1 | @c |
---|
2 | @c COPYRIGHT (c) 1988-1999. |
---|
3 | @c On-Line Applications Research Corporation (OAR). |
---|
4 | @c All rights reserved. |
---|
5 | @c |
---|
6 | @c $Id$ |
---|
7 | @c |
---|
8 | |
---|
9 | @chapter Files and Directories Manager |
---|
10 | |
---|
11 | @section Introduction |
---|
12 | |
---|
13 | The files and directories manager is ... |
---|
14 | |
---|
15 | The directives provided by the files and directories manager are: |
---|
16 | |
---|
17 | @itemize @bullet |
---|
18 | @item @code{opendir} - Open a Directory |
---|
19 | @item @code{readdir} - Reads a directory |
---|
20 | @item @code{rewinddir} - Resets the @code{readdir()} pointer |
---|
21 | @item @code{scandir} - Scan a directory for matching entries |
---|
22 | @item @code{telldir} - Return current location in directory stream |
---|
23 | @item @code{closedir} - Ends directory read operation |
---|
24 | @item @code{getdents} - Get directory entries |
---|
25 | @item @code{chdir} - Changes the current working directory |
---|
26 | @item @code{getcwd} - Gets current working directory |
---|
27 | @item @code{open} - Opens a file |
---|
28 | @item @code{creat} - Create a new file or rewrite an existing one |
---|
29 | @item @code{umask} - Sets a file creation mask |
---|
30 | @item @code{link} - Creates a link to a file |
---|
31 | @item @code{symlink} - Creates a symbolic link to a file |
---|
32 | @item @code{readlink} - Obtain the name of the link destination |
---|
33 | @item @code{mkdir} - Makes a directory |
---|
34 | @item @code{mkfifo} - Makes a FIFO special file |
---|
35 | @item @code{unlink} - Removes a directory entry |
---|
36 | @item @code{rmdir} - Delete a directory |
---|
37 | @item @code{rename} - Renames a file |
---|
38 | @item @code{stat} - Gets information about a file. |
---|
39 | @item @code{fstat} - Gets file status |
---|
40 | @item @code{lstat} - Gets file status |
---|
41 | @item @code{access} - Check permissions for a file. |
---|
42 | @item @code{chmod} - Changes file mode |
---|
43 | @item @code{fchmod} - Changes permissions of a file |
---|
44 | @item @code{chown} - Changes the owner and/ or group of a file |
---|
45 | @item @code{utime} - Change access and/or modification times of an inode |
---|
46 | @item @code{ftruncate} - Truncate a file to a specified length |
---|
47 | @item @code{truncate} - Truncate a file to a specified length |
---|
48 | @item @code{pathconf} - Gets configuration values for files |
---|
49 | @item @code{fpathconf} - Get configuration values for files |
---|
50 | @item @code{mknod} - Create a directory |
---|
51 | @end itemize |
---|
52 | |
---|
53 | @section Background |
---|
54 | |
---|
55 | @subsection Path Name Evaluation |
---|
56 | |
---|
57 | A pathname is a string that consists of no more than @code{PATH_MAX} |
---|
58 | bytes, including the terminating null character. A pathname has an optional |
---|
59 | beginning slash, followed by zero or more filenames separated by slashes. |
---|
60 | If the pathname refers to a directory, it may also have one or more trailing |
---|
61 | slashes. Multiple successive slahes are considered to be the same as |
---|
62 | one slash. |
---|
63 | |
---|
64 | POSIX allows a pathname that begins with precisely two successive slashes to be |
---|
65 | interpreted in an implementation-defined manner. RTEMS does not currently |
---|
66 | recognize this as a special condition. Any number of successive |
---|
67 | slashes is treated the same as a single slash. POSIX requires that |
---|
68 | an implementation treat more than two leading slashes as a single slash. |
---|
69 | |
---|
70 | @section Operations |
---|
71 | |
---|
72 | There is currently no text in this section. |
---|
73 | |
---|
74 | @section Directives |
---|
75 | |
---|
76 | This section details the files and directories manager's directives. |
---|
77 | A subsection is dedicated to each of this manager's directives |
---|
78 | and describes the calling sequence, related constants, usage, |
---|
79 | and status codes. |
---|
80 | |
---|
81 | @c |
---|
82 | @c |
---|
83 | @c |
---|
84 | @page |
---|
85 | @subsection opendir - Open a Directory |
---|
86 | |
---|
87 | @findex opendir |
---|
88 | @cindex open a directory |
---|
89 | |
---|
90 | @subheading CALLING SEQUENCE: |
---|
91 | |
---|
92 | @ifset is-C |
---|
93 | @example |
---|
94 | #include <sys/types.h> |
---|
95 | #include <dirent.h> |
---|
96 | |
---|
97 | int opendir( |
---|
98 | const char *dirname |
---|
99 | ); |
---|
100 | @end example |
---|
101 | @end ifset |
---|
102 | |
---|
103 | @ifset is-Ada |
---|
104 | @end ifset |
---|
105 | |
---|
106 | @subheading STATUS CODES: |
---|
107 | |
---|
108 | @table @b |
---|
109 | @item EACCES |
---|
110 | Search permission was denied on a component of the path |
---|
111 | prefix of @code{dirname}, or read permission is denied |
---|
112 | |
---|
113 | @item EMFILE |
---|
114 | Too many file descriptors in use by process |
---|
115 | |
---|
116 | @item ENFILE |
---|
117 | Too many files are currently open in the system. |
---|
118 | |
---|
119 | @item ENOENT |
---|
120 | Directory does not exist, or @code{name} is an empty string. |
---|
121 | |
---|
122 | @item ENOMEM |
---|
123 | Insufficient memory to complete the operation. |
---|
124 | |
---|
125 | @item ENOTDIR |
---|
126 | @code{name} is not a directory. |
---|
127 | |
---|
128 | @end table |
---|
129 | |
---|
130 | @subheading DESCRIPTION: |
---|
131 | |
---|
132 | This routine opens a directory stream corresponding to the |
---|
133 | directory specified by the @code{dirname} argument. The |
---|
134 | directory stream is positioned at the first entry. |
---|
135 | |
---|
136 | @subheading NOTES: |
---|
137 | |
---|
138 | The routine is implemented in Cygnus newlib. |
---|
139 | |
---|
140 | @c |
---|
141 | @c |
---|
142 | @c |
---|
143 | @page |
---|
144 | @subsection readdir - Reads a directory |
---|
145 | |
---|
146 | @findex readdir |
---|
147 | @cindex reads a directory |
---|
148 | |
---|
149 | @subheading CALLING SEQUENCE: |
---|
150 | |
---|
151 | @ifset is-C |
---|
152 | @example |
---|
153 | #include <sys/types.h> |
---|
154 | #include <dirent.h> |
---|
155 | |
---|
156 | int readdir( |
---|
157 | DIR *dirp |
---|
158 | ); |
---|
159 | @end example |
---|
160 | @end ifset |
---|
161 | |
---|
162 | @ifset is-Ada |
---|
163 | @end ifset |
---|
164 | |
---|
165 | @subheading STATUS CODES: |
---|
166 | |
---|
167 | @table @b |
---|
168 | @item EBADF |
---|
169 | Invalid file descriptor |
---|
170 | |
---|
171 | @end table |
---|
172 | |
---|
173 | @subheading DESCRIPTION: |
---|
174 | |
---|
175 | The @code{readdir()} function returns a pointer to a structure @code{dirent} |
---|
176 | representing the next directory entry from the directory stream pointed to |
---|
177 | by @code{dirp}. On end-of-file, NULL is returned. |
---|
178 | |
---|
179 | The @code{readdir()} function may (or may not) return entries for . or .. Your |
---|
180 | program should tolerate reading dot and dot-dot but not require them. |
---|
181 | |
---|
182 | The data pointed to be @code{readdir()} may be overwritten by another call to |
---|
183 | @code{readdir()} for the same directory stream. It will not be overwritten by |
---|
184 | a call for another directory. |
---|
185 | |
---|
186 | @subheading NOTES: |
---|
187 | |
---|
188 | If @code{ptr} is not a pointer returned by @code{malloc()}, @code{calloc()}, or |
---|
189 | @code{realloc()} or has been deallocated with @code{free()} or |
---|
190 | @code{realloc()}, the results are not portable and are probably disastrous. |
---|
191 | |
---|
192 | The routine is implemented in Cygnus newlib. |
---|
193 | |
---|
194 | @c |
---|
195 | @c |
---|
196 | @c |
---|
197 | @page |
---|
198 | @subsection rewinddir - Resets the readdir() pointer |
---|
199 | |
---|
200 | @findex rewinddir |
---|
201 | @cindex resets the readdir() pointer |
---|
202 | |
---|
203 | @subheading CALLING SEQUENCE: |
---|
204 | |
---|
205 | @ifset is-C |
---|
206 | @example |
---|
207 | #include <sys/types.h> |
---|
208 | #include <dirent.h> |
---|
209 | |
---|
210 | void rewinddir( |
---|
211 | DIR *dirp |
---|
212 | ); |
---|
213 | @end example |
---|
214 | @end ifset |
---|
215 | |
---|
216 | @ifset is-Ada |
---|
217 | @end ifset |
---|
218 | |
---|
219 | @subheading STATUS CODES: |
---|
220 | |
---|
221 | No value is returned. |
---|
222 | |
---|
223 | @subheading DESCRIPTION: |
---|
224 | |
---|
225 | The @code{rewinddir()} function resets the position associated with |
---|
226 | the directory stream pointed to by @code{dirp}. It also causes the |
---|
227 | directory stream to refer to the current state of the directory. |
---|
228 | |
---|
229 | @subheading NOTES: |
---|
230 | |
---|
231 | NONE |
---|
232 | |
---|
233 | If @code{dirp} is not a pointer by @code{opendir()}, the results are |
---|
234 | undefined. |
---|
235 | |
---|
236 | The routine is implemented in Cygnus newlib. |
---|
237 | |
---|
238 | @c |
---|
239 | @c |
---|
240 | @c |
---|
241 | @page |
---|
242 | @subsection scandir - Scan a directory for matching entries |
---|
243 | |
---|
244 | @findex scandir |
---|
245 | @cindex scan a directory for matching entries |
---|
246 | |
---|
247 | @subheading CALLING SEQUENCE: |
---|
248 | |
---|
249 | @ifset is-C |
---|
250 | @example |
---|
251 | #include <dirent.h> |
---|
252 | |
---|
253 | int scandir( |
---|
254 | const char *dir, |
---|
255 | struct dirent ***namelist, |
---|
256 | int (*select)(const struct dirent *), |
---|
257 | int (*compar)(const struct dirent **, const struct dirent **) |
---|
258 | ); |
---|
259 | @end example |
---|
260 | @end ifset |
---|
261 | |
---|
262 | @ifset is-Ada |
---|
263 | @end ifset |
---|
264 | |
---|
265 | @subheading STATUS CODES: |
---|
266 | |
---|
267 | @table @b |
---|
268 | @item ENOMEM |
---|
