == '\\' | |
911 | #endif | |
912 | ) | |
913 | slash = ""; | |
4ee9c684 | 914 | |
915 | template = get_mem (strlen (tempdir) + 20); | |
916 | ||
7dfba97b | 917 | #ifdef HAVE_MKSTEMP |
db23ac43 | 918 | sprintf (template, "%s%sgfortrantmpXXXXXX", tempdir, slash); |
4ee9c684 | 919 | |
920 | fd = mkstemp (template); | |
921 | ||
7dfba97b | 922 | #else /* HAVE_MKSTEMP */ |
726fd258 | 923 | fd = -1; |
924 | do | |
925 | { | |
db23ac43 | 926 | sprintf (template, "%s%sgfortrantmpXXXXXX", tempdir, slash); |
726fd258 | 927 | if (!mktemp (template)) |
928 | break; | |
cf6a3896 | 929 | #if defined(HAVE_CRLF) && defined(O_BINARY) |
cf55c3cf | 930 | fd = open (template, O_RDWR | O_CREAT | O_EXCL | O_BINARY, |
84d33b91 | 931 | S_IREAD | S_IWRITE); |
cf55c3cf | 932 | #else |
ac09d5cc | 933 | fd = open (template, O_RDWR | O_CREAT | O_EXCL, S_IREAD | S_IWRITE); |
cf55c3cf | 934 | #endif |
726fd258 | 935 | } |
936 | while (fd == -1 && errno == EEXIST); | |
7dfba97b | 937 | #endif /* HAVE_MKSTEMP */ |
938 | ||
4ee9c684 | 939 | if (fd < 0) |
940 | free_mem (template); | |
941 | else | |
942 | { | |
60c514ba | 943 | opp->file = template; |
944 | opp->file_len = strlen (template); /* Don't include trailing nul */ | |
4ee9c684 | 945 | } |
946 | ||
947 | return fd; | |
948 | } | |
949 | ||
950 | ||
6d12c489 | 951 | /* regular_file()-- Open a regular file. |
2d6ba0f9 | 952 | * Change flags->action if it is ACTION_UNSPECIFIED on entry, |
953 | * unless an error occurs. | |
6d12c489 | 954 | * Returns the descriptor, which is less than zero on error. */ |
4ee9c684 | 955 | |
956 | static int | |
60c514ba | 957 | regular_file (st_parameter_open *opp, unit_flags *flags) |
4ee9c684 | 958 | { |
959 | char path[PATH_MAX + 1]; | |
4ee9c684 | 960 | int mode; |
6d12c489 | 961 | int rwflag; |
2d6ba0f9 | 962 | int crflag; |
6d12c489 | 963 | int fd; |
4ee9c684 | 964 | |
60c514ba | 965 | if (unpack_filename (path, opp->file, opp->file_len)) |
4ee9c684 | 966 | { |
967 | errno = ENOENT; /* Fake an OS error */ | |
968 | return -1; | |
969 | } | |
970 | ||
3d17984e | 971 | #ifdef __CYGWIN__ |
972 | if (opp->file_len == 7) | |
973 | { | |
974 | if (strncmp (path, "CONOUT$", 7) == 0 | |
975 | || strncmp (path, "CONERR$", 7) == 0) | |
976 | { | |
977 | fd = open ("/dev/conout", O_WRONLY); | |
978 | flags->action = ACTION_WRITE; | |
979 | return fd; | |
980 | } | |
981 | } | |
982 | ||
983 | if (opp->file_len == 6 && strncmp (path, "CONIN$", 6) == 0) | |
984 | { | |
985 | fd = open ("/dev/conin", O_RDONLY); | |
986 | flags->action = ACTION_READ; | |
987 | return fd; | |
988 | } | |
989 | #endif | |
990 | ||
2058bc7e | 991 | |
992 | #ifdef __MINGW32__ | |
993 | if (opp->file_len == 7) | |
994 | { | |
995 | if (strncmp (path, "CONOUT$", 7) == 0 | |
996 | || strncmp (path, "CONERR$", 7) == 0) | |
997 | { | |
998 | fd = open ("CONOUT$", O_WRONLY); | |
999 | flags->action = ACTION_WRITE; | |
1000 | return fd; | |
1001 | } | |
1002 | } | |
1003 | ||
1004 | if (opp->file_len == 6 && strncmp (path, "CONIN$", 6) == 0) | |
1005 | { | |
1006 | fd = open ("CONIN$", O_RDONLY); | |
1007 | flags->action = ACTION_READ; | |
1008 | return fd; | |
1009 | } | |
1010 | #endif | |
1011 | ||
6d12c489 | 1012 | rwflag = 0; |
4ee9c684 | 1013 | |
6d12c489 | 1014 | switch (flags->action) |
4ee9c684 | 1015 | { |
1016 | case ACTION_READ: | |
6d12c489 | 1017 | rwflag = O_RDONLY; |
4ee9c684 | 1018 | break; |
1019 | ||
1020 | case ACTION_WRITE: | |
6d12c489 | 1021 | rwflag = O_WRONLY; |
4ee9c684 | 1022 | break; |
1023 | ||
1024 | case ACTION_READWRITE: | |
