* sysdeps/unix/sysv/linux/m68k/sysdep.h (INLINE_SYSCALL): Don't
[glibc.git] / libio / oldfileops.c
blob3d772fd4de58ffee3ca44eb50fbab7c1ad57bcff
1 /* Copyright (C) 1993,95,97,98,99,2000 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Written by Per Bothner <bothner@cygnus.com>.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA.
20 As a special exception, if you link the code in this file with
21 files compiled with a GNU compiler to produce an executable,
22 that does not cause the resulting executable to be covered by
23 the GNU Lesser General Public License. This exception does not
24 however invalidate any other reasons why the executable file
25 might be covered by the GNU Lesser General Public License.
26 This exception applies to code released by its copyright holders
27 in files containing the exception. */
29 /* This is a compatibility file. If we don't build the libc with
30 versioning don't compile this file. */
31 #include <shlib-compat.h>
32 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
34 #ifndef _POSIX_SOURCE
35 # define _POSIX_SOURCE
36 #endif
37 #define _IO_USE_OLD_IO_FILE
38 #include "libioP.h"
39 #include <fcntl.h>
40 #include <sys/types.h>
41 #include <sys/stat.h>
42 #include <string.h>
43 #include <errno.h>
44 #ifdef __STDC__
45 #include <stdlib.h>
46 #endif
47 #ifndef errno
48 extern int errno;
49 #endif
50 #ifndef __set_errno
51 # define __set_errno(Val) errno = (Val)
52 #endif
55 #ifdef _LIBC
56 # define open(Name, Flags, Prot) __open (Name, Flags, Prot)
57 # define close(FD) __close (FD)
58 # define lseek(FD, Offset, Whence) __lseek (FD, Offset, Whence)
59 # define read(FD, Buf, NBytes) __read (FD, Buf, NBytes)
60 # define write(FD, Buf, NBytes) __write (FD, Buf, NBytes)
61 #endif
63 /* An fstream can be in at most one of put mode, get mode, or putback mode.
64 Putback mode is a variant of get mode.
66 In a filebuf, there is only one current position, instead of two
67 separate get and put pointers. In get mode, the current position
68 is that of gptr(); in put mode that of pptr().
70 The position in the buffer that corresponds to the position
71 in external file system is normally _IO_read_end, except in putback
72 mode, when it is _IO_save_end.
73 If the field _fb._offset is >= 0, it gives the offset in
74 the file as a whole corresponding to eGptr(). (?)
76 PUT MODE:
77 If a filebuf is in put mode, then all of _IO_read_ptr, _IO_read_end,
78 and _IO_read_base are equal to each other. These are usually equal
79 to _IO_buf_base, though not necessarily if we have switched from
80 get mode to put mode. (The reason is to maintain the invariant
81 that _IO_read_end corresponds to the external file position.)
82 _IO_write_base is non-NULL and usually equal to _IO_base_base.
83 We also have _IO_write_end == _IO_buf_end, but only in fully buffered mode.
84 The un-flushed character are those between _IO_write_base and _IO_write_ptr.
86 GET MODE:
87 If a filebuf is in get or putback mode, eback() != egptr().
88 In get mode, the unread characters are between gptr() and egptr().
89 The OS file position corresponds to that of egptr().
91 PUTBACK MODE:
92 Putback mode is used to remember "excess" characters that have
93 been sputbackc'd in a separate putback buffer.
94 In putback mode, the get buffer points to the special putback buffer.
95 The unread characters are the characters between gptr() and egptr()
96 in the putback buffer, as well as the area between save_gptr()
97 and save_egptr(), which point into the original reserve buffer.
98 (The pointers save_gptr() and save_egptr() are the values
99 of gptr() and egptr() at the time putback mode was entered.)
100 The OS position corresponds to that of save_egptr().
102 LINE BUFFERED OUTPUT:
103 During line buffered output, _IO_write_base==base() && epptr()==base().
104 However, ptr() may be anywhere between base() and ebuf().
105 This forces a call to filebuf::overflow(int C) on every put.
106 If there is more space in the buffer, and C is not a '\n',
107 then C is inserted, and pptr() incremented.