269 | Insufficient memory to complete the operation. |
---|
270 | |
---|
271 | @end table |
---|
272 | |
---|
273 | @subheading DESCRIPTION: |
---|
274 | |
---|
275 | The @code{scandir()} function scans the directory @code{dir}, calling |
---|
276 | @code{select()} on each directory entry. Entries for which @code{select()} |
---|
277 | returns non-zero are stored in strings allocated via @code{malloc()}, |
---|
278 | sorted using @code{qsort()} with the comparison function @code{compar()}, |
---|
279 | and collected in array @code{namelist} which is allocated via @code{malloc()}. |
---|
280 | If @code{select} is NULL, all entries are selected. |
---|
281 | |
---|
282 | @subheading NOTES: |
---|
283 | |
---|
284 | The routine is implemented in Cygnus newlib. |
---|
285 | |
---|
286 | @c |
---|
287 | @c |
---|
288 | @c |
---|
289 | @page |
---|
290 | @subsection telldir - Return current location in directory stream |
---|
291 | |
---|
292 | @findex telldir |
---|
293 | @cindex return current location in directory stream |
---|
294 | |
---|
295 | @subheading CALLING SEQUENCE: |
---|
296 | |
---|
297 | @ifset is-C |
---|
298 | @example |
---|
299 | #include <dirent.h> |
---|
300 | |
---|
301 | off_t telldir( |
---|
302 | DIR *dir |
---|
303 | ); |
---|
304 | @end example |
---|
305 | @end ifset |
---|
306 | |
---|
307 | @ifset is-Ada |
---|
308 | @end ifset |
---|
309 | |
---|
310 | @subheading STATUS CODES: |
---|
311 | |
---|
312 | @table @b |
---|
313 | @item EBADF |
---|
314 | Invalid directory stream descriptor @code{dir}. |
---|
315 | |
---|
316 | @end table |
---|
317 | |
---|
318 | @subheading DESCRIPTION: |
---|
319 | |
---|
320 | The @code{telldir()} function returns the current location associated with the |
---|
321 | directory stream @code{dir}. |
---|
322 | |
---|
323 | @subheading NOTES: |
---|
324 | |
---|
325 | The routine is implemented in Cygnus newlib. |
---|
326 | |
---|
327 | @c |
---|
328 | @c |
---|
329 | @c |
---|
330 | @page |
---|
331 | @subsection closedir - Ends directory read operation |
---|
332 | |
---|
333 | @findex closedir |
---|
334 | @cindex ends directory read operation |
---|
335 | |
---|
336 | @subheading CALLING SEQUENCE: |
---|
337 | |
---|
338 | @ifset is-C |
---|
339 | @example |
---|
340 | #include <sys/types.h> |
---|
341 | #include <dirent.h> |
---|
342 | |
---|
343 | int closedir( |
---|
344 | DIR *dirp |
---|
345 | ); |
---|
346 | @end example |
---|
347 | @end ifset |
---|
348 | |
---|
349 | @ifset is-Ada |
---|
350 | @end ifset |
---|
351 | |
---|
352 | @subheading STATUS CODES: |
---|
353 | |
---|
354 | @table @b |
---|
355 | @item EBADF |
---|
356 | Invalid file descriptor |
---|
357 | |
---|
358 | @end table |
---|
359 | |
---|
360 | @subheading DESCRIPTION: |
---|
361 | |
---|
362 | The directory stream associated with @code{dirp} is closed. |
---|
363 | The value in @code{dirp} may not be usable after a call to |
---|
364 | @code{closedir()}. |
---|
365 | |
---|
366 | @subheading NOTES: |
---|
367 | |
---|
368 | NONE |
---|
369 | |
---|
370 | The argument to @code{closedir()} must be a pointer returned by |
---|
371 | @code{opendir()}. If it is not, the results are not portable and |
---|
372 | most likely unpleasant. |
---|
373 | |
---|
374 | The routine is implemented in Cygnus newlib. |
---|
375 | |
---|
376 | @c |
---|
377 | @c |
---|
378 | @c |
---|
379 | @page |
---|
380 | @subsection chdir - Changes the current working directory |
---|
381 | |
---|
382 | @findex chdir |
---|
383 | @cindex changes the current working directory |
---|
384 | |
---|
385 | @subheading CALLING SEQUENCE: |
---|
386 | |
---|
387 | @ifset is-C |
---|
388 | @example |
---|
389 | #include <unistd.h> |
---|
390 | |
---|
391 | int chdir( |
---|
392 | const char *path |
---|
393 | ); |
---|
394 | @end example |
---|
395 | @end ifset |
---|
396 | |
---|
397 | @ifset is-Ada |
---|
398 | @end ifset |
---|
399 | |
---|
400 | @subheading STATUS CODES: |
---|
401 | |
---|
402 | @table @b |
---|
403 | @item EACCES |
---|
404 | Search permission is denied for a directory in a file's path prefix. |
---|
405 | |
---|
406 | @item ENAMETOOLONG |
---|
407 | Length of a filename string exceeds PATH_MAX and _POSIX_NO_TRUNC is |
---|
408 | in effect. |
---|
409 | |
---|
410 | @item ENOENT |
---|
411 | A file or directory does not exist. |
---|
412 | |
---|
413 | @item ENOTDIR |
---|
414 | A component of the specified pathname was not a directory when directory |
---|
415 | was expected. |
---|
416 | |
---|
417 | @end table |
---|
418 | |
---|
419 | @subheading DESCRIPTION: |
---|
420 | |
---|
421 | The @code{chdir()} function causes the directory named by @code{path} to |
---|
422 | become the current working directory; that is, the starting point for |
---|
423 | searches of pathnames not beginning with a slash. |
---|
424 | |
---|
425 | If @code{chdir()} detects an error, the current working directory is not |
---|
426 | changed. |
---|
427 | |
---|
428 | @subheading NOTES: |
---|
429 | |
---|
430 | NONE |
---|
431 | |
---|
432 | @c |
---|
433 | @c |
---|
434 | @c |
---|
435 | @page |
---|
436 | @subsection getcwd - Gets current working directory |
---|
437 | |
---|
438 | @findex getcwd |
---|
439 | @cindex gets current working directory |
---|
440 | |
---|
441 | @subheading CALLING SEQUENCE: |
---|
442 | |
---|
443 | @ifset is-C |
---|
444 | @example |
---|
445 | #include <unistd.h> |
---|
446 | |
---|
447 | int getcwd( void ); |
---|
448 | @end example |
---|
449 | @end ifset |
---|
450 | |
---|
451 | @ifset is-Ada |
---|
452 | @end ifset |
---|
453 | |
---|
454 | @subheading STATUS CODES: |
---|
455 | |
---|
456 | @table @b |
---|
457 | @item EINVAL |
---|
458 | Invalid argument |
---|
459 | |
---|
460 | @item ERANGE |
---|
461 | Result is too large |
---|
462 | |
---|
463 | @item EACCES |
---|
464 | Search permission is denied for a directory in a file's path prefix. |
---|
465 | |
---|
466 | @end table |
---|
467 | |
---|
468 | @subheading DESCRIPTION: |
---|
469 | |
---|
470 | The @code{getcwd()} function copies the absolute pathname of the current |
---|
471 | working directory to the character array pointed to by @code{buf}. The |
---|
472 | @code{size} argument is the number of bytes available in @code{buf} |
---|
473 | |
---|
474 | @subheading NOTES: |
---|
475 | |
---|
476 | There is no way to determine the maximum string length that @code{fetcwd()} |
---|
477 | may need to return. Applications should tolerate getting @code{ERANGE} |
---|
478 | and allocate a larger buffer. |
---|
479 | |
---|
480 | It is possible for @code{getcwd()} to return EACCES if, say, @code{login} |
---|
481 | puts the process into a directory without read access. |
---|
482 | |
---|
483 | The 1988 standard uses @code{int} instead of @code{size_t} for the second |
---|
484 | parameter. |
---|
485 | |
---|
486 | @c |
---|
487 | @c |
---|
488 | @c |
---|
489 | @page |
---|
490 | @subsection open - Opens a file |
---|
491 | |
---|
492 | @findex open |
---|
493 | @cindex opens a file |
---|
494 | |
---|
495 | @subheading CALLING SEQUENCE: |
---|
496 | |
---|
497 | @ifset is-C |
---|
498 | @example |
---|
499 | #include <sys/types.h> |
---|
500 | #include <sys/stat.h> |
---|
501 | #include <fcntl.h> |
---|
502 | |
---|
503 | int open( |
---|
504 | const char *path, |
---|
505 | int oflag, |
---|
506 | mode_t mode |
---|
507 | ); |
---|
508 | @end example |
---|
509 | @end ifset |
---|
510 | |
---|
511 | @ifset is-Ada |
---|
512 | @end ifset |
---|
513 | |
---|
514 | @subheading STATUS CODES: |
---|
515 | |
---|
516 | @table @b |
---|
517 | |
---|
518 | @item EACCES |
---|
519 | Search permission is denied for a directory in a file's path prefix. |
---|
520 | |
---|
521 | @item EEXIST |
---|
522 | The named file already exists. |
---|
523 | |
---|
524 | @item EINTR |
---|
525 | Function was interrupted by a signal. |
---|
526 | |
---|
527 | @item EISDIR |
---|
528 | Attempt to open a directory for writing or to rename a file to be a |
---|
529 | directory. |
---|
530 | |
---|
531 | @item EMFILE |
---|
532 | Too many file descriptors are in use by this process. |
---|
533 | |
---|
534 | @item ENAMETOOLONG |
---|
535 | Length of a filename string exceeds PATH_MAX and _POSIX_NO_TRUNC is in |
---|
536 | effect. |
---|
537 | |
---|
538 | @item ENFILE |
---|
539 | Too many files are currently open in the system. |
---|
540 | |
---|
541 | @item ENOENT |
---|
542 | A file or directory does not exist. |
---|
543 | |
---|
544 | @item ENOSPC |
---|
545 | No space left on disk. |
---|
546 | |
---|
547 | @item ENOTDIR |
---|
548 | A component of the specified pathname was not a directory when a directory |
---|
549 | was expected. |
---|
550 | |
---|
551 | @item ENXIO |
---|
552 | No such device. This error may also occur when a device is not ready, for |
---|
553 | example, a tape drive is off-line. |
---|
554 | |
---|
555 | @item EROFS |
---|
556 | Read-only file system. |
---|
557 | @end table |
---|
558 | |
---|
559 | @subheading DESCRIPTION: |
---|
560 | |
---|
561 | The @code{open} function establishes a connection between a file and a file |
---|
562 | descriptor. The file descriptor is a small integer that is used by I/O |
---|
563 | functions to reference the file. The @code{path} argument points to the |
---|
564 | pathname for the file. |
---|
565 | |
---|
566 | The @code{oflag} argument is the bitwise inclusive OR of the values of |
---|
567 | symbolic constants. The programmer must specify exactly one of the following |
---|
568 | three symbols: |
---|
569 | |
---|
570 | @table @b |
---|
571 | @item O_RDONLY |
---|
572 | Open for reading only. |
---|
573 | |
---|
574 | @item O_WRONLY |
---|
575 | Open for writing only. |
---|
576 | |
---|
577 | @item O_RDWR |
---|
578 | Open for reading and writing. |
---|
579 | |
---|
580 | @end table |
---|
581 | |
---|
582 | Any combination of the following symbols may also be used. |
