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
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16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
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20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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33 #if defined(LIBC_SCCS) && !defined(lint)
34 static char sccsid[] = "@(#)fvwrite.c 8.1 (Berkeley) 6/4/93";
35 #endif /* LIBC_SCCS and not lint */
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
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.
63 if (uio->uio_resid == 0)
65 /* make sure we can write */
66 if (prepwrite(fp) != 0)
69 #define MIN(a, b) ((a) < (b) ? (a) : (b))
70 #define COPY(n) (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n))
76 #define GETIOV(extra_work) \
83 if (fp->_flags & __SNBF) {
85 * Unbuffered: write up to BUFSIZ bytes at a time.
89 w = _swrite(fp, p, MIN(len, BUFSIZ));
94 } while ((uio->uio_resid -= w) != 0);
95 } else if ((fp->_flags & __SLBF) == 0) {
97 * Fully buffered: fill partially full buffer, if any,
98 * and then flush. If there is no partial buffer, write
99 * one _bf._size byte chunk directly (without copying).
101 * String output is a special case: write as many bytes
102 * as fit, but pretend we wrote everything. This makes
103 * snprintf() return the number of bytes needed, rather
104 * than the number used, and avoids its write function
105 * (so that the write function can be invalid).
109 if ((fp->_flags & (__SALC | __SSTR)) ==
110 (__SALC | __SSTR) && fp->_w < len) {
111 size_t blen = fp->_p - fp->_bf._base;
114 * Alloc an extra 128 bytes (+ 1 for NULL)
115 * so we don't call realloc(3) so often.
118 fp->_bf._size = blen + len + 128;
120 reallocf(fp->_bf._base, fp->_bf._size + 1);
121 if (fp->_bf._base == NULL)
123 fp->_p = fp->_bf._base + blen;
126 if (fp->_flags & __SSTR) {
130 COPY(w); /* copy MIN(fp->_w,len), */
134 w = len; /* but pretend copied all */
135 } else if (fp->_p > fp->_bf._base && len > w) {
138 /* fp->_w -= w; */ /* unneeded */
142 } else if (len >= (w = fp->_bf._size)) {
144 w = _swrite(fp, p, w);
156 } while ((uio->uio_resid -= w) != 0);
159 * Line buffered: like fully buffered, but we
160 * must check for newlines. Compute the distance
161 * to the first newline (including the newline),
162 * or `infinity' if there is none, then pretend
163 * that the amount to write is MIN(len,nldist).
166 nldist = 0; /* XXX just to keep gcc happy */
170 nl = memchr((void *)p, '\n', len);
171 nldist = nl ? nl + 1 - p : len + 1;
174 s = MIN(len, nldist);
175 w = fp->_w + fp->_bf._size;
176 if (fp->_p > fp->_bf._base && s > w) {
182 } else if (s >= (w = fp->_bf._size)) {
183 w = _swrite(fp, p, w);
192 if ((nldist -= w) == 0) {
193 /* copied the newline: flush and forget */
200 } while ((uio->uio_resid -= w) != 0);
205 fp->_flags |= __SERR;