109 UNBUFFERED STREAMS:
110 If a filebuf is unbuffered(), the _shortbuf[1] is used as the buffer.
113 #define CLOSED_FILEBUF_FLAGS \
114 (_IO_IS_FILEBUF+_IO_NO_READS+_IO_NO_WRITES+_IO_TIED_PUT_GET)
117 void
118 _IO_old_file_init (fp)
119 struct _IO_FILE_plus *fp;
121 /* POSIX.1 allows another file handle to be used to change the position
122 of our file descriptor. Hence we actually don't know the actual
123 position before we do the first fseek (and until a following fflush). */
124 fp->file._old_offset = _IO_pos_BAD;
125 fp->file._IO_file_flags |= CLOSED_FILEBUF_FLAGS;
127 _IO_link_in (fp);
128 fp->file._vtable_offset = ((int) sizeof (struct _IO_FILE)
129 - (int) sizeof (struct _IO_FILE_complete));
130 fp->file._fileno = -1;
134 _IO_old_file_close_it (fp)
135 _IO_FILE *fp;
137 int write_status, close_status;
138 if (!_IO_file_is_open (fp))
139 return EOF;
141 write_status = _IO_old_do_flush (fp);
143 _IO_unsave_markers(fp);
145 close_status = _IO_SYSCLOSE (fp);
147 /* Free buffer. */
148 _IO_setb (fp, NULL, NULL, 0);
149 _IO_setg (fp, NULL, NULL, NULL);
150 _IO_setp (fp, NULL, NULL);
152 _IO_un_link ((struct _IO_FILE_plus *) fp);
153 fp->_flags = _IO_MAGIC|CLOSED_FILEBUF_FLAGS;
154 fp->_fileno = -1;
155 fp->_old_offset = _IO_pos_BAD;
157 return close_status ? close_status : write_status;
160 void
161 _IO_old_file_finish (fp, dummy)
162 _IO_FILE *fp;
163 int dummy;
165 if (_IO_file_is_open (fp))
167 _IO_old_do_flush (fp);
168 if (!(fp->_flags & _IO_DELETE_DONT_CLOSE))
169 _IO_SYSCLOSE (fp);
171 _IO_default_finish (fp, 0);
174 _IO_FILE *
175 _IO_old_file_fopen (fp, filename, mode)
176 _IO_FILE *fp;
177 const char *filename;
178 const char *mode;
180 int oflags = 0, omode;
181 int read_write, fdesc;
182 int oprot = 0666;
183 if (_IO_file_is_open (fp))
184 return 0;
185 switch (*mode++)
187 case 'r':
188 omode = O_RDONLY;
189 read_write = _IO_NO_WRITES;
190 break;
191 case 'w':
192 omode = O_WRONLY;
193 oflags = O_CREAT|O_TRUNC;
194 read_write = _IO_NO_READS;
195 break;
196 case 'a':
197 omode = O_WRONLY;
198 oflags = O_CREAT|O_APPEND;
199 read_write = _IO_NO_READS|_IO_IS_APPENDING;
200 break;
201 default:
202 __set_errno (EINVAL);
203 return NULL;
205 if (mode[0] == '+' || (mode[0] == 'b' && mode[1] == '+'))
207 omode = O_RDWR;
208 read_write &= _IO_IS_APPENDING;
210 fdesc = open (filename, omode|oflags, oprot);
211 if (fdesc < 0)
212 return NULL;
213 fp->_fileno = fdesc;
214 _IO_mask_flags (fp, read_write,_IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
215 if (read_write & _IO_IS_APPENDING)
216 if (_IO_SEEKOFF (fp, (_IO_off_t)0, _IO_seek_end, _IOS_INPUT|_IOS_OUTPUT)
217 == _IO_pos_BAD && errno != ESPIPE)
218 return NULL;
219 _IO_link_in ((struct _IO_FILE_plus *) fp);
220 return fp;
223 _IO_FILE *
224 _IO_old_file_attach (fp, fd)
225 _IO_FILE *fp;
226 int fd;
228 if (_IO_file_is_open (fp))
229 return NULL;
230 fp->_fileno = fd;
231 fp->_flags &= ~(_IO_NO_READS+_IO_NO_WRITES);
232 fp->_flags |= _IO_DELETE_DONT_CLOSE;
233 /* Get the current position of the file. */
234 /* We have to do that since that may be junk. */
235 fp->_old_offset = _IO_pos_BAD;
236 if (_IO_SEEKOFF (fp, (_IO_off_t)0, _IO_seek_cur, _IOS_INPUT|_IOS_OUTPUT)
237 == _IO_pos_BAD && errno != ESPIPE)
238 return NULL;
239 return fp;
242 _IO_FILE *
243 _IO_old_file_setbuf (fp, p, len)
244 _IO_FILE *fp;
245 char *p;
246 _IO_ssize_t len;
248 if (_IO_default_setbuf (fp, p, len) == NULL)
249 return NULL;
251 fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_write_end
252 = fp->_IO_buf_base;
253 _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
255 return fp;
258 static int old_do_write __P ((_IO_FILE *, const char *, _IO_size_t));
260 /* Write TO_DO bytes from DATA to FP.