---|
583 | |
---|
584 | @table @b |
---|
585 | @item O_APPEND |
---|
586 | Set the file offset to the end-of-file prior to each write. |
---|
587 | |
---|
588 | @item O_CREAT |
---|
589 | If the file does not exist, allow it to be created. This flag indicates |
---|
590 | that the @code{mode} argument is present in the call to @code{open}. |
---|
591 | |
---|
592 | @item O_EXCL |
---|
593 | This flag may be used only if O_CREAT is also set. It causes the call |
---|
594 | to @code{open} to fail if the file already exists. |
---|
595 | |
---|
596 | @item O_NOCTTY |
---|
597 | If @code{path} identifies a terminal, this flag prevents that teminal from |
---|
598 | becoming the controlling terminal for thi9s process. See Chapter 8 for a |
---|
599 | description of terminal I/O. |
---|
600 | |
---|
601 | @item O_NONBLOCK |
---|
602 | Do no wait for the device or file to be ready or available. After the file |
---|
603 | is open, the @code{read} and @code{write} calls return immediately. If the |
---|
604 | process would be delayed in the read or write opermation, -1 is returned and |
---|
605 | @code{errno} is set to @code{EAGAIN} instead of blocking the caller. |
---|
606 | |
---|
607 | @item O_TRUNC |
---|
608 | This flag should be used only on ordinary files opened for writing. It |
---|
609 | causes the file to be tuncated to zero length.. |
---|
610 | |
---|
611 | @end table |
---|
612 | |
---|
613 | Upon successful completion, @code{open} returns a non-negative file |
---|
614 | descriptor. |
---|
615 | |
---|
616 | @subheading NOTES: |
---|
617 | |
---|
618 | NONE |
---|
619 | |
---|
620 | @c |
---|
621 | @c |
---|
622 | @c |
---|
623 | @page |
---|
624 | @subsection creat - Create a new file or rewrite an existing one |
---|
625 | |
---|
626 | @findex creat |
---|
627 | @cindex create a new file or rewrite an existing one |
---|
628 | |
---|
629 | @subheading CALLING SEQUENCE: |
---|
630 | |
---|
631 | @ifset is-C |
---|
632 | @example |
---|
633 | #include <sys/types.h> |
---|
634 | #include <sys/stat.h> |
---|
635 | #include <fcntl.h> |
---|
636 | |
---|
637 | int creat( |
---|
638 | const char *path, |
---|
639 | mode_t mode |
---|
640 | ); |
---|
641 | @end example |
---|
642 | @end ifset |
---|
643 | |
---|
644 | @ifset is-Ada |
---|
645 | @end ifset |
---|
646 | |
---|
647 | @subheading STATUS CODES: |
---|
648 | |
---|
649 | @table @b |
---|
650 | @item EEXIST |
---|
651 | @code{path} already exists and O_CREAT and O_EXCL were used. |
---|
652 | |
---|
653 | @item EISDIR |
---|
654 | @code{path} refers to a directory and the access requested involved |
---|
655 | writing |
---|
656 | |
---|
657 | @item ETXTBSY |
---|
658 | @code{path} refers to an executable image which is currently being |
---|
659 | executed and write access was requested |
---|
660 | |
---|
661 | @item EFAULT |
---|
662 | @code{path} points outside your accessible address space |
---|
663 | |
---|
664 | @item EACCES |
---|
665 | The requested access to the file is not allowed, or one of the |
---|
666 | directories in @code{path} did not allow search (execute) permission. |
---|
667 | |
---|
668 | @item ENAMETOOLONG |
---|
669 | @code{path} was too long. |
---|
670 | |
---|
671 | @item ENOENT |
---|
672 | A directory component in @code{path} does not exist or is a dangling |
---|
673 | symbolic link. |
---|
674 | |
---|
675 | @item ENOTDIR |
---|
676 | A component used as a directory in @code{path} is not, in fact, a |
---|
677 | directory. |
---|
678 | |
---|
679 | @item EMFILE |
---|
680 | The process alreadyh has the maximum number of files open. |
---|
681 | |
---|
682 | @item ENFILE |
---|
683 | The limit on the total number of files open on the system has been |
---|
684 | reached. |
---|
685 | |
---|
686 | @item ENOMEM |
---|
687 | Insufficient kernel memory was available. |
---|
688 | |
---|
689 | @item EROFS |
---|
690 | @code{path} refers to a file on a read-only filesystem and write access |
---|
691 | was requested |
---|
692 | |
---|
693 | @end table |
---|
694 | |
---|
695 | @subheading DESCRIPTION: |
---|
696 | |
---|
697 | @code{creat} attempts to create a file and return a file descriptor for |
---|
698 | use in read, write, etc. |
---|
699 | |
---|
700 | @subheading NOTES: |
---|
701 | |
---|
702 | NONE |
---|
703 | |
---|
704 | The routine is implemented in Cygnus newlib. |
---|
705 | |
---|
706 | @c |
---|
707 | @c |
---|
708 | @c |
---|
709 | @page |
---|
710 | @subsection umask - Sets a file creation mask. |
---|
711 | |
---|
712 | @findex umask |
---|
713 | @cindex sets a file creation mask. |
---|
714 | |
---|
715 | @subheading CALLING SEQUENCE: |
---|
716 | |
---|
717 | @ifset is-C |
---|
718 | @example |
---|
719 | #include <sys/types.h> |
---|
720 | #include <sys/stat.h> |
---|
721 | |
---|
722 | mode_t umask( |
---|
723 | mode_t cmask |
---|
724 | ); |
---|
725 | @end example |
---|
726 | @end ifset |
---|
727 | |
---|
728 | @ifset is-Ada |
---|
729 | @end ifset |
---|
730 | |
---|
731 | @subheading STATUS CODES: |
---|
732 | |
---|
733 | @subheading DESCRIPTION: |
---|
734 | |
---|
735 | The @code{umask()} function sets the process file creation mask to @code{cmask}. |
---|
736 | The file creation mask is used during @code{open()}, @code{creat()}, @code{mkdir()}, |
---|
737 | @code{mkfifo()} calls to turn off permission bits in the @code{mode} argument. |
---|
738 | Bit positions that are set in @code{cmask} are cleared in the mode of the |
---|
739 | created file. |
---|
740 | |
---|
741 | @subheading NOTES: |
---|
742 | |
---|
743 | NONE |
---|
744 | |
---|
745 | The @code{cmask} argument should have only permission bits set. All other |
---|
746 | bits should be zero. |
---|
747 | |
---|
748 | In a system which supports multiple processes, the file creation mask is inherited |
---|
749 | across @code{fork()} and @code{exec()} calls. This makes it possible to alter the |
---|
750 | default permission bits of created files. RTEMS does not support multiple processes |
---|
751 | so this behavior is not possible. |
---|
752 | |
---|
753 | @c |
---|
754 | @c |
---|
755 | @c |
---|
756 | @page |
---|
757 | @subsection link - Creates a link to a file |
---|
758 | |
---|
759 | @findex link |
---|
760 | @cindex creates a link to a file |
---|
761 | |
---|
762 | @subheading CALLING SEQUENCE: |
---|
763 | |
---|
764 | @ifset is-C |
---|
765 | @example |
---|
766 | #include <unistd.h> |
---|
767 | |
---|
768 | int link( |
---|
769 | const char *existing, |
---|
770 | const char *new |
---|
771 | ); |
---|
772 | @end example |
---|
773 | @end ifset |
---|
774 | |
---|
775 | @ifset is-Ada |
---|
776 | @end ifset |
---|
777 | |
---|
778 | @subheading STATUS CODES: |
---|
779 | |
---|
780 | @table @b |
---|
781 | |
---|
782 | @item EACCES |
---|
783 | Search permission is denied for a directory in a file's path prefix |
---|
784 | |
---|
785 | @item EEXIST |
---|
786 | The named file already exists. |
---|
787 | |
---|
788 | @item EMLINK |
---|
789 | The number of links would exceed @code{LINK_MAX}. |
---|
790 | |
---|
791 | @item ENAMETOOLONG |
---|
792 | Length of a filename string exceeds PATH_MAX and _POSIX_NO_TRUNC is in |
---|
793 | effect. |
---|
794 | |
---|
795 | @item ENOENT |
---|
796 | A file or directory does not exist. |
---|
797 | @item ENOSPC |
---|
798 | No space left on disk. |
---|
799 | |
---|
800 | @item ENOTDIR |
---|
801 | A component of the specified pathname was not a directory when a directory |
---|
802 | was expected. |
---|
803 | |
---|
804 | @item EPERM |
---|
805 | Operation is not permitted. Process does not have the appropriate priviledges |
---|
806 | or permissions to perform the requested operations. |
---|
807 | |
---|
808 | @item EROFS |
---|
809 | Read-only file system. |
---|
810 | |
---|
811 | @item EXDEV |
---|
812 | Attempt to link a file to another file system. |
---|
813 | |
---|
814 | @end table |
---|
815 | |
---|
816 | @subheading DESCRIPTION: |
---|
817 | |
---|
818 | The @code{link()} function atomically creates a new link for an existing file |
---|
819 | and increments the link count for the file. |
---|
820 | |
---|
821 | If the @code{link()} function fails, no directories are modified. |
---|
822 | |
---|
823 | The @code{existing} argument should not be a directory. |
---|
824 | |
---|
825 | The caller may (or may not) need permission to access the existing file. |
---|
826 | |
---|
827 | @subheading NOTES: |
---|
828 | |
---|
829 | NONE |
---|
830 | |
---|
831 | @c |
---|
832 | @c |
---|
833 | @c |
---|
834 | @page |
---|
835 | @subsection symlink - Creates a symbolic link to a file |
---|
836 | |
---|
837 | @findex symlink |
---|
838 | @cindex creates a symbolic link to a file |
---|
839 | |
---|
840 | @subheading CALLING SEQUENCE: |
---|
841 | |
---|
842 | @ifset is-C |
---|
843 | @example |
---|
844 | #include <unistd.h> |
---|
845 | |
---|
846 | int symlink( |
---|
847 | const char *topath, |
---|
848 | const char *frompath |
---|
849 | ); |
---|
850 | @end example |
---|
851 | @end ifset |
---|
852 | |
---|
853 | @ifset is-Ada |
---|
854 | @end ifset |
---|
855 | |
---|
856 | @subheading STATUS CODES: |
---|
857 | |
---|
858 | @table @b |
---|
859 | |
---|
860 | @item EACCES |
---|
861 | Search permission is denied for a directory in a file's path prefix |
---|
862 | |
---|
863 | @item EEXIST |
---|
864 | The named file already exists. |
---|
865 | |
---|
866 | @item ENAMETOOLONG |
---|
867 | Length of a filename string exceeds PATH_MAX and _POSIX_NO_TRUNC is in |
---|
868 | effect. |
---|
869 | |
---|
870 | @item ENOENT |
---|
871 | A file or directory does not exist. |
---|
872 | |
---|
873 | @item ENOSPC |
---|
874 | No space left on disk. |
---|
875 | |
---|
876 | @item ENOTDIR |
---|
877 | A component of the specified pathname was not a directory when a directory |
---|
878 | was expected. |
---|
879 | |
---|
880 | @item EPERM |
