1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Chris Torek. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 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 * 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 18 * without specific prior written permission. 19 * 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 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)fvwrite.c 8.1 (Berkeley) 6/4/93 33 * $FreeBSD: src/lib/libc/stdio/fvwrite.c,v 1.18 2007/01/09 00:28:06 imp Exp $ 34 * $DragonFly: src/lib/libc/stdio/fvwrite.c,v 1.7 2005/07/23 20:23:06 joerg Exp $ 35 */ 36 37 #include <stdio.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include "local.h" 41 #include "priv_stdio.h" 42 43 /* 44 * Write some memory regions. Return zero on success, EOF on error. 45 * 46 * This routine is large and unsightly, but most of the ugliness due 47 * to the three different kinds of output buffering is handled here. 48 */ 49 int 50 __sfvwrite(FILE *fp, struct __suio *uio) 51 { 52 size_t len; 53 char *p; 54 struct __siov *iov; 55 int w, s; 56 char *nl; 57 int nlknown, nldist; 58 59 if ((len = uio->uio_resid) == 0) 60 return (0); 61 /* make sure we can write */ 62 if (prepwrite(fp) != 0) 63 return (EOF); 64 65 #define MIN(a, b) ((a) < (b) ? (a) : (b)) 66 #define COPY(n) memcpy((void *)fp->pub._p, (void *)p, (size_t)(n)) 67 68 iov = uio->uio_iov; 69 p = iov->iov_base; 70 len = iov->iov_len; 71 iov++; 72 #define GETIOV(extra_work) \ 73 while (len == 0) { \ 74 extra_work; \ 75 p = iov->iov_base; \ 76 len = iov->iov_len; \ 77 iov++; \ 78 } 79 if (fp->pub._flags & __SNBF) { 80 /* 81 * Unbuffered: write up to BUFSIZ bytes at a time. 82 */ 83 do { 84 GETIOV(;); 85 w = _swrite(fp, p, MIN(len, BUFSIZ)); 86 if (w <= 0) 87 goto err; 88 p += w; 89 len -= w; 90 } while ((uio->uio_resid -= w) != 0); 91 } else if ((fp->pub._flags & __SLBF) == 0) { 92 /* 93 * Fully buffered: fill partially full buffer, if any, 94 * and then flush. If there is no partial buffer, write 95 * one _bf._size byte chunk directly (without copying). 96 * 97 * String output is a special case: write as many bytes 98 * as fit, but pretend we wrote everything. This makes 99 * snprintf() return the number of bytes needed, rather 100 * than the number used, and avoids its write function 101 * (so that the write function can be invalid). 102 */ 103 do { 104 GETIOV(;); 105 if ((fp->pub._flags & (__SALC | __SSTR)) == 106 (__SALC | __SSTR) && fp->pub._w < len) { 107 size_t blen = fp->pub._p - fp->_bf._base; 108 109 /* 110 * Alloc an extra 128 bytes (+ 1 for NULL) 111 * so we don't call realloc(3) so often. 112 */ 113 fp->pub._w = len + 128; 114 fp->_bf._size = blen + len + 128; 115 fp->_bf._base = 116 reallocf(fp->_bf._base, fp->_bf._size + 1); 117 if (fp->_bf._base == NULL) 118 goto err; 119 fp->pub._p = fp->_bf._base + blen; 120 } 121 w = fp->pub._w; 122 if (fp->pub._flags & __SSTR) { 123 if (len < w) 124 w = len; 125 if (w > 0) { 126 COPY(w); /* copy MIN(fp->pub._w, len), */ 127 fp->pub._w -= w; 128 fp->pub._p += w; 129 } 130 w = len; /* but pretend copied all */ 131 } else if (fp->pub._p > fp->_bf._base && len > w) { 132 /* fill and flush */ 133 COPY(w); 134 /* fp->pub._w -= w; */ /* unneeded */ 135 fp->pub._p += w; 136 if (__fflush(fp)) 137 goto err; 138 } else if (len >= (w = fp->_bf._size)) { 139 /* write directly */ 140 w = _swrite(fp, p, w); 141 if (w <= 0) 142 goto err; 143 } else { 144 /* fill and done */ 145 w = len; 146 COPY(w); 147 fp->pub._w -= w; 148 fp->pub._p += w; 149 } 150 p += w; 151 len -= w; 152 } while ((uio->uio_resid -= w) != 0); 153 } else { 154 /* 155 * Line buffered: like fully buffered, but we 156 * must check for newlines. Compute the distance 157 * to the first newline (including the newline), 158 * or `infinity' if there is none, then pretend 159 * that the amount to write is MIN(len,nldist). 160 */ 161 nlknown = 0; 162 nldist = 0; /* XXX just to keep gcc happy */ 163 do { 164 GETIOV(nlknown = 0); 165 if (!nlknown) { 166 nl = memchr((void *)p, '\n', len); 167 nldist = nl ? nl + 1 - p : len + 1; 168 nlknown = 1; 169 } 170 s = MIN(len, nldist); 171 w = fp->pub._w + fp->_bf._size; 172 if (fp->pub._p > fp->_bf._base && s > w) { 173 COPY(w); 174 /* fp->pub._w -= w; */ 175 fp->pub._p += w; 176 if (__fflush(fp)) 177 goto err; 178 } else if (s >= (w = fp->_bf._size)) { 179 w = _swrite(fp, p, w); 180 if (w <= 0) 181 goto err; 182 } else { 183 w = s; 184 COPY(w); 185 fp->pub._w -= w; 186 fp->pub._p += w; 187 } 188 if ((nldist -= w) == 0) { 189 /* copied the newline: flush and forget */ 190 if (__fflush(fp)) 191 goto err; 192 nlknown = 0; 193 } 194 p += w; 195 len -= w; 196 } while ((uio->uio_resid -= w) != 0); 197 } 198 return (0); 199 200 err: 201 fp->pub._flags |= __SERR; 202 return (EOF); 203 } 204