6d12c489 | 1025 | case ACTION_UNSPECIFIED: |
1026 | rwflag = O_RDWR; | |
4ee9c684 | 1027 | break; |
1028 | ||
1029 | default: | |
60c514ba | 1030 | internal_error (&opp->common, "regular_file(): Bad action"); |
4ee9c684 | 1031 | } |
1032 | ||
6d12c489 | 1033 | switch (flags->status) |
4ee9c684 | 1034 | { |
1035 | case STATUS_NEW: | |
2d6ba0f9 | 1036 | crflag = O_CREAT | O_EXCL; |
4ee9c684 | 1037 | break; |
1038 | ||
2d6ba0f9 | 1039 | case STATUS_OLD: /* open will fail if the file does not exist*/ |
1040 | crflag = 0; | |
4ee9c684 | 1041 | break; |
1042 | ||
1043 | case STATUS_UNKNOWN: | |
1044 | case STATUS_SCRATCH: | |
2d6ba0f9 | 1045 | crflag = O_CREAT; |
4ee9c684 | 1046 | break; |
1047 | ||
1048 | case STATUS_REPLACE: | |
a638be8f | 1049 | crflag = O_CREAT | O_TRUNC; |
4ee9c684 | 1050 | break; |
1051 | ||
1052 | default: | |
60c514ba | 1053 | internal_error (&opp->common, "regular_file(): Bad status"); |
4ee9c684 | 1054 | } |
1055 | ||
6d12c489 | 1056 | /* rwflag |= O_LARGEFILE; */ |
4ee9c684 | 1057 | |
cf6a3896 | 1058 | #if defined(HAVE_CRLF) && defined(O_BINARY) |
cf55c3cf | 1059 | crflag |= O_BINARY; |
1060 | #endif | |
1061 | ||
6d12c489 | 1062 | mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH; |
2d6ba0f9 | 1063 | fd = open (path, rwflag | crflag, mode); |
1064 | if (flags->action != ACTION_UNSPECIFIED) | |
a638be8f | 1065 | return fd; |
2d6ba0f9 | 1066 | |
1067 | if (fd >= 0) | |
6d12c489 | 1068 | { |
2d6ba0f9 | 1069 | flags->action = ACTION_READWRITE; |
1070 | return fd; | |
6d12c489 | 1071 | } |
a638be8f | 1072 | if (errno != EACCES && errno != EROFS) |
2d6ba0f9 | 1073 | return fd; |
1074 | ||
1075 | /* retry for read-only access */ | |
1076 | rwflag = O_RDONLY; | |
1077 | fd = open (path, rwflag | crflag, mode); | |
1078 | if (fd >=0) | |
1079 | { | |
1080 | flags->action = ACTION_READ; | |
84d33b91 | 1081 | return fd; /* success */ |
2d6ba0f9 | 1082 | } |
1083 | ||
1084 | if (errno != EACCES) | |
84d33b91 | 1085 | return fd; /* failure */ |
2d6ba0f9 | 1086 | |
1087 | /* retry for write-only access */ | |
1088 | rwflag = O_WRONLY; | |
1089 | fd = open (path, rwflag | crflag, mode); | |
1090 | if (fd >=0) | |
1091 | { | |
1092 | flags->action = ACTION_WRITE; | |
84d33b91 | 1093 | return fd; /* success */ |
2d6ba0f9 | 1094 | } |
84d33b91 | 1095 | return fd; /* failure */ |
4ee9c684 | 1096 | } |
1097 | ||
1098 | ||
1099 | /* open_external()-- Open an external file, unix specific version. | |
6d12c489 | 1100 | * Change flags->action if it is ACTION_UNSPECIFIED on entry. |
4ee9c684 | 1101 | * Returns NULL on operating system error. */ |
1102 | ||
1103 | stream * | |
60c514ba | 1104 | open_external (st_parameter_open *opp, unit_flags *flags) |
4ee9c684 | 1105 | { |
1106 | int fd, prot; | |
1107 | ||
6d12c489 | 1108 | if (flags->status == STATUS_SCRATCH) |
1109 | { | |
60c514ba | 1110 | fd = tempfile (opp); |
6d12c489 | 1111 | if (flags->action == ACTION_UNSPECIFIED) |
84d33b91 | 1112 | flags->action = ACTION_READWRITE; |
1dc95e51 | 1113 | |
1114 | #if HAVE_UNLINK_OPEN_FILE | |
6d12c489 | 1115 | /* We can unlink scratch files now and it will go away when closed. */ |
60c514ba | 1116 | if (fd >= 0) |
1117 | unlink (opp->file); | |
1dc95e51 | 1118 | #endif |
6d12c489 | 1119 | } |
1120 | else | |
1121 | { | |
2d6ba0f9 | 1122 | /* regular_file resets flags->action if it is ACTION_UNSPECIFIED and |
1123 | * if it succeeds */ | |
60c514ba | 1124 | fd = regular_file (opp, flags); |
6d12c489 | 1125 | } |
4ee9c684 | 1126 | |
1127 | if (fd < 0) | |
1128 | return NULL; | |
1129 | fd = fix_fd (fd); | |