---|
881 | Operation is not permitted. Process does not have the appropriate priviledges |
---|
882 | or permissions to perform the requested operations. |
---|
883 | |
---|
884 | @item EROFS |
---|
885 | Read-only file system. |
---|
886 | |
---|
887 | @end table |
---|
888 | |
---|
889 | @subheading DESCRIPTION: |
---|
890 | |
---|
891 | The @code{symlink()} function creates a symbolic link from the frombath to the |
---|
892 | topath. The symbolic link will be interpreted at run-time. |
---|
893 | |
---|
894 | If the @code{symlink()} function fails, no directories are modified. |
---|
895 | |
---|
896 | The caller may (or may not) need permission to access the existing file. |
---|
897 | |
---|
898 | @subheading NOTES: |
---|
899 | |
---|
900 | NONE |
---|
901 | |
---|
902 | @c |
---|
903 | @c |
---|
904 | @c |
---|
905 | @page |
---|
906 | @subsection readlink - Obtain the name of a symbolic link destination |
---|
907 | |
---|
908 | @findex readlink |
---|
909 | @cindex obtain the name of a symbolic link destination |
---|
910 | |
---|
911 | @subheading CALLING SEQUENCE: |
---|
912 | |
---|
913 | @ifset is-C |
---|
914 | @example |
---|
915 | #include <unistd.h> |
---|
916 | |
---|
917 | int readlink( |
---|
918 | const char *path, |
---|
919 | char *buf, |
---|
920 | size_t bufsize |
---|
921 | ); |
---|
922 | |
---|
923 | @end example |
---|
924 | @end ifset |
---|
925 | |
---|
926 | @ifset is-Ada |
---|
927 | @end ifset |
---|
928 | |
---|
929 | @subheading STATUS CODES: |
---|
930 | |
---|
931 | @table @b |
---|
932 | |
---|
933 | @item EACCES |
---|
934 | Search permission is denied for a directory in a file's path prefix |
---|
935 | |
---|
936 | @item ENAMETOOLONG |
---|
937 | Length of a filename string exceeds PATH_MAX and _POSIX_NO_TRUNC is in |
---|
938 | effect. |
---|
939 | |
---|
940 | @item ENOENT |
---|
941 | A file or directory does not exist. |
---|
942 | |
---|
943 | @item ENOTDIR |
---|
944 | A component of the prefix pathname was not a directory when a directory |
---|
945 | was expected. |
---|
946 | |
---|
947 | @item ELOOP |
---|
948 | Too many symbolic links were encountered in the pathname. |
---|
949 | |
---|
950 | @item EINVAL |
---|
951 | The pathname does not refer to a symbolic link |
---|
952 | |
---|
953 | @item EFAULT |
---|
954 | An invalid pointer was passed into the @code{readlink()} routine. |
---|
955 | |
---|
956 | @end table |
---|
957 | |
---|
958 | @subheading DESCRIPTION: |
---|
959 | |
---|
960 | The @code{readlink()} function places the symbolic link destination into |
---|
961 | @code{buf} argument and returns the number of characters copied. |
---|
962 | |
---|
963 | If the symbolic link destination is longer than bufsize characters the |
---|
964 | name will be truncated. |
---|
965 | |
---|
966 | @subheading NOTES: |
---|
967 | |
---|
968 | NONE |
---|
969 | |
---|
970 | @c |
---|
971 | @c |
---|
972 | @c |
---|
973 | @page |
---|
974 | @subsection mkdir - Makes a directory |
---|
975 | |
---|
976 | @findex mkdir |
---|
977 | @cindex makes a directory |
---|
978 | |
---|
979 | @subheading CALLING SEQUENCE: |
---|
980 | |
---|
981 | @ifset is-C |
---|
982 | @example |
---|
983 | #include <sys/types.h> |
---|
984 | #include <sys/stat.h> |
---|
985 | |
---|
986 | int mkdir( |
---|
987 | const char *path, |
---|
988 | mode_t mode |
---|
989 | ); |
---|
990 | @end example |
---|
991 | @end ifset |
---|
992 | |
---|
993 | @ifset is-Ada |
---|
994 | @end ifset |
---|
995 | |
---|
996 | @subheading STATUS CODES: |
---|
997 | |
---|
998 | @table @b |
---|
999 | @item EACCES |
---|
1000 | Search permission is denied for a directory in a file's path prefix |
---|
1001 | |
---|
1002 | @item EEXIST |
---|
1003 | The name file already exist. |
---|
1004 | |
---|
1005 | @item EMLINK |
---|
1006 | The number of links would exceed LINK_MAX |
---|
1007 | |
---|
1008 | @item ENAMETOOLONG |
---|
1009 | Length of a filename string exceeds PATH_MAX and _POSIX_NO_TRUNC is in |
---|
1010 | effect. |
---|
1011 | |
---|
1012 | @item ENOENT |
---|
1013 | A file or directory does not exist. |
---|
1014 | |
---|
1015 | @item ENOSPC |
---|
1016 | No space left on disk. |
---|
1017 | |
---|
1018 | @item ENOTDIR |
---|
1019 | A component of the specified pathname was not a directory when a directory |
---|
1020 | was expected. |
---|
1021 | |
---|
1022 | @item EROFS |
---|
1023 | Read-only file system. |
---|
1024 | |
---|
1025 | @end table |
---|
1026 | |
---|
1027 | @subheading DESCRIPTION: |
---|
1028 | |
---|
1029 | The @code{mkdir()} function creates a new diectory named @code{path}. The |
---|
1030 | permission bits (modified by the file creation mask) are set from @code{mode}. |
---|
1031 | The owner and group IDs for the directory are set from the effective user ID |
---|
1032 | and group ID. |
---|
1033 | |
---|
1034 | The new directory may (or may not) contain entries for.. and .. but is otherwise |
---|
1035 | empty. |
---|
1036 | |
---|
1037 | @subheading NOTES: |
---|
1038 | |
---|
1039 | NONE |
---|
1040 | |
---|
1041 | @c |
---|
1042 | @c |
---|
1043 | @c |
---|
1044 | @page |
---|
1045 | @subsection mkfifo - Makes a FIFO special file |
---|
1046 | |
---|
1047 | @findex mkfifo |
---|
1048 | @cindex makes a fifo special file |
---|
1049 | |
---|
1050 | @subheading CALLING SEQUENCE: |
---|
1051 | |
---|
1052 | @ifset is-C |
---|
1053 | @example |
---|
1054 | #include <sys/types.h> |
---|
1055 | #include <sys/stat.h> |
---|
1056 | |
---|
1057 | |
---|
1058 | int mkfifo( |
---|
1059 | const char *path, |
---|
1060 | mode_t mode |
---|
1061 | ); |
---|
1062 | @end example |
---|
1063 | @end ifset |
---|
1064 | |
---|
1065 | @ifset is-Ada |
---|
1066 | @end ifset |
---|
1067 | |
---|
1068 | @subheading STATUS CODES: |
---|
1069 | |
---|
1070 | @table @b |
---|
1071 | @item EACCES |
---|
1072 | Search permission is denied for a directory in a file's path prefix |
---|
1073 | |
---|
1074 | @item EEXIST |
---|
1075 | The named file already exists. |
---|
1076 | |
---|
1077 | @item ENOENT |
---|
1078 | A file or directory does not exist. |
---|
1079 | |
---|
1080 | @item ENOSPC |
---|
1081 | No space left on disk. |
---|
1082 | |
---|
1083 | @item ENOTDIR |
---|
1084 | A component of the specified @code{path} was not a directory when a directory |
---|
1085 | was expected. |
---|
1086 | |
---|
1087 | @item EROFS |
---|
1088 | Read-only file system. |
---|
1089 | |
---|
1090 | @end table |
---|
1091 | |
---|
1092 | @subheading DESCRIPTION: |
---|
1093 | |
---|
1094 | The @code{mkfifo()} function creates a new FIFO special file named @code{path}. |
---|
1095 | The permission bits (modified by the file creation mask) are set from |
---|
1096 | @code{mode}. The owner and group IDs for the FIFO are set from the efective |
---|
1097 | user ID and group ID. |
---|
1098 | |
---|
1099 | @subheading NOTES: |
---|
1100 | |
---|
1101 | NONE |
---|
1102 | |
---|
1103 | @c |
---|
1104 | @c |
---|
1105 | @c |
---|
1106 | @page |
---|
1107 | @subsection unlink - Removes a directory entry |
---|
1108 | |
---|
1109 | @findex unlink |
---|
1110 | @cindex removes a directory entry |
---|
1111 | |
---|
1112 | @subheading CALLING SEQUENCE: |
---|
1113 | |
---|
1114 | @ifset is-C |
---|
1115 | @example |
---|
1116 | #include <unistd.h> |
---|
1117 | |
---|
1118 | int unlink( |
---|
1119 | const char path |
---|
1120 | ); |
---|
1121 | @end example |
---|
1122 | @end ifset |
---|
1123 | |
---|
1124 | @ifset is-Ada |
---|
1125 | @end ifset |
---|
1126 | |
---|
1127 | @subheading STATUS CODES: |
---|
1128 | |
---|
1129 | @table @b |
---|
1130 | @item EACCES |
---|
1131 | Search permission is denied for a directory in a file's path prefix |
---|
1132 | |
---|
1133 | @item EBUSY |
---|
1134 | The directory is in use. |
---|
1135 | |
---|
1136 | @item ENAMETOOLONG |
---|
1137 | Length of a filename string exceeds PATH_MAX and _POSIX_NO_TRUNC is in |
---|
1138 | effect. |
---|
1139 | |
---|
1140 | @item ENOENT |
---|
1141 | A file or directory does not exist. |
---|
1142 | |
---|
1143 | @item ENOTDIR |
---|
1144 | A component of the specified @code{path} was not a directory when a directory |
---|
1145 | was expected. |
---|
1146 | |
---|
1147 | @item EPERM |
---|
1148 | Operation is not permitted. Process does not have the appropriate priviledges |
---|
1149 | or permissions to perform the requested operations. |
---|
1150 | |
---|
1151 | @item EROFS |
---|
1152 | Read-only file system. |
---|
1153 | |
---|
1154 | @end table |
---|
1155 | |
---|
1156 | @subheading DESCRIPTION: |
---|
1157 | |
---|
1158 | The @code{unlink} function removes the link named by @code{path} and decrements the |
---|
1159 | link count of the file referenced by the link. When the link count goes to zero |
---|
1160 | and no process has the file open, the space occupied by the file is freed and the |
---|
1161 | file is no longer accessible. |
---|
1162 | |
---|
1163 | @subheading NOTES: |
---|
1164 | |
---|
1165 | NONE |
---|
1166 | |
---|
1167 | @c |
---|
1168 | @c |
---|
1169 | @c |
---|
1170 | @page |
---|
1171 | @subsection rmdir - Delete a directory |
---|
1172 | |
---|
1173 | @findex rmdir |
---|
1174 | @cindex delete a directory |
---|
1175 | |
---|
1176 | @subheading CALLING SEQUENCE: |
---|
1177 | |
---|
1178 | @ifset is-C |
---|
1179 | @example |
---|
1180 | #include <unistd.h> |
---|
1181 | |
---|
1182 | int rmdir( |
---|
1183 | const char *pathname |
---|
1184 | ); |
---|
1185 | @end example |
---|
1186 | @end ifset |
---|
1187 | |
---|
1188 | @ifset is-Ada |
---|
1189 | @end ifset |
---|
1190 | |
---|
1191 | @subheading STATUS CODES: |
---|
1192 | |
---|
1193 | @table @b |
---|
1194 | @item EPERM |
---|
1195 | The filesystem containing @code{pathname} does not support the removal |
---|
1196 | of directories. |
---|
1197 | |
---|
1198 | @item EFAULT |
---|
1199 | @code{pathname} points ouside your accessible address space. |