261 Then mark FP as having empty buffers. */
264 _IO_old_do_write (fp, data, to_do)
265 _IO_FILE *fp;
266 const char *data;
267 _IO_size_t to_do;
269 return (to_do == 0 || old_do_write (fp, data, to_do) == to_do)
270 ? 0 : EOF;
273 static
275 old_do_write (fp, data, to_do)
276 _IO_FILE *fp;
277 const char *data;
278 _IO_size_t to_do;
280 _IO_size_t count;
281 if (fp->_flags & _IO_IS_APPENDING)
282 /* On a system without a proper O_APPEND implementation,
283 you would need to sys_seek(0, SEEK_END) here, but is
284 is not needed nor desirable for Unix- or Posix-like systems.
285 Instead, just indicate that offset (before and after) is
286 unpredictable. */
287 fp->_old_offset = _IO_pos_BAD;
288 else if (fp->_IO_read_end != fp->_IO_write_base)
290 _IO_off_t new_pos
291 = _IO_SYSSEEK (fp, fp->_IO_write_base - fp->_IO_read_end, 1);
292 if (new_pos == _IO_pos_BAD)
293 return 0;
294 fp->_old_offset = new_pos;
296 count = _IO_SYSWRITE (fp, data, to_do);
297 if (fp->_cur_column && count)
298 fp->_cur_column = _IO_adjust_column (fp->_cur_column - 1, data, count) + 1;
299 _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
300 fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_buf_base;
301 fp->_IO_write_end = ((fp->_flags & (_IO_LINE_BUF+_IO_UNBUFFERED))
302 ? fp->_IO_buf_base : fp->_IO_buf_end);
303 return count;
307 _IO_old_file_underflow (fp)
308 _IO_FILE *fp;
310 _IO_ssize_t count;
311 #if 0
312 /* SysV does not make this test; take it out for compatibility */
313 if (fp->_flags & _IO_EOF_SEEN)
314 return (EOF);
315 #endif
317 if (fp->_flags & _IO_NO_READS)
319 fp->_flags |= _IO_ERR_SEEN;
320 __set_errno (EBADF);
321 return EOF;
323 if (fp->_IO_read_ptr < fp->_IO_read_end)
324 return *(unsigned char *) fp->_IO_read_ptr;
326 if (fp->_IO_buf_base == NULL)
328 /* Maybe we already have a push back pointer. */
329 if (fp->_IO_save_base != NULL)
331 free (fp->_IO_save_base);
332 fp->_flags &= ~_IO_IN_BACKUP;
334 _IO_doallocbuf (fp);
337 /* Flush all line buffered files before reading. */
338 /* FIXME This can/should be moved to genops ?? */
339 if (fp->_flags & (_IO_LINE_BUF|_IO_UNBUFFERED))
340 _IO_flush_all_linebuffered ();
342 _IO_switch_to_get_mode (fp);
344 /* This is very tricky. We have to adjust those
345 pointers before we call _IO_SYSREAD () since
346 we may longjump () out while waiting for
347 input. Those pointers may be screwed up. H.J. */
348 fp->_IO_read_base = fp->_IO_read_ptr = fp->_IO_buf_base;
349 fp->_IO_read_end = fp->_IO_buf_base;
350 fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_write_end
351 = fp->_IO_buf_base;
353 count = _IO_SYSREAD (fp, fp->_IO_buf_base,
354 fp->_IO_buf_end - fp->_IO_buf_base);
355 if (count <= 0)
357 if (count == 0)
358 fp->_flags |= _IO_EOF_SEEN;
359 else
360 fp->_flags |= _IO_ERR_SEEN, count = 0;
362 fp->_IO_read_end += count;
363 if (count == 0)
364 return EOF;
365 if (fp->_old_offset != _IO_pos_BAD)
366 _IO_pos_adjust (fp->_old_offset, count);
367 return *(unsigned char *) fp->_IO_read_ptr;