1130 | ||
6d12c489 | 1131 | switch (flags->action) |
4ee9c684 | 1132 | { |
1133 | case ACTION_READ: | |
1134 | prot = PROT_READ; | |
1135 | break; | |
1136 | ||
1137 | case ACTION_WRITE: | |
1138 | prot = PROT_WRITE; | |
1139 | break; | |
1140 | ||
1141 | case ACTION_READWRITE: | |
1142 | prot = PROT_READ | PROT_WRITE; | |
1143 | break; | |
1144 | ||
1145 | default: | |
60c514ba | 1146 | internal_error (&opp->common, "open_external(): Bad action"); |
4ee9c684 | 1147 | } |
1148 | ||
f0b5d33f | 1149 | return fd_to_stream (fd, prot); |
4ee9c684 | 1150 | } |
1151 | ||
1152 | ||
1153 | /* input_stream()-- Return a stream pointer to the default input stream. | |
1154 | * Called on initialization. */ | |
1155 | ||
1156 | stream * | |
1157 | input_stream (void) | |
1158 | { | |
f0b5d33f | 1159 | return fd_to_stream (STDIN_FILENO, PROT_READ); |
4ee9c684 | 1160 | } |
1161 | ||
1162 | ||
ff81ee3b | 1163 | /* output_stream()-- Return a stream pointer to the default output stream. |
4ee9c684 | 1164 | * Called on initialization. */ |
1165 | ||
1166 | stream * | |
1167 | output_stream (void) | |
1168 | { | |
3e45a719 | 1169 | stream * s; |
1170 | ||
e693d7f1 | 1171 | #if defined(HAVE_CRLF) && defined(HAVE_SETMODE) |
1172 | setmode (STDOUT_FILENO, O_BINARY); | |
1173 | #endif | |
3e45a719 | 1174 | |
1175 | s = fd_to_stream (STDOUT_FILENO, PROT_WRITE); | |
3e45a719 | 1176 | return s; |
4ee9c684 | 1177 | } |
1178 | ||
1179 | ||
ff81ee3b | 1180 | /* error_stream()-- Return a stream pointer to the default error stream. |
1181 | * Called on initialization. */ | |
1182 | ||
1183 | stream * | |
1184 | error_stream (void) | |
1185 | { | |
3e45a719 | 1186 | stream * s; |
1187 | ||
e693d7f1 | 1188 | #if defined(HAVE_CRLF) && defined(HAVE_SETMODE) |
1189 | setmode (STDERR_FILENO, O_BINARY); | |
1190 | #endif | |
3e45a719 | 1191 | |
1192 | s = fd_to_stream (STDERR_FILENO, PROT_WRITE); | |
3e45a719 | 1193 | return s; |
ff81ee3b | 1194 | } |
1195 | ||
4ee9c684 | 1196 | |
5a037dbd | 1197 | /* st_vprintf()-- vprintf function for error output. To avoid buffer |
1198 | overruns, we limit the length of the buffer to ST_VPRINTF_SIZE. 2k | |
1199 | is big enough to completely fill a 80x25 terminal, so it shuld be | |
1200 | OK. We use a direct write() because it is simpler and least likely | |
0e80ec22 | 1201 | to be clobbered by memory corruption. Writing an error message |
1202 | longer than that is an error. */ | |
4ee9c684 | 1203 | |
5a037dbd | 1204 | #define ST_VPRINTF_SIZE 2048 |
4ee9c684 | 1205 | |
5a037dbd | 1206 | int |
1207 | st_vprintf (const char *format, va_list ap) | |
1208 | { | |
1209 | static char buffer[ST_VPRINTF_SIZE]; | |
1210 | int written; | |
1211 | int fd; | |
4ee9c684 | 1212 | |
5a037dbd | 1213 | fd = options.use_stderr ? STDERR_FILENO : STDOUT_FILENO; |
1214 | #ifdef HAVE_VSNPRINTF | |
1215 | written = vsnprintf(buffer, ST_VPRINTF_SIZE, format, ap); | |
1216 | #else | |
0e80ec22 | 1217 | written = vsprintf(buffer, format, ap); |
1218 | ||
1219 | if (written >= ST_VPRINTF_SIZE-1) | |
1220 | { | |
1221 | /* The error message was longer than our buffer. Ouch. Because | |
1222 | we may have messed up things badly, report the error and | |
1223 | quit. */ | |
1224 | #define ERROR_MESSAGE "Internal error: buffer overrun in st_vprintf()\n" | |
1225 | write (fd, buffer, ST_VPRINTF_SIZE-1); | |
1226 | write (fd, ERROR_MESSAGE, strlen(ERROR_MESSAGE)); | |
1227 | sys_exit(2); | |
1228 | #undef ERROR_MESSAGE | |
1229 | ||
1230 | } | |
5a037dbd | 1231 | #endif |
0e80ec22 | 1232 | |
