2 Unix SMB/CIFS implementation.
4 Copyright (C) Andrew Tridgell 2001
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 stdio is very convenient, but on some systems the file descriptor
23 in FILE* is 8 bits, so it fails when more than 255 files are open.
25 XFILE replaces stdio. It is less efficient, but at least it works
26 when you have lots of files open
28 The main restriction on XFILE is that it doesn't support seeking,
29 and doesn't support O_RDWR. That keeps the code simple.
34 #define XBUFSIZE BUFSIZ
36 static XFILE _x_stdin = { 0, NULL, NULL, XBUFSIZE, 0, O_RDONLY, X_IOFBF, 0 };
37 static XFILE _x_stdout = { 1, NULL, NULL, XBUFSIZE, 0, O_WRONLY, X_IOLBF, 0 };
38 static XFILE _x_stderr = { 2, NULL, NULL, 0, 0, O_WRONLY, X_IONBF, 0 };
40 XFILE *x_stdin = &_x_stdin;
41 XFILE *x_stdout = &_x_stdout;
42 XFILE *x_stderr = &_x_stderr;
45 #define X_FLAG_ERROR 2
46 #define X_FLAG_EINVAL 3
48 /* simulate setvbuf() */
49 int x_setvbuf(XFILE *f, char *buf, int mode, size_t size)
52 if (f->bufused) return -1;
54 /* on files being read full buffering is the only option */
55 if ((f->open_flags & O_ACCMODE) == O_RDONLY) {
59 /* destroy any earlier buffer */
67 if (f->buftype == X_IONBF) return 0;
69 /* if buffering then we need some size */
70 if (size == 0) size = XBUFSIZE;
78 /* allocate the buffer */
79 static int x_allocate_buffer(XFILE *f)
82 if (f->bufsize == 0) return 0;
83 f->buf = malloc(f->bufsize);
84 if (!f->buf) return 0;
90 /* this looks more like open() than fopen(), but that is quite deliberate.
91 I want programmers to *think* about O_EXCL, O_CREAT etc not just
92 get them magically added
94 XFILE *x_fopen(const char *fname, int flags, mode_t mode)
98 ret = (XFILE *)malloc(sizeof(XFILE));
99 if (!ret) return NULL;
101 memset(ret, 0, sizeof(XFILE));
103 if ((flags & O_ACCMODE) == O_RDWR) {
104 /* we don't support RDWR in XFILE - use file
105 descriptors instead */
110 ret->open_flags = flags;
112 ret->fd = sys_open(fname, flags, mode);
118 x_setvbuf(ret, NULL, X_IOFBF, XBUFSIZE);
123 /* simulate fclose() */
124 int x_fclose(XFILE *f)
128 /* make sure we flush any buffered data */
134 /* make sure data can't leak into a later malloc */
135 memset(f->buf, 0, f->bufsize);
142 /* simulate fwrite() */
143 int x_fwrite(const void *p, size_t size, size_t nmemb, XFILE *f)
147 /* we might be writing unbuffered */
148 if (f->buftype == X_IONBF ||
149 (!f->buf && !x_allocate_buffer(f))) {
150 ret = write(f->fd, p, size*nmemb);
151 if (ret == -1) return -1;
156 while (total < size*nmemb) {
157 int n = f->bufsize - f->bufused;
158 n = MIN(n, (size*nmemb)-total);
161 /* it's full, flush it */
166 memcpy(f->buf + f->bufused, total+(const char *)p, n);
171 /* when line buffered we need to flush at the last linefeed. This can
172 flush a bit more than necessary, but that is harmless */
173 if (f->buftype == X_IOLBF && f->bufused) {
175 for (i=(size*nmemb)-1; i>=0; i--) {
176 if (*(i+(const char *)p) == '\n') {
186 /* thank goodness for asprintf() */
187 int x_vfprintf(XFILE *f, const char *format, va_list ap)
195 len = vasprintf(&p, format, ap2);
196 if (len <= 0) return len;
197 ret = x_fwrite(p, 1, len, f);
202 int x_fprintf(XFILE *f, const char *format, ...)
207 va_start(ap, format);
208 ret = x_vfprintf(f, format, ap);
213 /* at least fileno() is simple! */
214 int x_fileno(XFILE *f)
219 /* simulate fflush() */
220 int x_fflush(XFILE *f)
224 if (f->flags & X_FLAG_ERROR) return -1;
226 if ((f->open_flags & O_ACCMODE) != O_WRONLY) {
231 if (f->bufused == 0) return 0;
233 ret = write(f->fd, f->buf, f->bufused);
234 if (ret == -1) return -1;
237 if (f->bufused > 0) {
238 f->flags |= X_FLAG_ERROR;
239 memmove(f->buf, ret + (char *)f->buf, f->bufused);
246 /* simulate setbuffer() */
247 void x_setbuffer(XFILE *f, char *buf, size_t size)
249 x_setvbuf(f, buf, buf?X_IOFBF:X_IONBF, size);
252 /* simulate setbuf() */
253 void x_setbuf(XFILE *f, char *buf)
255 x_setvbuf(f, buf, buf?X_IOFBF:X_IONBF, XBUFSIZE);
258 /* simulate setlinebuf() */
259 void x_setlinebuf(XFILE *f)
261 x_setvbuf(f, NULL, X_IOLBF, 0);
265 /* simulate feof() */
268 if (f->flags & X_FLAG_EOF) return 1;
272 /* simulate ferror() */
273 int x_ferror(XFILE *f)
275 if (f->flags & X_FLAG_ERROR) return 1;
279 /* fill the read buffer */
280 static void x_fillbuf(XFILE *f)
284 if (f->bufused) return;
286 if (!f->buf && !x_allocate_buffer(f)) return;
288 n = read(f->fd, f->buf, f->bufsize);
294 /* simulate fgetc() */
295 int x_fgetc(XFILE *f)
299 if (f->flags & (X_FLAG_EOF | X_FLAG_ERROR)) return EOF;
301 if (f->bufused == 0) x_fillbuf(f);
303 if (f->bufused == 0) {
304 f->flags |= X_FLAG_EOF;
308 ret = *(unsigned char *)(f->next);
315 size_t x_fread(void *p, size_t size, size_t nmemb, XFILE *f)
318 while (total < size*nmemb) {
321 (total+(char *)p)[0] = (char)c;
327 /* simulate fgets() */
328 char *x_fgets(char *s, int size, XFILE *stream)
333 int c = x_fgetc(stream);
337 if (c == '\n') break;
339 if (l==size || x_ferror(stream)) {
346 /* trivial seek, works only for SEEK_SET and SEEK_END if SEEK_CUR is
347 * set then an error is returned */
348 off_t x_tseek(XFILE *f, off_t offset, int whence)
350 if (f->flags & X_FLAG_ERROR)
353 /* only SEEK_SET and SEEK_END are supported */
354 /* SEEK_CUR needs internal offset counter */
355 if (whence != SEEK_SET && whence != SEEK_END) {
356 f->flags |= X_FLAG_EINVAL;
361 /* empty the buffer */
362 switch (f->open_flags & O_ACCMODE) {
367 if (x_fflush(f) != 0)
375 f->flags &= ~X_FLAG_EOF;
376 return (off_t)sys_lseek(f->fd, offset, whence);