371 _IO_old_file_overflow (f, ch)
372 _IO_FILE *f;
373 int ch;
375 if (f->_flags & _IO_NO_WRITES) /* SET ERROR */
377 f->_flags |= _IO_ERR_SEEN;
378 __set_errno (EBADF);
379 return EOF;
381 /* If currently reading or no buffer allocated. */
382 if ((f->_flags & _IO_CURRENTLY_PUTTING) == 0)
384 /* Allocate a buffer if needed. */
385 if (f->_IO_write_base == 0)
387 _IO_doallocbuf (f);
388 _IO_setg (f, f->_IO_buf_base, f->_IO_buf_base, f->_IO_buf_base);
390 /* Otherwise must be currently reading.
391 If _IO_read_ptr (and hence also _IO_read_end) is at the buffer end,
392 logically slide the buffer forwards one block (by setting the
393 read pointers to all point at the beginning of the block). This
394 makes room for subsequent output.
395 Otherwise, set the read pointers to _IO_read_end (leaving that
396 alone, so it can continue to correspond to the external position). */
397 if (f->_IO_read_ptr == f->_IO_buf_end)
398 f->_IO_read_end = f->_IO_read_ptr = f->_IO_buf_base;
399 f->_IO_write_ptr = f->_IO_read_ptr;
400 f->_IO_write_base = f->_IO_write_ptr;
401 f->_IO_write_end = f->_IO_buf_end;
402 f->_IO_read_base = f->_IO_read_ptr = f->_IO_read_end;
404 if (f->_flags & (_IO_LINE_BUF+_IO_UNBUFFERED))
405 f->_IO_write_end = f->_IO_write_ptr;
406 f->_flags |= _IO_CURRENTLY_PUTTING;
408 if (ch == EOF)
409 return _IO_old_do_flush (f);
410 if (f->_IO_write_ptr == f->_IO_buf_end ) /* Buffer is really full */
411 if (_IO_old_do_flush (f) == EOF)
412 return EOF;
413 *f->_IO_write_ptr++ = ch;
414 if ((f->_flags & _IO_UNBUFFERED)
415 || ((f->_flags & _IO_LINE_BUF) && ch == '\n'))
416 if (_IO_old_do_flush (f) == EOF)
417 return EOF;
418 return (unsigned char) ch;
422 _IO_old_file_sync (fp)
423 _IO_FILE *fp;
425 _IO_ssize_t delta;
426 int retval = 0;
428 /* char* ptr = cur_ptr(); */
429 if (fp->_IO_write_ptr > fp->_IO_write_base)
430 if (_IO_old_do_flush(fp)) return EOF;
431 delta = fp->_IO_read_ptr - fp->_IO_read_end;
432 if (delta != 0)
434 #ifdef TODO
435 if (_IO_in_backup (fp))
436 delta -= eGptr () - Gbase ();
437 #endif
438 _IO_off_t new_pos = _IO_SYSSEEK (fp, delta, 1);
439 if (new_pos != (_IO_off_t) EOF)
440 fp->_IO_read_end = fp->_IO_read_ptr;
441 #ifdef ESPIPE
442 else if (errno == ESPIPE)
443 ; /* Ignore error from unseekable devices. */
444 #endif
445 else
446 retval = EOF;
448 if (retval != EOF)
449 fp->_old_offset = _IO_pos_BAD;
450 /* FIXME: Cleanup - can this be shared? */
451 /* setg(base(), ptr, ptr); */
452 return retval;
455 _IO_off64_t
456 _IO_old_file_seekoff (fp, offset, dir, mode)
457 _IO_FILE *fp;
458 _IO_off64_t offset;
459 int dir;
460 int mode;
462 _IO_off_t result;
463 _IO_off64_t delta, new_offset;
464 long count;
465 /* POSIX.1 8.2.3.7 says that after a call the fflush() the file
466 offset of the underlying file must be exact. */
467 int must_be_exact = (fp->_IO_read_base == fp->_IO_read_end
468 && fp->_IO_write_base == fp->_IO_write_ptr);
470 if (mode == 0)
471 dir = _IO_seek_cur, offset = 0; /* Don't move any pointers. */
473 /* Flush unwritten characters.
