2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1990, 1993
5 * The Regents of the University of California. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
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11 * modification, are permitted provided that the following conditions
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14 * notice, this list of conditions and the following disclaimer.
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17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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35 #if defined(LIBC_SCCS) && !defined(lint)
36 static char sccsid[] = "@(#)fvwrite.c 8.1 (Berkeley) 6/4/93";
37 #endif /* LIBC_SCCS and not lint */
46 * Write some memory regions. Return zero on success, EOF on error.
48 * This routine is large and unsightly, but most of the ugliness due
49 * to the three different kinds of output buffering is handled here.
52 __sfvwrite(FILE *fp, struct __suio *uio)
62 if (uio->uio_resid == 0)
64 /* make sure we can write */
65 if (prepwrite(fp) != 0)
68 #define MIN(a, b) ((a) < (b) ? (a) : (b))
69 #define COPY(n) (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n))
75 #define GETIOV(extra_work) \
82 if (fp->_flags & __SNBF) {
84 * Unbuffered: write up to BUFSIZ bytes at a time.
88 w = _swrite(fp, p, MIN(len, BUFSIZ));
93 } while ((uio->uio_resid -= w) != 0);
94 } else if ((fp->_flags & __SLBF) == 0) {
96 * Fully buffered: fill partially full buffer, if any,
97 * and then flush. If there is no partial buffer, write
98 * one _bf._size byte chunk directly (without copying).
100 * String output is a special case: write as many bytes
101 * as fit, but pretend we wrote everything. This makes
102 * snprintf() return the number of bytes needed, rather
103 * than the number used, and avoids its write function
104 * (so that the write function can be invalid).
108 if ((fp->_flags & (__SALC | __SSTR)) ==
109 (__SALC | __SSTR) && fp->_w < len) {
110 size_t blen = fp->_p - fp->_bf._base;
113 * Alloc an extra 128 bytes (+ 1 for NULL)
114 * so we don't call realloc(3) so often.
117 fp->_bf._size = blen + len + 128;
119 reallocf(fp->_bf._base, fp->_bf._size + 1);
120 if (fp->_bf._base == NULL)
122 fp->_p = fp->_bf._base + blen;
125 if (fp->_flags & __SSTR) {
129 COPY(w); /* copy MIN(fp->_w,len), */
133 w = len; /* but pretend copied all */
134 } else if (fp->_p > fp->_bf._base && len > w) {
137 /* fp->_w -= w; */ /* unneeded */
140 if (__fflush(fp) == EOF) {
145 } else if (len >= (w = fp->_bf._size)) {
147 w = _swrite(fp, p, w);
159 } while ((uio->uio_resid -= w) != 0);
162 * Line buffered: like fully buffered, but we
163 * must check for newlines. Compute the distance
164 * to the first newline (including the newline),
165 * or `infinity' if there is none, then pretend
166 * that the amount to write is MIN(len,nldist).
169 nldist = 0; /* XXX just to keep gcc happy */
173 nl = memchr((void *)p, '\n', len);
174 nldist = nl ? nl + 1 - p : len + 1;
177 s = MIN(len, nldist);
178 w = fp->_w + fp->_bf._size;
179 if (fp->_p > fp->_bf._base && s > w) {
184 if (__fflush(fp) == EOF) {
189 } else if (s >= (w = fp->_bf._size)) {
190 w = _swrite(fp, p, w);
199 if ((nldist -= w) == 0) {
200 /* copied the newline: flush and forget */
207 } while ((uio->uio_resid -= w) != 0);
212 fp->_flags |= __SERR;