5a037dbd | 1233 | written = write (fd, buffer, written); |
1234 | return written; | |
4ee9c684 | 1235 | } |
1236 | ||
5a037dbd | 1237 | /* st_printf()-- printf() function for error output. This just calls |
1238 | st_vprintf() to do the actual work. */ | |
76c0a846 | 1239 | |
1240 | int | |
1241 | st_printf (const char *format, ...) | |
1242 | { | |
5a037dbd | 1243 | int written; |
1244 | va_list ap; | |
1245 | va_start (ap, format); | |
1246 | written = st_vprintf(format, ap); | |
1247 | va_end (ap); | |
1248 | return written; | |
76c0a846 | 1249 | } |
1250 | ||
4ee9c684 | 1251 | |
1252 | /* compare_file_filename()-- Given an open stream and a fortran string | |
1253 | * that is a filename, figure out if the file is the same as the | |
1254 | * filename. */ | |
1255 | ||
1256 | int | |
daad4fd5 | 1257 | compare_file_filename (gfc_unit *u, const char *name, int len) |
4ee9c684 | 1258 | { |
1259 | char path[PATH_MAX + 1]; | |
7a4491a4 | 1260 | gfstat_t st1; |
daad4fd5 | 1261 | #ifdef HAVE_WORKING_STAT |
7a4491a4 | 1262 | gfstat_t st2; |
c0ecd33c | 1263 | #else |
1264 | # ifdef __MINGW32__ | |
1265 | uint64_t id1, id2; | |
1266 | # endif | |
daad4fd5 | 1267 | #endif |
4ee9c684 | 1268 | |
1269 | if (unpack_filename (path, name, len)) | |
1270 | return 0; /* Can't be the same */ | |
1271 | ||
1272 | /* If the filename doesn't exist, then there is no match with the | |
1273 | * existing file. */ | |
1274 | ||
1275 | if (stat (path, &st1) < 0) | |
1276 | return 0; | |
1277 | ||
daad4fd5 | 1278 | #ifdef HAVE_WORKING_STAT |
1279 | fstat (((unix_stream *) (u->s))->fd, &st2); | |
4ee9c684 | 1280 | return (st1.st_dev == st2.st_dev) && (st1.st_ino == st2.st_ino); |
daad4fd5 | 1281 | #else |
c0ecd33c | 1282 | |
1283 | # ifdef __MINGW32__ | |
1284 | /* We try to match files by a unique ID. On some filesystems (network | |
1285 | fs and FAT), we can't generate this unique ID, and will simply compare | |
1286 | filenames. */ | |
1287 | id1 = id_from_path (path); | |
1288 | id2 = id_from_fd (((unix_stream *) (u->s))->fd); | |
1289 | if (id1 || id2) | |
1290 | return (id1 == id2); | |
1291 | # endif | |
1292 | ||
daad4fd5 | 1293 | if (len != u->file_len) |
1294 | return 0; | |
1295 | return (memcmp(path, u->file, len) == 0); | |
1296 | #endif | |
4ee9c684 | 1297 | } |
1298 | ||
1299 | ||
60c514ba | 1300 | #ifdef HAVE_WORKING_STAT |
7a4491a4 | 1301 | # define FIND_FILE0_DECL gfstat_t *st |
60c514ba | 1302 | # define FIND_FILE0_ARGS st |
1303 | #else | |
c0ecd33c | 1304 | # define FIND_FILE0_DECL uint64_t id, const char *file, gfc_charlen_type file_len |
1305 | # define FIND_FILE0_ARGS id, file, file_len | |
60c514ba | 1306 | #endif |
1307 | ||
4ee9c684 | 1308 | /* find_file0()-- Recursive work function for find_file() */ |
1309 | ||
f02dd226 | 1310 | static gfc_unit * |
60c514ba | 1311 | find_file0 (gfc_unit *u, FIND_FILE0_DECL) |
4ee9c684 | 1312 | { |
f02dd226 | 1313 | gfc_unit *v; |
c0ecd33c | 1314 | #if defined(__MINGW32__) && !HAVE_WORKING_STAT |
1315 | uint64_t id1; | |
1316 | #endif | |
4ee9c684 | 1317 | |
1318 | if (u == NULL) | |
1319 | return NULL; | |
1320 | ||
daad4fd5 | 1321 | #ifdef HAVE_WORKING_STAT |
60c514ba | 1322 | if (u->s != NULL |
1323 | && fstat (((unix_stream *) u->s)->fd, &st[1]) >= 0 && | |
1324 | st[0].st_dev == st[1].st_dev && st[0].st_ino == st[1].st_ino) | |
4ee9c684 | 1325 | return u; |
daad4fd5 | 1326 | #else |
c0ecd33c | 1327 | # ifdef __MINGW32__ |
1328 | if (u->s && ((id1 = id_from_fd (((unix_stream *) u->s)->fd)) || id1)) | |
1329 | { | |
1330 | if (id == id1) | |
1331 | return u; | |