---|
1200 | |
---|
1201 | @item EACCES |
---|
1202 | Write access to the directory containing @code{pathname} was not |
---|
1203 | allowed for the process's effective uid, or one of the directories in |
---|
1204 | @code{pathname} did not allow search (execute) permission. |
---|
1205 | |
---|
1206 | @item EPERM |
---|
1207 | The directory containing @code{pathname} has the stickybit (S_ISVTX) |
---|
1208 | set and the process's effective uid is neither the uid of the file to |
---|
1209 | be delected nor that of the director containing it. |
---|
1210 | |
---|
1211 | @item ENAMETOOLONG |
---|
1212 | @code{pathname} was too long. |
---|
1213 | |
---|
1214 | @item ENOENT |
---|
1215 | A dirctory component in @code{pathname} does not exist or is a |
---|
1216 | dangling symbolic link. |
---|
1217 | |
---|
1218 | @item ENOTDIR |
---|
1219 | @code{pathname}, or a component used as a directory in @code{pathname}, |
---|
1220 | is not, in fact, a directory. |
---|
1221 | |
---|
1222 | @item ENOTEMPTY |
---|
1223 | @code{pathname} contains entries other than . and .. . |
---|
1224 | |
---|
1225 | @item EBUSY |
---|
1226 | @code{pathname} is the current working directory or root directory of |
---|
1227 | some process |
---|
1228 | |
---|
1229 | @item EBUSY |
---|
1230 | @code{pathname} is the current directory or root directory of some |
---|
1231 | process. |
---|
1232 | |
---|
1233 | @item ENOMEM |
---|
1234 | Insufficient kernel memory was available |
---|
1235 | |
---|
1236 | @item EROGS |
---|
1237 | @code{pathname} refers to a file on a read-only filesystem. |
---|
1238 | |
---|
1239 | @item ELOOP |
---|
1240 | @code{pathname} contains a reference to a circular symbolic link |
---|
1241 | |
---|
1242 | @end table |
---|
1243 | |
---|
1244 | @subheading DESCRIPTION: |
---|
1245 | |
---|
1246 | @code{rmdir} deletes a directory, which must be empty |
---|
1247 | |
---|
1248 | |
---|
1249 | @subheading NOTES: |
---|
1250 | |
---|
1251 | NONE |
---|
1252 | |
---|
1253 | @c |
---|
1254 | @c |
---|
1255 | @c |
---|
1256 | @page |
---|
1257 | @subsection rename - Renames a file |
---|
1258 | |
---|
1259 | @findex rename |
---|
1260 | @cindex renames a file |
---|
1261 | |
---|
1262 | @subheading CALLING SEQUENCE: |
---|
1263 | |
---|
1264 | @ifset is-C |
---|
1265 | @example |
---|
1266 | #include <unistd.h> |
---|
1267 | |
---|
1268 | int rename( |
---|
1269 | const char *old, |
---|
1270 | const char *new |
---|
1271 | ); |
---|
1272 | @end example |
---|
1273 | @end ifset |
---|
1274 | |
---|
1275 | @ifset is-Ada |
---|
1276 | @end ifset |
---|
1277 | |
---|
1278 | @subheading STATUS CODES: |
---|
1279 | |
---|
1280 | @table @b |
---|
1281 | @item EACCES |
---|
1282 | Search permission is denied for a directory in a file's path prefix. |
---|
1283 | |
---|
1284 | @item EBUSY |
---|
1285 | The directory is in use. |
---|
1286 | |
---|
1287 | @item EEXIST |
---|
1288 | The named file already exists. |
---|
1289 | |
---|
1290 | @item EINVAL |
---|
1291 | Invalid argument. |
---|
1292 | |
---|
1293 | @item EISDIR |
---|
1294 | Attempt to open a directory for writing or to rename a file to be a |
---|
1295 | directory. |
---|
1296 | |
---|
1297 | @item EMLINK |
---|
1298 | The number of links would exceed LINK_MAX. |
---|
1299 | |
---|
1300 | @item ENAMETOOLONG |
---|
1301 | Length of a filename string exceeds PATH_MAX and _POSIX_NO_TRUNC is |
---|
1302 | in effect. |
---|
1303 | |
---|
1304 | @item ENOENT |
---|
1305 | A file or directory does no exist. |
---|
1306 | |
---|
1307 | @item ENOSPC |
---|
1308 | No space left on disk. |
---|
1309 | |
---|
1310 | @item ENOTDIR |
---|
1311 | A component of the specified pathname was not a directory when a |
---|
1312 | directory was expected. |
---|
1313 | |
---|
1314 | @item ENOTEMPTY |
---|
1315 | Attempt to delete or rename a non-empty directory. |
---|
1316 | |
---|
1317 | @item EROFS |
---|
1318 | Read-only file system |
---|
1319 | |
---|
1320 | @item EXDEV |
---|
1321 | Attempt to link a file to another file system. |
---|
1322 | @end table |
---|
1323 | |
---|
1324 | @subheading DESCRIPTION: |
---|
1325 | |
---|
1326 | The @code{rename()} function causes the file known bo @code{old} to |
---|
1327 | now be known as @code{new}. |
---|
1328 | |
---|
1329 | Ordinary files may be renamed to ordinary files, and directories may be |
---|
1330 | renamed to directories; however, files cannot be converted using |
---|
1331 | @code{rename()}. The @code{new} pathname may not contain a path prefix |
---|
1332 | of @code{old}. |
---|
1333 | |
---|
1334 | @subheading NOTES: |
---|
1335 | |
---|
1336 | If a file already exists by the name @code{new}, it is removed. The |
---|
1337 | @code{rename()} function is atomic. If the @code{rename()} detects an |
---|
1338 | error, no files are removed. This guarantees that the |
---|
1339 | @code{rename("x", "x")} does not remove @code{x}. |
---|
1340 | |
---|
1341 | You may not rename dot or dot-dot. |
---|
1342 | |
---|
1343 | The routine is implemented in Cygnus newlib using @code{link()} and |
---|
1344 | @code{unlink()}. |
---|
1345 | |
---|
1346 | @c |
---|
1347 | @c |
---|
1348 | @c |
---|
1349 | @page |
---|
1350 | @subsection stat - Gets information about a file |
---|
1351 | |
---|
1352 | @findex stat |
---|
1353 | @cindex gets information about a file |
---|
1354 | |
---|
1355 | @subheading CALLING SEQUENCE: |
---|
1356 | |
---|
1357 | @ifset is-C |
---|
1358 | @example |
---|
1359 | #include <sys/types.h> |
---|
1360 | #include <sys/stat.h> |
---|
1361 | |
---|
1362 | int stat( |
---|
1363 | const char *path, |
---|
1364 | struct stat *buf |
---|
1365 | ); |
---|
1366 | @end example |
---|
1367 | @end ifset |
---|
1368 | |
---|
1369 | @ifset is-Ada |
---|
1370 | @end ifset |
---|
1371 | |
---|
1372 | @subheading STATUS CODES: |
---|
1373 | |
---|
1374 | @table @b |
---|
1375 | @item EACCES |
---|
1376 | Search permission is denied for a directory in a file's path prefix. |
---|
1377 | |
---|
1378 | @item EBADF |
---|
1379 | Invalid file descriptor. |
---|
1380 | |
---|
1381 | @item ENAMETOOLONG |
---|
1382 | Length of a filename string exceeds PATH_MAX and _POSIX_NO_TRUNC is |
---|
1383 | in effect. |
---|
1384 | |
---|
1385 | @item ENOENT |
---|
1386 | A file or directory does not exist. |
---|
1387 | |
---|
1388 | @item ENOTDIR |
---|
1389 | A component of the specified pathname was not a directory when a |
---|
1390 | directory was expected. |
---|
1391 | |
---|
1392 | @end table |
---|
1393 | |
---|
1394 | @subheading DESCRIPTION: |
---|
1395 | |
---|
1396 | The @code{path} argument points to a pathname for a file. Read, write, or |
---|
1397 | execute permission for the file is not required, but all directories listed |
---|
1398 | in @code{path} must be searchable. The @code{stat()} function obtains |
---|
1399 | information about the named file and writes it to the area pointed to by |
---|
1400 | @code{buf}. |
---|
1401 | |
---|
1402 | @subheading NOTES: |
---|
1403 | |
---|
1404 | NONE |
---|
1405 | |
---|
1406 | @c |
---|
1407 | @c |
---|
1408 | @c |
---|
1409 | @page |
---|
1410 | @subsection fstat - Gets file status |
---|
1411 | |
---|
1412 | @findex fstat |
---|
1413 | @cindex gets file status |
---|
1414 | |
---|
1415 | @subheading CALLING SEQUENCE: |
---|
1416 | |
---|
1417 | @ifset is-C |
---|
1418 | @example |
---|
1419 | #include <sys/types.h> |
---|
1420 | #include <sys/stat.h> |
---|
1421 | |
---|
1422 | int fstat( |
---|
1423 | int fildes, |
---|
1424 | struct stat *buf |
---|
1425 | ); |
---|
1426 | @end example |
---|
1427 | @end ifset |
---|
1428 | |
---|
1429 | @ifset is-Ada |
---|
1430 | @end ifset |
---|
1431 | |
---|
1432 | @subheading STATUS CODES: |
---|
1433 | |
---|
1434 | @table @b |
---|
1435 | @item EBADF |
---|
1436 | Invalid file descriptor |
---|
1437 | |
---|
1438 | @end table |
---|
1439 | |
---|
1440 | @subheading DESCRIPTION: |
---|
1441 | |
---|
1442 | The @code{fstat()} function obtains information about the file |
---|
1443 | associated with @code{fildes} and writes it to the area pointed |
---|
1444 | to by the @code{buf} argument. |
---|
1445 | |
---|
1446 | @subheading NOTES: |
---|
1447 | |
---|
1448 | If the filesystem object referred to by @code{fildes} is a |
---|
1449 | link, then the information returned in @code{buf} refers |
---|
1450 | to the destination of that link. This is in contrast to |
---|
1451 | @code{lstat()} which does not follow the link. |
---|
1452 | |
---|
1453 | @c |
---|
1454 | @c |
---|
1455 | @c |
---|
1456 | @page |
---|
1457 | @subsection lstat - Gets file status |
---|
1458 | |
---|
1459 | @findex lstat |
---|
1460 | @cindex gets file status |
---|
1461 | |
---|
1462 | @subheading CALLING SEQUENCE: |
---|
1463 | |
---|
1464 | @ifset is-C |
---|
1465 | @example |
---|
1466 | #include <sys/types.h> |
---|
1467 | #include <sys/stat.h> |
---|
1468 | |
---|
1469 | int lstat( |
---|
1470 | int fildes, |
---|
1471 | struct stat *buf |
---|
1472 | ); |
---|
1473 | @end example |
---|
1474 | @end ifset |
---|
1475 | |
---|
1476 | @ifset is-Ada |
---|
1477 | @end ifset |
---|
1478 | |
---|
1479 | @subheading STATUS CODES: |
---|
1480 | |
---|
1481 | @table @b |
---|
1482 | @item EBADF |
---|
1483 | Invalid file descriptor |
---|
1484 | |
---|
1485 | @end table |
---|
1486 | |
---|
1487 | @subheading DESCRIPTION: |
---|
1488 | |
---|
1489 | The @code{lstat()} function obtains information about the file |
---|
1490 | associated with @code{fildes} and writes it to the area pointed |
---|
1491 | to by the @code{buf} argument. |
---|
1492 | |
---|
1493 | @subheading NOTES: |
---|
1494 | |
---|
1495 | If the filesystem object referred to by @code{fildes} is a |
---|
1496 | link, then the information returned in @code{buf} refers |
---|
1497 | to the link itself. This is in contrast to @code{fstat()} |
---|
1498 | which follows the link. |
