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 * 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. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)fvwrite.c 8.1 (Berkeley) 6/4/93 37 * $FreeBSD: src/lib/libc/stdio/fvwrite.c,v 1.10 1999/08/28 00:01:06 peter Exp $ 38 * $DragonFly: src/lib/libc/stdio/fvwrite.c,v 1.5 2004/06/08 04:04:11 hmp Exp $ 39 */ 40 41 #include <errno.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include "local.h" 46 #include "fvwrite.h" 47 48 /* 49 * Write some memory regions. Return zero on success, EOF on error. 50 * 51 * This routine is large and unsightly, but most of the ugliness due 52 * to the three different kinds of output buffering is handled here. 53 */ 54 int 55 __sfvwrite(FILE *fp, struct __suio *uio) 56 { 57 size_t len; 58 char *p; 59 struct __siov *iov; 60 int w, s; 61 char *nl; 62 int nlknown, nldist; 63 64 if ((len = uio->uio_resid) == 0) 65 return (0); 66 /* make sure we can write */ 67 if (cantwrite(fp)) { 68 errno = EBADF; 69 return (EOF); 70 } 71 72 #define MIN(a, b) ((a) < (b) ? (a) : (b)) 73 #define COPY(n) (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n)) 74 75 iov = uio->uio_iov; 76 p = iov->iov_base; 77 len = iov->iov_len; 78 iov++; 79 #define GETIOV(extra_work) \ 80 while (len == 0) { \ 81 extra_work; \ 82 p = iov->iov_base; \ 83 len = iov->iov_len; \ 84 iov++; \ 85 } 86 if (fp->_flags & __SNBF) { 87 /* 88 * Unbuffered: write up to BUFSIZ bytes at a time. 89 */ 90 do { 91 GETIOV(;); 92 w = (*fp->_write)(fp->_cookie, p, MIN(len, BUFSIZ)); 93 if (w <= 0) 94 goto err; 95 p += w; 96 len -= w; 97 } while ((uio->uio_resid -= w) != 0); 98 } else if ((fp->_flags & __SLBF) == 0) { 99 /* 100 * Fully buffered: fill partially full buffer, if any, 101 * and then flush. If there is no partial buffer, write 102 * one _bf._size byte chunk directly (without copying). 103 * 104 * String output is a special case: write as many bytes 105 * as fit, but pretend we wrote everything. This makes 106 * snprintf() return the number of bytes needed, rather 107 * than the number used, and avoids its write function 108 * (so that the write function can be invalid). 109 */ 110 do { 111 GETIOV(;); 112 if ((fp->_flags & (__SALC | __SSTR)) == 113 (__SALC | __SSTR) && fp->_w < len) { 114 size_t blen = fp->_p - fp->_bf._base; 115 116 /* 117 * Alloc an extra 128 bytes (+ 1 for NULL) 118 * so we don't call realloc(3) so often. 119 */ 120 fp->_w = len + 128; 121 fp->_bf._size = blen + len + 128; 122 fp->_bf._base = 123 reallocf(fp->_bf._base, fp->_bf._size + 1); 124 if (fp->_bf._base == NULL) 125 goto err; 126 fp->_p = fp->_bf._base + blen; 127 } 128 w = fp->_w; 129 if (fp->_flags & __SSTR) { 130 if (len < w) 131 w = len; 132 if (w > 0) { 133 COPY(w); /* copy MIN(fp->_w,len), */ 134 fp->_w -= w; 135 fp->_p += w; 136 } 137 w = len; /* but pretend copied all */ 138 } else if (fp->_p > fp->_bf._base && len > w) { 139 /* fill and flush */ 140 COPY(w); 141 /* fp->_w -= w; */ /* unneeded */ 142 fp->_p += w; 143 if (fflush(fp)) 144 goto err; 145 } else if (len >= (w = fp->_bf._size)) { 146 /* write directly */ 147 w = (*fp->_write)(fp->_cookie, p, w); 148 if (w <= 0) 149 goto err; 150 } else { 151 /* fill and done */ 152 w = len; 153 COPY(w); 154 fp->_w -= w; 155 fp->_p += w; 156 } 157 p += w; 158 len -= w; 159 } while ((uio->uio_resid -= w) != 0); 160 } else { 161 /* 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). 167 */ 168 nlknown = 0; 169 nldist = 0; /* XXX just to keep gcc happy */ 170 do { 171 GETIOV(nlknown = 0); 172 if (!nlknown) { 173 nl = memchr((void *)p, '\n', len); 174 nldist = nl ? nl + 1 - p : len + 1; 175 nlknown = 1; 176 } 177 s = MIN(len, nldist); 178 w = fp->_w + fp->_bf._size; 179 if (fp->_p > fp->_bf._base && s > w) { 180 COPY(w); 181 /* fp->_w -= w; */ 182 fp->_p += w; 183 if (fflush(fp)) 184 goto err; 185 } else if (s >= (w = fp->_bf._size)) { 186 w = (*fp->_write)(fp->_cookie, p, w); 187 if (w <= 0) 188 goto err; 189 } else { 190 w = s; 191 COPY(w); 192 fp->_w -= w; 193 fp->_p += w; 194 } 195 if ((nldist -= w) == 0) { 196 /* copied the newline: flush and forget */ 197 if (fflush(fp)) 198 goto err; 199 nlknown = 0; 200 } 201 p += w; 202 len -= w; 203 } while ((uio->uio_resid -= w) != 0); 204 } 205 return (0); 206 207 err: 208 fp->_flags |= __SERR; 209 return (EOF); 210 } 211