1332 | } | |
1333 | else | |
1334 | # endif | |
1335 | if (compare_string (u->file_len, u->file, file_len, file) == 0) | |
1336 | return u; | |
daad4fd5 | 1337 | #endif |
4ee9c684 | 1338 | |
60c514ba | 1339 | v = find_file0 (u->left, FIND_FILE0_ARGS); |
4ee9c684 | 1340 | if (v != NULL) |
1341 | return v; | |
1342 | ||
60c514ba | 1343 | v = find_file0 (u->right, FIND_FILE0_ARGS); |
4ee9c684 | 1344 | if (v != NULL) |
1345 | return v; | |
1346 | ||
1347 | return NULL; | |
1348 | } | |
1349 | ||
1350 | ||
1351 | /* find_file()-- Take the current filename and see if there is a unit | |
1352 | * that has the file already open. Returns a pointer to the unit if so. */ | |
1353 | ||
f02dd226 | 1354 | gfc_unit * |
60c514ba | 1355 | find_file (const char *file, gfc_charlen_type file_len) |
4ee9c684 | 1356 | { |
1357 | char path[PATH_MAX + 1]; | |
7a4491a4 | 1358 | gfstat_t st[2]; |
60c514ba | 1359 | gfc_unit *u; |
c12dc7d7 | 1360 | #if defined(__MINGW32__) && !HAVE_WORKING_STAT |
1361 | uint64_t id = 0ULL; | |
1362 | #endif | |
4ee9c684 | 1363 | |
60c514ba | 1364 | if (unpack_filename (path, file, file_len)) |
4ee9c684 | 1365 | return NULL; |
1366 | ||
60c514ba | 1367 | if (stat (path, &st[0]) < 0) |
4ee9c684 | 1368 | return NULL; |
1369 | ||
c0ecd33c | 1370 | #if defined(__MINGW32__) && !HAVE_WORKING_STAT |
c12dc7d7 | 1371 | id = id_from_path (path); |
c0ecd33c | 1372 | #endif |
1373 | ||
60c514ba | 1374 | __gthread_mutex_lock (&unit_lock); |
1375 | retry: | |
1376 | u = find_file0 (unit_root, FIND_FILE0_ARGS); | |
1377 | if (u != NULL) | |
1378 | { | |
1379 | /* Fast path. */ | |
1380 | if (! __gthread_mutex_trylock (&u->lock)) | |
1381 | { | |
1382 | /* assert (u->closed == 0); */ | |
1383 | __gthread_mutex_unlock (&unit_lock); | |
1384 | return u; | |
1385 | } | |
1386 | ||
1387 | inc_waiting_locked (u); | |
1388 | } | |
1389 | __gthread_mutex_unlock (&unit_lock); | |
1390 | if (u != NULL) | |
1391 | { | |
1392 | __gthread_mutex_lock (&u->lock); | |
1393 | if (u->closed) | |
1394 | { | |
1395 | __gthread_mutex_lock (&unit_lock); | |
1396 | __gthread_mutex_unlock (&u->lock); | |
1397 | if (predec_waiting_locked (u) == 0) | |
1398 | free_mem (u); | |
1399 | goto retry; | |
1400 | } | |
1401 | ||
1402 | dec_waiting_unlocked (u); | |
1403 | } | |
1404 | return u; | |
1405 | } | |
1406 | ||
1407 | static gfc_unit * | |
1408 | flush_all_units_1 (gfc_unit *u, int min_unit) | |
1409 | { | |
1410 | while (u != NULL) | |
1411 | { | |
1412 | if (u->unit_number > min_unit) | |
1413 | { | |
1414 | gfc_unit *r = flush_all_units_1 (u->left, min_unit); | |
1415 | if (r != NULL) | |
1416 | return r; | |
1417 | } | |
1418 | if (u->unit_number >= min_unit) | |
1419 | { | |
1420 | if (__gthread_mutex_trylock (&u->lock)) | |
1421 | return u; | |
1422 | if (u->s) | |
65f15010 | 1423 | sflush (u->s); |
60c514ba | 1424 | __gthread_mutex_unlock (&u->lock); |
1425 | } | |
1426 | u = u->right; | |
1427 | } | |
1428 | return NULL; | |
1429 | } | |
1430 | ||
1431 | void | |
1432 | flush_all_units (void) | |
1433 | { | |
1434 | gfc_unit *u; | |
1435 | int min_unit = 0; | |
1436 | ||
1437 | __gthread_mutex_lock (&unit_lock); | |
1438 | do | |
1439 | { | |
1440 | u = flush_all_units_1 (unit_root, min_unit); | |
1441 | if (u != NULL) | |
1442 | inc_waiting_locked (u); | |
1443 | __gthread_mutex_unlock (&unit_lock); | |
1444 | if (u == NULL) | |
1445 | return; | |
1446 | ||
1447 | __gthread_mutex_lock (&u->lock); | |
1448 | ||
1449 | min_unit = u->unit_number + 1; | |
1450 | ||
1451 | if (u->closed == 0) | |
1452 | { | |