---|
1499 | |
---|
1500 | The @code{lstat()} routine is defined by BSD 4.3 and SVR4 |
---|
1501 | and not included in POSIX 1003.1b-1996. |
---|
1502 | |
---|
1503 | @c |
---|
1504 | @c |
---|
1505 | @c |
---|
1506 | @page |
---|
1507 | @subsection access - Check permissions for a file |
---|
1508 | |
---|
1509 | @findex access |
---|
1510 | @cindex check permissions for a file |
---|
1511 | |
---|
1512 | @subheading CALLING SEQUENCE: |
---|
1513 | |
---|
1514 | @ifset is-C |
---|
1515 | @example |
---|
1516 | #include <unistd.h> |
---|
1517 | |
---|
1518 | int access( |
---|
1519 | const char *pathname, |
---|
1520 | int mode |
---|
1521 | ); |
---|
1522 | @end example |
---|
1523 | @end ifset |
---|
1524 | |
---|
1525 | @ifset is-Ada |
---|
1526 | @end ifset |
---|
1527 | |
---|
1528 | @subheading STATUS CODES: |
---|
1529 | |
---|
1530 | @table @b |
---|
1531 | @item EACCES |
---|
1532 | The requested access would be denied, either to the file itself or |
---|
1533 | one of the directories in @code{pathname}. |
---|
1534 | |
---|
1535 | @item EFAULT |
---|
1536 | @code{pathname} points outside your accessible address space. |
---|
1537 | |
---|
1538 | @item EINVAL |
---|
1539 | @code{Mode} was incorrectly specified. |
---|
1540 | |
---|
1541 | @item ENAMETOOLONG |
---|
1542 | @code{pathname} is too long. |
---|
1543 | |
---|
1544 | @item ENOENT |
---|
1545 | A directory component in @code{pathname} would have been accessible but |
---|
1546 | does not exist or was a dangling symbolic link. |
---|
1547 | |
---|
1548 | @item ENOTDIR |
---|
1549 | A component used as a directory in @code{pathname} is not, in fact, |
---|
1550 | a directory. |
---|
1551 | |
---|
1552 | @item ENOMEM |
---|
1553 | Insufficient kernel memory was available. |
---|
1554 | |
---|
1555 | @end table |
---|
1556 | |
---|
1557 | @subheading DESCRIPTION: |
---|
1558 | |
---|
1559 | @code{Access} checks whether the process would be allowed to read, write or |
---|
1560 | test for existence of the file (or other file system object) whose name is |
---|
1561 | @code{pathname}. If @code{pathname} is a symbolic link permissions of the |
---|
1562 | file referred by this symbolic link are tested. |
---|
1563 | |
---|
1564 | @code{Mode} is a mask consisting of one or more of R_OK, W_OK, X_OK and F_OK. |
---|
1565 | |
---|
1566 | @subheading NOTES: |
---|
1567 | |
---|
1568 | NONE |
---|
1569 | |
---|
1570 | @c |
---|
1571 | @c |
---|
1572 | @c |
---|
1573 | @page |
---|
1574 | @subsection chmod - Changes file mode. |
---|
1575 | |
---|
1576 | @findex chmod |
---|
1577 | @cindex changes file mode. |
---|
1578 | |
---|
1579 | @subheading CALLING SEQUENCE: |
---|
1580 | |
---|
1581 | @ifset is-C |
---|
1582 | @example |
---|
1583 | #include <sys/types.h> |
---|
1584 | #include <sys/stat.h> |
---|
1585 | |
---|
1586 | int chmod( |
---|
1587 | const char *path, |
---|
1588 | mode_t mode |
---|
1589 | ); |
---|
1590 | @end example |
---|
1591 | @end ifset |
---|
1592 | |
---|
1593 | @ifset is-Ada |
---|
1594 | @end ifset |
---|
1595 | |
---|
1596 | @subheading STATUS CODES: |
---|
1597 | |
---|
1598 | @table @b |
---|
1599 | @item EACCES |
---|
1600 | Search permission is denied for a directory in a file's path prefix |
---|
1601 | |
---|
1602 | @item ENAMETOOLONG |
---|
1603 | Length of a filename string exceeds PATH_MAX and _POSIX_NO_TRUNC is in |
---|
1604 | effect. |
---|
1605 | |
---|
1606 | @item ENOENT |
---|
1607 | A file or directory does not exist. |
---|
1608 | |
---|
1609 | @item ENOTDIR |
---|
1610 | A component of the specified pathname was not a directory when a directory |
---|
1611 | was expected. |
---|
1612 | |
---|
1613 | @item EPERM |
---|
1614 | Operation is not permitted. Process does not have the appropriate priviledges |
---|
1615 | or permissions to perform the requested operations. |
---|
1616 | |
---|
1617 | @item EROFS |
---|
1618 | Read-only file system. |
---|
1619 | |
---|
1620 | @end table |
---|
1621 | |
---|
1622 | @subheading DESCRIPTION: |
---|
1623 | |
---|
1624 | Set the file permission bits, the set user ID bit, and the set group ID bit |
---|
1625 | for the file named by @code{path} to @code{mode}. If the effective user ID |
---|
1626 | does not match the owner of the file and the calling process does not have |
---|
1627 | the appropriate privileges, @code{chmod()} returns -1 and sets @code{errno} to |
---|
1628 | @code{EPERM}. |
---|
1629 | |
---|
1630 | @subheading NOTES: |
---|
1631 | |
---|
1632 | NONE |
---|
1633 | |
---|
1634 | @c |
---|
1635 | @c |
---|
1636 | @c |
---|
1637 | @page |
---|
1638 | @subsection fchmod - Changes permissions of a file |
---|
1639 | |
---|
1640 | @findex fchmod |
---|
1641 | @cindex changes permissions of a file |
---|
1642 | |
---|
1643 | @subheading CALLING SEQUENCE: |
---|
1644 | |
---|
1645 | @ifset is-C |
---|
1646 | @example |
---|
1647 | #include <sys/types.h> |
---|
1648 | #include <sys/stat.h> |
---|
1649 | |
---|
1650 | int fchmod( |
---|
1651 | int fildes, |
---|
1652 | mode_t mode |
---|
1653 | ); |
---|
1654 | @end example |
---|
1655 | @end ifset |
---|
1656 | |
---|
1657 | @ifset is-Ada |
---|
1658 | @end ifset |
---|
1659 | |
---|
1660 | @subheading STATUS CODES: |
---|
1661 | |
---|
1662 | @table @b |
---|
1663 | @item EACCES |
---|
1664 | Search permission is denied for a directory in a file's path prefix. |
---|
1665 | |
---|
1666 | @item EBADF |
---|
1667 | The descriptor is not valid. |
---|
1668 | |
---|
1669 | @item EFAULT |
---|
1670 | @code{path} points outside your accessible address space. |
---|
1671 | |
---|
1672 | @item EIO |
---|
1673 | A low-level I/o error occurred while modifying the inode. |
---|
1674 | |
---|
1675 | @item ELOOP |
---|
1676 | @code{path} contains a circular reference |
---|
1677 | |
---|
1678 | @item ENAMETOOLONG |
---|
1679 | Length of a filename string exceeds PATH_MAX and _POSIX_NO_TRUNC is |
---|
1680 | in effect. |
---|
1681 | |
---|
1682 | @item ENOENT |
---|
1683 | A file or directory does no exist. |
---|
1684 | |
---|
1685 | @item ENOMEM |
---|
1686 | Insufficient kernel memory was avaliable. |
---|
1687 | |
---|
1688 | @item ENOTDIR |
---|
1689 | A component of the specified pathname was not a directory when a |
---|
1690 | directory was expected. |
---|
1691 | |
---|
1692 | @item EPERM |
---|
1693 | The effective UID does not match the owner of the file, and is not |
---|
1694 | zero |
---|
1695 | |
---|
1696 | @item EROFS |
---|
1697 | Read-only file system |
---|
1698 | @end table |
---|
1699 | |
---|
1700 | @subheading DESCRIPTION: |
---|
1701 | |
---|
1702 | The mode of the file given by @code{path} or referenced by |
---|
1703 | @code{filedes} is changed. |
---|
1704 | |
---|
1705 | @subheading NOTES: |
---|
1706 | |
---|
1707 | NONE |
---|
1708 | |
---|
1709 | @c |
---|
1710 | @c |
---|
1711 | @c |
---|
1712 | @page |
---|
1713 | @subsection getdents - Get directory entries |
---|
1714 | |
---|
1715 | @findex getdents |
---|
1716 | @cindex get directory entries |
---|
1717 | |
---|
1718 | @subheading CALLING SEQUENCE: |
---|
1719 | |
---|
1720 | @ifset is-C |
---|
1721 | @example |
---|
1722 | #include <unistd.h> |
---|
1723 | #include <linux/dirent.h> |
---|
1724 | #include <linux/unistd.h> |
---|
1725 | |
---|
1726 | long getdents( |
---|
1727 | int dd_fd, |
---|
1728 | char *dd_buf, |
---|
1729 | int dd_len |
---|
1730 | ); |
---|
1731 | @end example |
---|
1732 | @end ifset |
---|
1733 | |
---|
1734 | @ifset is-Ada |
---|
1735 | @end ifset |
---|
1736 | |
---|
1737 | @subheading STATUS CODES: |
---|
1738 | |
---|
1739 | A successful call to @code{getdents} returns th the number of bytes read. |
---|
1740 | On end of directory, 0 is returned. When an error occurs, -1 is returned, |
---|
1741 | and @code{errno} is set appropriately. |
---|
1742 | |
---|
1743 | @table @b |
---|
1744 | @item EBADF |
---|
1745 | Invalid file descriptor @code{fd}. |
---|
1746 | |
---|
1747 | @item EFAULT |
---|
1748 | Argument points outside the calling process's address space. |
---|
1749 | |
---|
1750 | @item EINVAL |
---|
1751 | Result buffer is too small. |
---|
1752 | |
---|
1753 | @item ENOENT |
---|
1754 | No such directory. |
---|
1755 | |
---|
1756 | @item ENOTDIR |
---|
1757 | File descriptor does not refer to a directory. |
---|
1758 | |
---|
1759 | @end table |
---|
1760 | |
---|
1761 | @subheading DESCRIPTION: |
---|
1762 | |
---|
1763 | @code{getdents} reads several @code{dirent} structures from the directory |
---|
1764 | pointed by @code{fd} into the memory area pointed to by @code{dirp}. The |
---|
1765 | parameter @code{count} is the size of the memory area. |
---|
1766 | |
---|
1767 | @subheading NOTES: |
---|
1768 | |
---|
1769 | NONE |
---|
1770 | |
---|
1771 | @c |
---|
1772 | @c |
---|
1773 | @c |
---|
1774 | @page |
---|
1775 | @subsection chown - Changes the owner and/or group of a file. |
---|
1776 | |
---|
1777 | @findex chown |
---|
1778 | @cindex changes the owner and/or group of a file. |
---|
1779 | |
---|
1780 | @subheading CALLING SEQUENCE: |
---|
1781 | |
---|
1782 | @ifset is-C |
---|
1783 | @example |
---|
1784 | #include <sys/types.h> |
---|
1785 | #include <unistd.h> |
---|
1786 | |
---|
1787 | int chown( |
---|
1788 | const char *path, |
---|
1789 | uid_t owner, |
---|
1790 | gid_t group |
---|
1791 | ); |
---|
1792 | @end example |
---|
1793 | @end ifset |
---|
1794 | |
---|
1795 | @ifset is-Ada |
---|
1796 | @end ifset |
---|
1797 | |
---|
1798 | @subheading STATUS CODES: |
---|
1799 | |
---|
1800 | @table @b |
---|
1801 | @item EACCES |
---|
1802 | Search permission is denied for a directory in a file's path prefix |
---|
1803 | |
---|
1804 | @item EINVAL |
---|
1805 | Invalid argument |
---|
1806 | |
---|
1807 | @item ENAMETOOLONG |
---|
1808 | Length of a filename string exceeds PATH_MAX and _POSIX_NO_TRUNC is in |
---|
1809 | effect. |
---|
1810 | |