474 (This may do an unneeded write if we seek within the buffer.
475 But to be able to switch to reading, we would need to set
476 egptr to ptr. That can't be done in the current design,
477 which assumes file_ptr() is eGptr. Anyway, since we probably
478 end up flushing when we close(), it doesn't make much difference.)
479 FIXME: simulate mem-papped files. */
481 if (fp->_IO_write_ptr > fp->_IO_write_base || _IO_in_put_mode (fp))
482 if (_IO_switch_to_get_mode (fp))
483 return EOF;
485 if (fp->_IO_buf_base == NULL)
487 /* It could be that we already have a pushback buffer. */
488 if (fp->_IO_read_base != NULL)
490 free (fp->_IO_read_base);
491 fp->_flags &= ~_IO_IN_BACKUP;
493 _IO_doallocbuf (fp);
494 _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
495 _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
498 switch (dir)
500 case _IO_seek_cur:
501 /* Adjust for read-ahead (bytes is buffer). */
502 offset -= fp->_IO_read_end - fp->_IO_read_ptr;
503 if (fp->_old_offset == _IO_pos_BAD)
504 goto dumb;
505 /* Make offset absolute, assuming current pointer is file_ptr(). */
506 offset += fp->_old_offset;
508 dir = _IO_seek_set;
509 break;
510 case _IO_seek_set:
511 break;
512 case _IO_seek_end:
514 struct _G_stat64 st;
515 if (_IO_SYSSTAT (fp, &st) == 0 && S_ISREG (st.st_mode))
517 offset += st.st_size;
518 dir = _IO_seek_set;
520 else
521 goto dumb;
524 /* At this point, dir==_IO_seek_set. */
526 /* If we are only interested in the current position we've found it now. */
527 if (mode == 0)
528 return offset;
530 /* If destination is within current buffer, optimize: */
531 if (fp->_old_offset != _IO_pos_BAD && fp->_IO_read_base != NULL
532 && !_IO_in_backup (fp))
534 /* Offset relative to start of main get area. */
535 _IO_off_t rel_offset = (offset - fp->_old_offset
536 + (fp->_IO_read_end - fp->_IO_read_base));
537 if (rel_offset >= 0)
539 #if 0
540 if (_IO_in_backup (fp))
541 _IO_switch_to_main_get_area (fp);
542 #endif
543 if (rel_offset <= fp->_IO_read_end - fp->_IO_read_base)
545 _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + rel_offset,
546 fp->_IO_read_end);
547 _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
549 _IO_mask_flags (fp, 0, _IO_EOF_SEEN);
550 goto resync;
553 #ifdef TODO
554 /* If we have streammarkers, seek forward by reading ahead. */
555 if (_IO_have_markers (fp))
557 int to_skip = rel_offset
558 - (fp->_IO_read_ptr - fp->_IO_read_base);
559 if (ignore (to_skip) != to_skip)
560 goto dumb;
561 _IO_mask_flags (fp, 0, _IO_EOF_SEEN);
562 goto resync;
564 #endif
566 #ifdef TODO
567 if (rel_offset < 0 && rel_offset >= Bbase () - Bptr ())
569 if (!_IO_in_backup (fp))
570 _IO_switch_to_backup_area (fp);
571 gbump (fp->_IO_read_end + rel_offset - fp->_IO_read_ptr);
572 _IO_mask_flags (fp, 0, _IO_EOF_SEEN);
573 goto resync;
575 #endif
578 #ifdef TODO
579 _IO_unsave_markers (fp);
580 #endif
582 if (fp->_flags & _IO_NO_READS)
583 goto dumb;
585 /* Try to seek to a block boundary, to improve kernel page management. */
586 new_offset = offset & ~(fp->_IO_buf_end - fp->_IO_buf_base - 1);
587 delta = offset - new_offset;
588 if (delta > fp->_IO_buf_end - fp->_IO_buf_base)
590 new_offset = offset;
591 delta = 0;
593 result = _IO_SYSSEEK (fp, new_offset, 0);
594 if (result < 0)