65f15010 | 1453 | sflush (u->s); |
60c514ba | 1454 | __gthread_mutex_lock (&unit_lock); |
1455 | __gthread_mutex_unlock (&u->lock); | |
1456 | (void) predec_waiting_locked (u); | |
1457 | } | |
1458 | else | |
1459 | { | |
1460 | __gthread_mutex_lock (&unit_lock); | |
1461 | __gthread_mutex_unlock (&u->lock); | |
1462 | if (predec_waiting_locked (u) == 0) | |
1463 | free_mem (u); | |
1464 | } | |
1465 | } | |
1466 | while (1); | |
4ee9c684 | 1467 | } |
1468 | ||
1469 | ||
4ee9c684 | 1470 | /* delete_file()-- Given a unit structure, delete the file associated |
1471 | * with the unit. Returns nonzero if something went wrong. */ | |
1472 | ||
1473 | int | |
f02dd226 | 1474 | delete_file (gfc_unit * u) |
4ee9c684 | 1475 | { |
1476 | char path[PATH_MAX + 1]; | |
1477 | ||
1478 | if (unpack_filename (path, u->file, u->file_len)) | |
1479 | { /* Shouldn't be possible */ | |
1480 | errno = ENOENT; | |
1481 | return 1; | |
1482 | } | |
1483 | ||
1484 | return unlink (path); | |
1485 | } | |
1486 | ||
1487 | ||
1488 | /* file_exists()-- Returns nonzero if the current filename exists on | |
1489 | * the system */ | |
1490 | ||
1491 | int | |
60c514ba | 1492 | file_exists (const char *file, gfc_charlen_type file_len) |
4ee9c684 | 1493 | { |
1494 | char path[PATH_MAX + 1]; | |
7a4491a4 | 1495 | gfstat_t statbuf; |
4ee9c684 | 1496 | |
60c514ba | 1497 | if (unpack_filename (path, file, file_len)) |
4ee9c684 | 1498 | return 0; |
1499 | ||
1500 | if (stat (path, &statbuf) < 0) | |
1501 | return 0; | |
1502 | ||
1503 | return 1; | |
1504 | } | |
1505 | ||
1506 | ||
f4e9c676 | 1507 | /* file_size()-- Returns the size of the file. */ |
1508 | ||
1509 | GFC_IO_INT | |
1510 | file_size (const char *file, gfc_charlen_type file_len) | |
1511 | { | |
1512 | char path[PATH_MAX + 1]; | |
1513 | gfstat_t statbuf; | |
1514 | ||
1515 | if (unpack_filename (path, file, file_len)) | |
1516 | return -1; | |
1517 | ||
1518 | if (stat (path, &statbuf) < 0) | |
1519 | return -1; | |
1520 | ||
1521 | return (GFC_IO_INT) statbuf.st_size; | |
1522 | } | |
4ee9c684 | 1523 | |
fb35179a | 1524 | static const char yes[] = "YES", no[] = "NO", unknown[] = "UNKNOWN"; |
4ee9c684 | 1525 | |
1526 | /* inquire_sequential()-- Given a fortran string, determine if the | |
1527 | * file is suitable for sequential access. Returns a C-style | |
1528 | * string. */ | |
1529 | ||
1530 | const char * | |
1531 | inquire_sequential (const char *string, int len) | |
1532 | { | |
1533 | char path[PATH_MAX + 1]; | |
7a4491a4 | 1534 | gfstat_t statbuf; |
4ee9c684 | 1535 | |
1536 | if (string == NULL || | |
1537 | unpack_filename (path, string, len) || stat (path, &statbuf) < 0) | |
1538 | return unknown; | |
1539 | ||
1540 | if (S_ISREG (statbuf.st_mode) || | |
1541 | S_ISCHR (statbuf.st_mode) || S_ISFIFO (statbuf.st_mode)) | |
2e1fa727 | 1542 | return unknown; |
4ee9c684 | 1543 | |
1544 | if (S_ISDIR (statbuf.st_mode) || S_ISBLK (statbuf.st_mode)) | |
1545 | return no; | |
1546 | ||
1547 | return unknown; | |
1548 | } | |
1549 | ||
1550 | ||
1551 | /* inquire_direct()-- Given a fortran string, determine if the file is | |
1552 | * suitable for direct access. Returns a C-style string. */ | |
1553 | ||
1554 | const char * | |
1555 | inquire_direct (const char *string, int len) | |
1556 | { | |
1557 | char path[PATH_MAX + 1]; | |
7a4491a4 | 1558 | gfstat_t statbuf; |
4ee9c684 | 1559 | |
1560 | if (string == NULL || | |
1561 | unpack_filename (path, string, len) || stat (path, &statbuf) < 0) | |
1562 | return unknown; | |
1563 | ||