---|
1811 | @item ENOENT |
---|
1812 | A file or directory does not exist. |
---|
1813 | |
---|
1814 | @item ENOTDIR |
---|
1815 | A component of the specified pathname was not a directory when a directory |
---|
1816 | was expected. |
---|
1817 | |
---|
1818 | @item EPERM |
---|
1819 | Operation is not permitted. Process does not have the appropriate priviledges |
---|
1820 | or permissions to perform the requested operations. |
---|
1821 | |
---|
1822 | @item EROFS |
---|
1823 | Read-only file system. |
---|
1824 | |
---|
1825 | @end table |
---|
1826 | |
---|
1827 | @subheading DESCRIPTION: |
---|
1828 | |
---|
1829 | The user ID and group ID of the file named by @code{path} are set to |
---|
1830 | @code{owner} and @code{path}, respectively. |
---|
1831 | |
---|
1832 | For regular files, the set group ID (S_ISGID) and set user ID (S_ISUID) |
---|
1833 | bits are cleared. |
---|
1834 | |
---|
1835 | Some systems consider it a security violation to allow the owner of a file to |
---|
1836 | be changed, If users are billed for disk space usage, loaning a file to |
---|
1837 | another user could result in incorrect billing. The @code{chown()} function |
---|
1838 | may be restricted to privileged users for some or all files. The group ID can |
---|
1839 | still be changed to one of the supplementary group IDs. |
---|
1840 | |
---|
1841 | @subheading NOTES: |
---|
1842 | |
---|
1843 | This function may be restricted for some file. The @code{pathconf} function |
---|
1844 | can be used to test the @code{_PC_CHOWN_RESTRICTED} flag. |
---|
1845 | |
---|
1846 | |
---|
1847 | |
---|
1848 | @c |
---|
1849 | @c |
---|
1850 | @c |
---|
1851 | @page |
---|
1852 | @subsection utime - Change access and/or modification times of an inode |
---|
1853 | |
---|
1854 | @findex utime |
---|
1855 | @cindex change access and/or modification times of an inode |
---|
1856 | |
---|
1857 | @subheading CALLING SEQUENCE: |
---|
1858 | |
---|
1859 | @ifset is-C |
---|
1860 | @example |
---|
1861 | #include <sys/types.h> |
---|
1862 | |
---|
1863 | int utime( |
---|
1864 | const char *filename, |
---|
1865 | struct utimbuf *buf |
---|
1866 | ); |
---|
1867 | @end example |
---|
1868 | @end ifset |
---|
1869 | |
---|
1870 | @ifset is-Ada |
---|
1871 | @end ifset |
---|
1872 | |
---|
1873 | @subheading STATUS CODES: |
---|
1874 | |
---|
1875 | @table @b |
---|
1876 | @item EACCES |
---|
1877 | Permission to write the file is denied |
---|
1878 | |
---|
1879 | @item ENOENT |
---|
1880 | @code{Filename} does not exist |
---|
1881 | |
---|
1882 | @end table |
---|
1883 | |
---|
1884 | @subheading DESCRIPTION: |
---|
1885 | |
---|
1886 | @code{Utime} changes the access and modification times of the inode |
---|
1887 | specified by @code{filename} to the @code{actime} and @code{modtime} |
---|
1888 | fields of @code{buf} respectively. If @code{buf} is NULL, then the |
---|
1889 | access and modification times of the file are set to the current time. |
---|
1890 | |
---|
1891 | @subheading NOTES: |
---|
1892 | |
---|
1893 | NONE |
---|
1894 | |
---|
1895 | @c |
---|
1896 | @c |
---|
1897 | @c |
---|
1898 | @page |
---|
1899 | @subsection ftruncate - truncate a file to a specified length |
---|
1900 | |
---|
1901 | @findex ftruncate |
---|
1902 | @cindex truncate a file to a specified length |
---|
1903 | |
---|
1904 | @subheading CALLING SEQUENCE: |
---|
1905 | |
---|
1906 | @ifset is-C |
---|
1907 | @example |
---|
1908 | #include <unistd.h> |
---|
1909 | |
---|
1910 | int ftrunctate( |
---|
1911 | int fd, |
---|
1912 | size_t length |
---|
1913 | ); |
---|
1914 | @end example |
---|
1915 | @end ifset |
---|
1916 | |
---|
1917 | @ifset is-Ada |
---|
1918 | @end ifset |
---|
1919 | |
---|
1920 | @subheading STATUS CODES: |
---|
1921 | |
---|
1922 | @table @b |
---|
1923 | @item ENOTDIR |
---|
1924 | A component of the path prefix is not a directory. |
---|
1925 | |
---|
1926 | @item EINVAL |
---|
1927 | The pathname contains a character with the high-order bit set. |
---|
1928 | |
---|
1929 | @item ENAMETOOLONG |
---|
1930 | A component of a pathname exceeded 255 characters, or an entire |
---|
1931 | path name exceeded 1023 characters. |
---|
1932 | |
---|
1933 | @item ENOENT |
---|
1934 | The named file does not exist. |
---|
1935 | |
---|
1936 | @item EACCES |
---|
1937 | The named file is not writable by the user. |
---|
1938 | |
---|
1939 | @item EACCES |
---|
1940 | Search permission is denied for a component of the path prefix. |
---|
1941 | |
---|
1942 | @item ELOOP |
---|
1943 | Too many symbolic links were encountered in translating the |
---|
1944 | pathname |
---|
1945 | |
---|
1946 | @item EISDIR |
---|
1947 | The named file is a directory. |
---|
1948 | |
---|
1949 | @item EROFS |
---|
1950 | The named file resides on a read-only file system |
---|
1951 | |
---|
1952 | @item ETXTBSY |
---|
1953 | The file is a pure procedure (shared text) file that is being |
---|
1954 | executed |
---|
1955 | |
---|
1956 | @item EIO |
---|
1957 | An I/O error occurred updating the inode. |
---|
1958 | |
---|
1959 | @item EFAULT |
---|
1960 | @code{Path} points outside the process's allocated address space. |
---|
1961 | |
---|
1962 | @item EBADF |
---|
1963 | The @code{fd} is not a valid descriptor. |
---|
1964 | |
---|
1965 | @end table |
---|
1966 | |
---|
1967 | @subheading DESCRIPTION: |
---|
1968 | |
---|
1969 | @code{truncate()} causes the file named by @code{path} or referenced by |
---|
1970 | @code{fd} to be truncated to at most @code{length} bytes in size. If the |
---|
1971 | file previously was larger than this size, the extra data is lost. With |
---|
1972 | @code{ftruncate()}, the file must be open for writing. |
---|
1973 | |
---|
1974 | @subheading NOTES: |
---|
1975 | |
---|
1976 | NONE |
---|
1977 | |
---|
1978 | @c |
---|
1979 | @c |
---|
1980 | @c |
---|
1981 | @page |
---|
1982 | @subsection truncate - truncate a file to a specified length |
---|
1983 | |
---|
1984 | @findex truncate |
---|
1985 | @cindex truncate a file to a specified length |
---|
1986 | |
---|
1987 | @subheading CALLING SEQUENCE: |
---|
1988 | |
---|
1989 | @ifset is-C |
---|
1990 | @example |
---|
1991 | #include <unistd.h> |
---|
1992 | |
---|
1993 | int trunctate( |
---|
1994 | const char *path, |
---|
1995 | size_t length |
---|
1996 | ); |
---|
1997 | @end example |
---|
1998 | @end ifset |
---|
1999 | |
---|
2000 | @ifset is-Ada |
---|
2001 | @end ifset |
---|
2002 | |
---|
2003 | @subheading STATUS CODES: |
---|
2004 | |
---|
2005 | @table @b |
---|
2006 | @item ENOTDIR |
---|
2007 | A component of the path prefix is not a directory. |
---|
2008 | |
---|
2009 | @item EINVAL |
---|
2010 | The pathname contains a character with the high-order bit set. |
---|
2011 | |
---|
2012 | @item ENAMETOOLONG |
---|
2013 | A component of a pathname exceeded 255 characters, or an entire |
---|
2014 | path name exceeded 1023 characters. |
---|
2015 | |
---|
2016 | @item ENOENT |
---|
2017 | The named file does not exist. |
---|
2018 | |
---|
2019 | @item EACCES |
---|
2020 | The named file is not writable by the user. |
---|
2021 | |
---|
2022 | @item EACCES |
---|
2023 | Search permission is denied for a component of the path prefix. |
---|
2024 | |
---|
2025 | @item ELOOP |
---|
2026 | Too many symbolic links were encountered in translating the |
---|
2027 | pathname |
---|
2028 | |
---|
2029 | @item EISDIR |
---|
2030 | The named file is a directory. |
---|
2031 | |
---|
2032 | @item EROFS |
---|
2033 | The named file resides on a read-only file system |
---|
2034 | |
---|
2035 | @item ETXTBSY |
---|
2036 | The file is a pure procedure (shared text) file that is being |
---|
2037 | executed |
---|
2038 | |
---|
2039 | @item EIO |
---|
2040 | An I/O error occurred updating the inode. |
---|
2041 | |
---|
2042 | @item EFAULT |
---|
2043 | @code{Path} points outside the process's allocated address space. |
---|
2044 | |
---|
2045 | @item EBADF |
---|
2046 | The @code{fd} is not a valid descriptor. |
---|
2047 | |
---|
2048 | @end table |
---|
2049 | |
---|
2050 | @subheading DESCRIPTION: |
---|
2051 | |
---|
2052 | @code{truncate()} causes the file named by @code{path} or referenced by |
---|
2053 | @code{fd} to be truncated to at most @code{length} bytes in size. If the |
---|
2054 | file previously was larger than this size, the extra data is lost. With |
---|
2055 | @code{ftruncate()}, the file must be open for writing. |
---|
2056 | |
---|
2057 | @subheading NOTES: |
---|
2058 | |
---|
2059 | NONE |
---|
2060 | |
---|
2061 | @c |
---|
2062 | @c |
---|
2063 | @c |
---|
2064 | @page |
---|
2065 | @subsection pathconf - Gets configuration values for files |
---|
2066 | |
---|
2067 | @findex pathconf |
---|
2068 | @cindex gets configuration values for files |
---|
2069 | |
---|
2070 | @subheading CALLING SEQUENCE: |
---|
2071 | |
---|
2072 | @ifset is-C |
---|
2073 | @example |
---|
2074 | #include <unistd.h> |
---|
2075 | |
---|
2076 | int pathconf( |
---|
2077 | const char *path, |
---|
2078 | int name |
---|
2079 | ); |
---|
2080 | @end example |
---|
2081 | @end ifset |
---|
2082 | |
---|
2083 | @ifset is-Ada |
---|
2084 | @end ifset |
---|
2085 | |
---|
2086 | @subheading STATUS CODES: |
---|
2087 | |
---|
2088 | @table @b |
---|
2089 | @item EINVAL |
---|
2090 | Invalid argument |
---|
2091 | |
---|
2092 | @item EACCES |
---|
2093 | Permission to write the file is denied |
---|
2094 | |
---|
2095 | @item ENAMETOOLONG |
---|
2096 | Length of a filename string exceeds PATH_MAX and _POSIX_NO_TRUNC |
---|
2097 | is in effect. |
---|
2098 | |
---|
2099 | @item ENOENT |
---|
2100 | A file or directory does not exist |
---|
2101 | |
---|
2102 | @item ENOTDIR |
---|
2103 | A component of the specified @code{path} was not a directory whan a |
---|
2104 | directory was expected. |
---|
2105 | |
---|
2106 | @end table |
---|
2107 | |
---|
