2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
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9 * modification, are permitted provided that the following conditions
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12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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37 #if defined(LIBC_SCCS) && !defined(lint)
39 static char sccsid[] = "@(#)fvwrite.c 8.1 (Berkeley) 6/4/93";
41 static const char rcsid[] =
43 #endif /* LIBC_SCCS and not lint */
52 * Write some memory regions. Return zero on success, EOF on error.
54 * This routine is large and unsightly, but most of the ugliness due
55 * to the three different kinds of output buffering is handled here.
60 register struct __suio *uio;
64 register struct __siov *iov;
69 if ((len = uio->uio_resid) == 0)
71 /* make sure we can write */
75 #define MIN(a, b) ((a) < (b) ? (a) : (b))
76 #define COPY(n) (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n))
82 #define GETIOV(extra_work) \
89 if (fp->_flags & __SNBF) {
91 * Unbuffered: write up to BUFSIZ bytes at a time.
95 w = (*fp->_write)(fp->_cookie, p, MIN(len, BUFSIZ));
100 } while ((uio->uio_resid -= w) != 0);
101 } else if ((fp->_flags & __SLBF) == 0) {
103 * Fully buffered: fill partially full buffer, if any,
104 * and then flush. If there is no partial buffer, write
105 * one _bf._size byte chunk directly (without copying).
107 * String output is a special case: write as many bytes
108 * as fit, but pretend we wrote everything. This makes
109 * snprintf() return the number of bytes needed, rather
110 * than the number used, and avoids its write function
111 * (so that the write function can be invalid).
115 if ((fp->_flags & (__SALC | __SSTR)) ==
116 (__SALC | __SSTR) && fp->_w < len) {
117 size_t blen = fp->_p - fp->_bf._base;
120 * Alloc an extra 128 bytes (+ 1 for NULL)
121 * so we don't call realloc(3) so often.
124 fp->_bf._size = blen + len + 128;
126 reallocf(fp->_bf._base, fp->_bf._size + 1);
127 if (fp->_bf._base == NULL)
129 fp->_p = fp->_bf._base + blen;
132 if (fp->_flags & __SSTR) {
136 COPY(w); /* copy MIN(fp->_w,len), */
140 w = len; /* but pretend copied all */
141 } else if (fp->_p > fp->_bf._base && len > w) {
144 /* fp->_w -= w; */ /* unneeded */
148 } else if (len >= (w = fp->_bf._size)) {
150 w = (*fp->_write)(fp->_cookie, p, w);
162 } while ((uio->uio_resid -= w) != 0);
165 * Line buffered: like fully buffered, but we
166 * must check for newlines. Compute the distance
167 * to the first newline (including the newline),
168 * or `infinity' if there is none, then pretend
169 * that the amount to write is MIN(len,nldist).
172 nldist = 0; /* XXX just to keep gcc happy */
176 nl = memchr((void *)p, '\n', len);
177 nldist = nl ? nl + 1 - p : len + 1;
180 s = MIN(len, nldist);
181 w = fp->_w + fp->_bf._size;
182 if (fp->_p > fp->_bf._base && s > w) {
188 } else if (s >= (w = fp->_bf._size)) {
189 w = (*fp->_write)(fp->_cookie, p, w);
198 if ((nldist -= w) == 0) {
199 /* copied the newline: flush and forget */
206 } while ((uio->uio_resid -= w) != 0);
211 fp->_flags |= __SERR;