1564 | if (S_ISREG (statbuf.st_mode) || S_ISBLK (statbuf.st_mode)) | |
2e1fa727 | 1565 | return unknown; |
4ee9c684 | 1566 | |
1567 | if (S_ISDIR (statbuf.st_mode) || | |
1568 | S_ISCHR (statbuf.st_mode) || S_ISFIFO (statbuf.st_mode)) | |
1569 | return no; | |
1570 | ||
1571 | return unknown; | |
1572 | } | |
1573 | ||
1574 | ||
1575 | /* inquire_formatted()-- Given a fortran string, determine if the file | |
1576 | * is suitable for formatted form. Returns a C-style string. */ | |
1577 | ||
1578 | const char * | |
1579 | inquire_formatted (const char *string, int len) | |
1580 | { | |
1581 | char path[PATH_MAX + 1]; | |
7a4491a4 | 1582 | gfstat_t statbuf; |
4ee9c684 | 1583 | |
1584 | if (string == NULL || | |
1585 | unpack_filename (path, string, len) || stat (path, &statbuf) < 0) | |
1586 | return unknown; | |
1587 | ||
1588 | if (S_ISREG (statbuf.st_mode) || | |
1589 | S_ISBLK (statbuf.st_mode) || | |
1590 | S_ISCHR (statbuf.st_mode) || S_ISFIFO (statbuf.st_mode)) | |
2e1fa727 | 1591 | return unknown; |
4ee9c684 | 1592 | |
1593 | if (S_ISDIR (statbuf.st_mode)) | |
1594 | return no; | |
1595 | ||
1596 | return unknown; | |
1597 | } | |
1598 | ||
1599 | ||
1600 | /* inquire_unformatted()-- Given a fortran string, determine if the file | |
1601 | * is suitable for unformatted form. Returns a C-style string. */ | |
1602 | ||
1603 | const char * | |
1604 | inquire_unformatted (const char *string, int len) | |
1605 | { | |
4ee9c684 | 1606 | return inquire_formatted (string, len); |
1607 | } | |
1608 | ||
1609 | ||
e0582811 | 1610 | #ifndef HAVE_ACCESS |
1611 | ||
1612 | #ifndef W_OK | |
1613 | #define W_OK 2 | |
1614 | #endif | |
1615 | ||
1616 | #ifndef R_OK | |
1617 | #define R_OK 4 | |
1618 | #endif | |
1619 | ||
1620 | /* Fallback implementation of access() on systems that don't have it. | |
1621 | Only modes R_OK and W_OK are used in this file. */ | |
1622 | ||
1623 | static int | |
1624 | fallback_access (const char *path, int mode) | |
1625 | { | |
1626 | if ((mode & R_OK) && open (path, O_RDONLY) < 0) | |
1627 | return -1; | |
1628 | ||
1629 | if ((mode & W_OK) && open (path, O_WRONLY) < 0) | |
1630 | return -1; | |
1631 | ||
1632 | return 0; | |
1633 | } | |
1634 | ||
1635 | #undef access | |
1636 | #define access fallback_access | |
1637 | #endif | |
1638 | ||
1639 | ||
4ee9c684 | 1640 | /* inquire_access()-- Given a fortran string, determine if the file is |
1641 | * suitable for access. */ | |
1642 | ||
1643 | static const char * | |
1644 | inquire_access (const char *string, int len, int mode) | |
1645 | { | |
1646 | char path[PATH_MAX + 1]; | |
1647 | ||
1648 | if (string == NULL || unpack_filename (path, string, len) || | |
1649 | access (path, mode) < 0) | |
1650 | return no; | |
1651 | ||
1652 | return yes; | |
1653 | } | |
1654 | ||
1655 | ||
1656 | /* inquire_read()-- Given a fortran string, determine if the file is | |
1657 | * suitable for READ access. */ | |
1658 | ||
1659 | const char * | |
1660 | inquire_read (const char *string, int len) | |
1661 | { | |
4ee9c684 | 1662 | return inquire_access (string, len, R_OK); |
1663 | } | |
1664 | ||
1665 | ||
1666 | /* inquire_write()-- Given a fortran string, determine if the file is | |
1667 | * suitable for READ access. */ | |
1668 | ||
1669 | const char * | |
1670 | inquire_write (const char *string, int len) | |
1671 | { | |
4ee9c684 | 1672 | return inquire_access (string, len, W_OK); |
1673 | } | |
1674 | ||
1675 | ||
1676 | /* inquire_readwrite()-- Given a fortran string, determine if the file is | |