2108 | @subheading DESCRIPTION: |
---|
2109 | |
---|
2110 | @code{pathconf()} gets a value for the configuration option @code{name} |
---|
2111 | for the open file descriptor @code{filedes}. |
---|
2112 | |
---|
2113 | The possible values for @code{name} are: |
---|
2114 | |
---|
2115 | @table @b |
---|
2116 | @item _PC_LINK_MAX |
---|
2117 | returns the maximum number of links to the file. If @code{filedes} or |
---|
2118 | @code{path} refer to a directory, then the value applies to the whole |
---|
2119 | directory. The corresponding macro is @code{_POSIX_LINK_MAX}. |
---|
2120 | |
---|
2121 | @item _PC_MAX_CANON |
---|
2122 | returns the maximum length of a formatted input line, where @code{filedes} |
---|
2123 | or @code{path} must refer to a terminal. The corresponding macro is |
---|
2124 | @code{_POSIX_MAX_CANON}. |
---|
2125 | |
---|
2126 | @item _PC_MAX_INPUT |
---|
2127 | returns the maximum length of an input line, where @code{filedes} or |
---|
2128 | @code{path} must refer to a terminal. The corresponding macro is |
---|
2129 | @code{_POSIX_MAX_INPUT}. |
---|
2130 | |
---|
2131 | @item _PC_NAME_MAX |
---|
2132 | returns the maximum length of a filename in the directory @code{path} or |
---|
2133 | @code{filedes}. The process is allowed to create. The corresponding macro |
---|
2134 | is @code{_POSIX_NAME_MAX}. |
---|
2135 | |
---|
2136 | @item _PC_PATH_MAX |
---|
2137 | returns the maximum length of a relative pathname when @code{path} or |
---|
2138 | @code{filedes} is the current working directory. The corresponding macro |
---|
2139 | is @code{_POSIX_PATH_MAX}. |
---|
2140 | |
---|
2141 | @item _PC_PIPE_BUF |
---|
2142 | returns the size of the pipe buffer, where @code{filedes} must refer to a |
---|
2143 | pipe or FIFO and @code{path} must refer to a FIFO. The corresponding macro |
---|
2144 | is @code{_POSIX_PIPE_BUF}. |
---|
2145 | |
---|
2146 | @item _PC_CHOWN_RESTRICTED |
---|
2147 | returns nonzero if the chown(2) call may not be used on this file. If |
---|
2148 | @code{filedes} or @code{path} refer to a directory, then this applies to all |
---|
2149 | files in that directory. The corresponding macro is |
---|
2150 | @code{_POSIX_CHOWN_RESTRICTED}. |
---|
2151 | |
---|
2152 | @end table |
---|
2153 | |
---|
2154 | @subheading NOTES: |
---|
2155 | |
---|
2156 | Files with name lengths longer than the value returned for @code{name} equal |
---|
2157 | @code{_PC_NAME_MAX} may exist in the given directory. |
---|
2158 | |
---|
2159 | @c |
---|
2160 | @c |
---|
2161 | @c |
---|
2162 | @page |
---|
2163 | @subsection fpathconf - Gets configuration values for files |
---|
2164 | |
---|
2165 | @findex fpathconf |
---|
2166 | @cindex gets configuration values for files |
---|
2167 | |
---|
2168 | @subheading CALLING SEQUENCE: |
---|
2169 | |
---|
2170 | @ifset is-C |
---|
2171 | @example |
---|
2172 | #include <unistd.h> |
---|
2173 | |
---|
2174 | int fpathconf( |
---|
2175 | int filedes, |
---|
2176 | int name |
---|
2177 | ); |
---|
2178 | @end example |
---|
2179 | @end ifset |
---|
2180 | |
---|
2181 | @ifset is-Ada |
---|
2182 | @end ifset |
---|
2183 | |
---|
2184 | @subheading STATUS CODES: |
---|
2185 | |
---|
2186 | @table @b |
---|
2187 | @item EINVAL |
---|
2188 | Invalid argument |
---|
2189 | |
---|
2190 | @item EACCES |
---|
2191 | Permission to write the file is denied |
---|
2192 | @item ENAMETOOLONG |
---|
2193 | |
---|
2194 | Length of a filename string exceeds PATH_MAX and _POSIX_NO_TRUNC |
---|
2195 | is in effect. |
---|
2196 | |
---|
2197 | @item ENOENT |
---|
2198 | A file or directory does not exist |
---|
2199 | |
---|
2200 | @item ENOTDIR |
---|
2201 | A component of the specified @code{path} was not a directory whan a |
---|
2202 | directory was expected. |
---|
2203 | |
---|
2204 | @end table |
---|
2205 | |
---|
2206 | |
---|
2207 | @subheading DESCRIPTION: |
---|
2208 | |
---|
2209 | @code{pathconf()} gets a value for the configuration option @code{name} |
---|
2210 | for the open file descriptor @code{filedes}. |
---|
2211 | |
---|
2212 | The possible values for name are: |
---|
2213 | |
---|
2214 | @table @b |
---|
2215 | @item _PC_LINK_MAX |
---|
2216 | returns the maximum number of links to the file. If @code{filedes} or |
---|
2217 | @code{path} refer to a directory, then the value applies to the whole |
---|
2218 | directory. The corresponding macro is _POSIX_LINK_MAX. |
---|
2219 | |
---|
2220 | @item _PC_MAX_CANON |
---|
2221 | returns the maximum length of a formatted input line, where @code{filedes} |
---|
2222 | or @code{path} must refer to a terminal. The corresponding macro is |
---|
2223 | @code{_POSIX_MAX_CANON}. |
---|
2224 | |
---|
2225 | @item _PC_MAX_INPUT |
---|
2226 | returns the maximum length of an input line, where @code{filedes} or |
---|
2227 | @code{path} must refer to a terminal. The corresponding macro is |
---|
2228 | @code{_POSIX_MAX_INPUT}. |
---|
2229 | |
---|
2230 | @item _PC_NAME_MAX |
---|
2231 | returns the maximum length of a filename in the directory @code{path} or |
---|
2232 | @code{filedes}. The process is allowed to create. The corresponding macro |
---|
2233 | is @code{_POSIX_NAME_MAX}. |
---|
2234 | |
---|
2235 | @item _PC_PATH_MAX |
---|
2236 | returns the maximum length of a relative pathname when @code{path} or |
---|
2237 | @code{filedes} is the current working directory. The corresponding macro |
---|
2238 | is @code{_POSIX_PATH_MAX}. |
---|
2239 | |
---|
2240 | @item _PC_PIPE_BUF |
---|
2241 | returns the size of the pipe buffer, where @code{filedes} must refer to a |
---|
2242 | pipe or FIFO and @code{path} must refer to a FIFO. The corresponding macro |
---|
2243 | is @code{_POSIX_PIPE_BUF}. |
---|
2244 | |
---|
2245 | @item _PC_CHOWN_RESTRICTED |
---|
2246 | returns nonzero if the @code{chown()} call may not be used on this file. If |
---|
2247 | @code{filedes} or @code{path} refer to a directory, then this applies to all |
---|
2248 | files in that directory. The corresponding macro is |
---|
2249 | @code{_POSIX_CHOWN_RESTRICTED}. |
---|
2250 | |
---|
2251 | @end table |
---|
2252 | |
---|
2253 | @subheading NOTES: |
---|
2254 | |
---|
2255 | NONE |
---|
2256 | |
---|
2257 | @c |
---|
2258 | @c |
---|
2259 | @c |
---|
2260 | @page |
---|
2261 | @subsection mknod - create a directory |
---|
2262 | |
---|
2263 | @findex mknod |
---|
2264 | @cindex create a directory |
---|
2265 | |
---|
2266 | @subheading CALLING SEQUENCE: |
---|
2267 | |
---|
2268 | @ifset is-C |
---|
2269 | @example |
---|
2270 | #include <unistd.h> |
---|
2271 | #include <fcntl.h> |
---|
2272 | #include <sys/types.h> |
---|
2273 | #include <sys/stat.h> |
---|
2274 | |
---|
2275 | long mknod( |
---|
2276 | const char *pathname, |
---|
2277 | mode_t mode, |
---|
2278 | dev_t dev |
---|
2279 | ); |
---|
2280 | @end example |
---|
2281 | @end ifset |
---|
2282 | |
---|
2283 | @ifset is-Ada |
---|
2284 | @end ifset |
---|
2285 | |
---|
2286 | @subheading STATUS CODES: |
---|
2287 | |
---|
2288 | @code{mknod} returns zero on success, or -1 if an error occurred (in which case, |
---|
2289 | errno is set appropriately). |
---|
2290 | |
---|
2291 | @table @b |
---|
2292 | @item ENAMETOOLONG |
---|
2293 | @code{pathname} was too long. |
---|
2294 | |
---|
2295 | @item ENOENT |
---|
2296 | A directory component in @code{pathname} does not exist or is a dangling symbolic |
---|
2297 | link. |
---|
2298 | |
---|
2299 | @item ENOTDIR |
---|
2300 | A component used in the directory @code{pathname} is not, in fact, a directory. |
---|
2301 | |
---|
2302 | @item ENOMEM |
---|
2303 | Insufficient kernel memory was available |
---|
2304 | |
---|
2305 | @item EROFS |
---|
2306 | @code{pathname} refers to a file on a read-only filesystem. |
---|
2307 | |
---|
2308 | @item ELOOP |
---|
2309 | @code{pathname} contains a reference to a circular symbolic link, ie a symbolic |
---|
2310 | link whose expansion contains a reference to itself. |
---|
2311 | |
---|
2312 | @item ENOSPC |
---|
2313 | The device containing @code{pathname} has no room for the new node. |
---|
2314 | |
---|
2315 | @end table |
---|
2316 | |
---|
2317 | @subheading DESCRIPTION: |
---|
2318 | |
---|
2319 | @code{mknod} attempts to create a filesystem node (file, device special file or |
---|
2320 | named pipe) named @code{pathname}, specified by @code{mode} and @code{dev}. |
---|
2321 | |
---|
2322 | @code{mode} specifies both the permissions to use and the type of node to be created. |
---|
2323 | |
---|
2324 | It should be a combination (using bitwise OR) of one of the file types listed |
---|
2325 | below and the permissions for the new node. |
---|
2326 | |
---|
2327 | The permissions are modified by the process's @code{umask} in the usual way: the |
---|
2328 | permissions of the created node are @code{(mode & ~umask)}. |
---|
2329 | |
---|
2330 | The file type should be one of @code{S_IFREG}, @code{S_IFCHR}, @code{S_IFBLK} and |
---|
2331 | @code{S_IFIFO} to specify a normal file (which will be created empty), character |
---|
2332 | special file, block special file or FIFO (named pipe), respectively, or zero, which |
---|
2333 | will create a normal file. |
---|
2334 | |
---|
2335 | If the file type is @code{S_IFCHR} or @code{S_IFBLK} then @code{dev} specifies the major |
---|
2336 | and minor numbers of the newly created device special file; otherwise it is ignored. |
---|
2337 | |
---|
2338 | The newly created node will be owned by the effective uid of the process. If the |
---|
2339 | directory containing the node has the set group id bit set, or if the filesystem |
---|
2340 | is mounted with BSD group semantics, the new node will inherit the group ownership |
---|
2341 | from its parent directory; otherwise it will be owned by the effective gid of the |
---|
2342 | process. |
---|
2343 | |
---|
2344 | |
---|
2345 | @subheading NOTES: |
---|
2346 | |
---|
2347 | NONE |
---|