595 return EOF;
596 if (delta == 0)
597 count = 0;
598 else
600 count = _IO_SYSREAD (fp, fp->_IO_buf_base,
601 (must_be_exact
602 ? delta : fp->_IO_buf_end - fp->_IO_buf_base));
603 if (count < delta)
605 /* We weren't allowed to read, but try to seek the remainder. */
606 offset = count == EOF ? delta : delta-count;
607 dir = _IO_seek_cur;
608 goto dumb;
611 _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + delta,
612 fp->_IO_buf_base + count);
613 _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
614 fp->_old_offset = result + count;
615 _IO_mask_flags (fp, 0, _IO_EOF_SEEN);
616 return offset;
617 dumb:
619 _IO_unsave_markers (fp);
620 result = _IO_SYSSEEK (fp, offset, dir);
621 if (result != EOF)
623 _IO_mask_flags (fp, 0, _IO_EOF_SEEN);
624 fp->_old_offset = result;
625 _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
626 _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
628 return result;
630 resync:
631 /* We need to do it since it is possible that the file offset in
632 the kernel may be changed behind our back. It may happen when
633 we fopen a file and then do a fork. One process may access the
634 the file and the kernel file offset will be changed. */
635 if (fp->_old_offset >= 0)
636 _IO_SYSSEEK (fp, fp->_old_offset, 0);
638 return offset;
641 _IO_ssize_t
642 _IO_old_file_write (f, data, n)
643 _IO_FILE *f;
644 const void *data;
645 _IO_ssize_t n;
647 _IO_ssize_t to_do = n;
648 while (to_do > 0)
650 _IO_ssize_t count = write (f->_fileno, data, to_do);
651 if (count == EOF)
653 f->_flags |= _IO_ERR_SEEN;
654 break;
656 to_do -= count;
657 data = (void *) ((char *) data + count);
659 n -= to_do;
660 if (f->_old_offset >= 0)
661 f->_old_offset += n;
662 return n;
665 _IO_size_t
666 _IO_old_file_xsputn (f, data, n)
667 _IO_FILE *f;
668 const void *data;
669 _IO_size_t n;
671 register const char *s = (char *) data;
672 _IO_size_t to_do = n;
673 int must_flush = 0;
674 _IO_size_t count;
676 if (n <= 0)
677 return 0;
678 /* This is an optimized implementation.
679 If the amount to be written straddles a block boundary
680 (or the filebuf is unbuffered), use sys_write directly. */
682 /* First figure out how much space is available in the buffer. */
683 count = f->_IO_write_end - f->_IO_write_ptr; /* Space available. */
684 if ((f->_flags & _IO_LINE_BUF) && (f->_flags & _IO_CURRENTLY_PUTTING))
686 count = f->_IO_buf_end - f->_IO_write_ptr;
687 if (count >= n)
689 register const char *p;
690 for (p = s + n; p > s; )
692 if (*--p == '\n')
694 count = p - s + 1;
695 must_flush = 1;
696 break;
701 /* Then fill the buffer. */
702 if (count > 0)
704 if (count > to_do)
705 count = to_do;
706 if (count > 20)
708 #ifdef _LIBC
709 f->_IO_write_ptr = __mempcpy (f->_IO_write_ptr, s, count);
710 #else
711 memcpy (f->_IO_write_ptr, s, count);
712 f->_IO_write_ptr += count;
713 #endif
714 s += count;
716 else
718 register char *p = f->_IO_write_ptr;
719 register int i = (int) count;
720 while (--i >= 0)
721 *p++ = *s++;
722 f->_IO_write_ptr = p;
724 to_do -= count;
726 if (to_do + must_flush > 0)
728 _IO_size_t block_size, do_write;
729 /* Next flush the (full) buffer. */
730 if (__overflow (f, EOF) == EOF)
731 return n - to_do;
733 /* Try to maintain alignment: write a whole number of blocks.