1677 | * suitable for read and write access. */ | |
1678 | ||
1679 | const char * | |
1680 | inquire_readwrite (const char *string, int len) | |
1681 | { | |
4ee9c684 | 1682 | return inquire_access (string, len, R_OK | W_OK); |
1683 | } | |
1684 | ||
1685 | ||
1686 | /* file_length()-- Return the file length in bytes, -1 if unknown */ | |
1687 | ||
b093181d | 1688 | gfc_offset |
4ee9c684 | 1689 | file_length (stream * s) |
1690 | { | |
4dbc0658 | 1691 | gfc_offset curr, end; |
65f15010 | 1692 | if (!is_seekable (s)) |
1693 | return -1; | |
1694 | curr = stell (s); | |
1695 | if (curr == -1) | |
1696 | return curr; | |
1697 | end = sseek (s, 0, SEEK_END); | |
1698 | sseek (s, curr, SEEK_SET); | |
1699 | return end; | |
4ee9c684 | 1700 | } |
1701 | ||
1702 | ||
1703 | /* is_seekable()-- Return nonzero if the stream is seekable, zero if | |
1704 | * it is not */ | |
1705 | ||
1706 | int | |
6e34b5c4 | 1707 | is_seekable (stream *s) |
4ee9c684 | 1708 | { |
b2a112ca | 1709 | /* By convention, if file_length == -1, the file is not |
1710 | seekable. */ | |
5a78b88f | 1711 | return ((unix_stream *) s)->file_length!=-1; |
4ee9c684 | 1712 | } |
1713 | ||
6e34b5c4 | 1714 | |
1715 | /* is_special()-- Return nonzero if the stream is not a regular file. */ | |
1716 | ||
09478184 | 1717 | int |
6e34b5c4 | 1718 | is_special (stream *s) |
1719 | { | |
1720 | return ((unix_stream *) s)->special_file; | |
1721 | } | |
1722 | ||
1723 | ||
60d77e0d | 1724 | int |
1725 | stream_isatty (stream *s) | |
1726 | { | |
1727 | return isatty (((unix_stream *) s)->fd); | |
1728 | } | |
1729 | ||
1730 | char * | |
7b3e325b | 1731 | stream_ttyname (stream *s __attribute__ ((unused))) |
60d77e0d | 1732 | { |
f2c0a16d | 1733 | #ifdef HAVE_TTYNAME |
60d77e0d | 1734 | return ttyname (((unix_stream *) s)->fd); |
f2c0a16d | 1735 | #else |
1736 | return NULL; | |
1737 | #endif | |
60d77e0d | 1738 | } |
1739 | ||
4ee9c684 | 1740 | |
1741 | /* How files are stored: This is an operating-system specific issue, | |
1742 | and therefore belongs here. There are three cases to consider. | |
1743 | ||
1744 | Direct Access: | |
1745 | Records are written as block of bytes corresponding to the record | |
1746 | length of the file. This goes for both formatted and unformatted | |
1747 | records. Positioning is done explicitly for each data transfer, | |
1748 | so positioning is not much of an issue. | |
1749 | ||
1750 | Sequential Formatted: | |
1751 | Records are separated by newline characters. The newline character | |
1752 | is prohibited from appearing in a string. If it does, this will be | |
1753 | messed up on the next read. End of file is also the end of a record. | |
1754 | ||
1755 | Sequential Unformatted: | |
1756 | In this case, we are merely copying bytes to and from main storage, | |
1757 | yet we need to keep track of varying record lengths. We adopt | |
1758 | the solution used by f2c. Each record contains a pair of length | |
1759 | markers: | |
1760 | ||
84d33b91 | 1761 | Length of record n in bytes |
1762 | Data of record n | |
1763 | Length of record n in bytes | |
4ee9c684 | 1764 | |
84d33b91 | 1765 | Length of record n+1 in bytes |
1766 | Data of record n+1 | |
1767 | Length of record n+1 in bytes | |
4ee9c684 | 1768 | |
1769 | The length is stored at the end of a record to allow backspacing to the | |
1770 | previous record. Between data transfer statements, the file pointer | |
1771 | is left pointing to the first length of the current record. | |
1772 | ||
1773 | ENDFILE records are never explicitly stored. | |
1774 | ||
1775 | */ |