734 dont_write is what gets left over. */
735 block_size = f->_IO_buf_end - f->_IO_buf_base;
736 do_write = to_do - (block_size >= 128 ? to_do % block_size : 0);
738 if (do_write)
740 count = old_do_write (f, s, do_write);
741 to_do -= count;
742 if (count < do_write)
743 return n - to_do;
746 /* Now write out the remainder. Normally, this will fit in the
747 buffer, but it's somewhat messier for line-buffered files,
748 so we let _IO_default_xsputn handle the general case. */
749 if (to_do)
750 to_do -= _IO_default_xsputn (f, s+do_write, to_do);
752 return n - to_do;
756 struct _IO_jump_t _IO_old_file_jumps =
758 JUMP_INIT_DUMMY,
759 JUMP_INIT(finish, _IO_old_file_finish),
760 JUMP_INIT(overflow, _IO_old_file_overflow),
761 JUMP_INIT(underflow, _IO_old_file_underflow),
762 JUMP_INIT(uflow, _IO_default_uflow),
763 JUMP_INIT(pbackfail, _IO_default_pbackfail),
764 JUMP_INIT(xsputn, _IO_old_file_xsputn),
765 JUMP_INIT(xsgetn, _IO_default_xsgetn),
766 JUMP_INIT(seekoff, _IO_old_file_seekoff),
767 JUMP_INIT(seekpos, _IO_default_seekpos),
768 JUMP_INIT(setbuf, _IO_old_file_setbuf),
769 JUMP_INIT(sync, _IO_old_file_sync),
770 JUMP_INIT(doallocate, _IO_file_doallocate),
771 JUMP_INIT(read, _IO_file_read),
772 JUMP_INIT(write, _IO_old_file_write),
773 JUMP_INIT(seek, _IO_file_seek),
774 JUMP_INIT(close, _IO_file_close),
775 JUMP_INIT(stat, _IO_file_stat)
778 compat_symbol (libc, _IO_old_do_write, _IO_do_write, GLIBC_2_0);
779 compat_symbol (libc, _IO_old_file_attach, _IO_file_attach, GLIBC_2_0);
780 compat_symbol (libc, _IO_old_file_close_it, _IO_file_close_it, GLIBC_2_0);
781 compat_symbol (libc, _IO_old_file_finish, _IO_file_finish, GLIBC_2_0);
782 compat_symbol (libc, _IO_old_file_fopen, _IO_file_fopen, GLIBC_2_0);
783 compat_symbol (libc, _IO_old_file_init, _IO_file_init, GLIBC_2_0);
784 compat_symbol (libc, _IO_old_file_setbuf, _IO_file_setbuf, GLIBC_2_0);
785 compat_symbol (libc, _IO_old_file_sync, _IO_file_sync, GLIBC_2_0);
786 compat_symbol (libc, _IO_old_file_overflow, _IO_file_overflow, GLIBC_2_0);
787 compat_symbol (libc, _IO_old_file_seekoff, _IO_file_seekoff, GLIBC_2_0);
788 compat_symbol (libc, _IO_old_file_underflow, _IO_file_underflow, GLIBC_2_0);
789 compat_symbol (libc, _IO_old_file_write, _IO_file_write, GLIBC_2_0);
790 compat_symbol (libc, _IO_old_file_xsputn, _IO_file_xsputn, GLIBC_2_0);
792 #endif