1 /* $NetBSD: fvwrite.c,v 1.11 1998/11/15 17:19:53 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 #if 0 42 static char sccsid[] = "@(#)fvwrite.c 8.1 (Berkeley) 6/4/93"; 43 #else 44 __RCSID("$NetBSD: fvwrite.c,v 1.11 1998/11/15 17:19:53 christos Exp $"); 45 #endif 46 #endif /* LIBC_SCCS and not lint */ 47 48 #include <errno.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include "local.h" 53 #include "fvwrite.h" 54 55 /* 56 * Write some memory regions. Return zero on success, EOF on error. 57 * 58 * This routine is large and unsightly, but most of the ugliness due 59 * to the three different kinds of output buffering is handled here. 60 */ 61 int 62 __sfvwrite(fp, uio) 63 FILE *fp; 64 struct __suio *uio; 65 { 66 size_t len; 67 char *p; 68 struct __siov *iov; 69 int w, s; 70 char *nl; 71 int nlknown, nldist; 72 73 if ((len = uio->uio_resid) == 0) 74 return (0); 75 /* make sure we can write */ 76 if (cantwrite(fp)) { 77 errno = EBADF; 78 return (EOF); 79 } 80 81 #define MIN(a, b) ((a) < (b) ? (a) : (b)) 82 #define COPY(n) (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n)) 83 84 iov = uio->uio_iov; 85 p = iov->iov_base; 86 len = iov->iov_len; 87 iov++; 88 #define GETIOV(extra_work) \ 89 while (len == 0) { \ 90 extra_work; \ 91 p = iov->iov_base; \ 92 len = iov->iov_len; \ 93 iov++; \ 94 } 95 if (fp->_flags & __SNBF) { 96 /* 97 * Unbuffered: write up to BUFSIZ bytes at a time. 98 */ 99 do { 100 GETIOV(;); 101 w = (*fp->_write)(fp->_cookie, p, 102 (int)MIN(len, BUFSIZ)); 103 if (w <= 0) 104 goto err; 105 p += w; 106 len -= w; 107 } while ((uio->uio_resid -= w) != 0); 108 } else if ((fp->_flags & __SLBF) == 0) { 109 /* 110 * Fully buffered: fill partially full buffer, if any, 111 * and then flush. If there is no partial buffer, write 112 * one _bf._size byte chunk directly (without copying). 113 * 114 * String output is a special case: write as many bytes 115 * as fit, but pretend we wrote everything. This makes 116 * snprintf() return the number of bytes needed, rather 117 * than the number used, and avoids its write function 118 * (so that the write function can be invalid). 119 */ 120 do { 121 GETIOV(;); 122 if ((fp->_flags & (__SALC | __SSTR)) == 123 (__SALC | __SSTR) && fp->_w < len) { 124 size_t blen = fp->_p - fp->_bf._base; 125 unsigned char *_base; 126 int _size; 127 128 /* Allocate space exponentially. */ 129 _size = fp->_bf._size; 130 do { 131 _size = (_size << 1) + 1; 132 } while (_size < blen + len); 133 _base = realloc(fp->_bf._base, 134 (size_t)(_size + 1)); 135 if (_base == NULL) 136 goto err; 137 fp->_w += _size - fp->_bf._size; 138 fp->_bf._base = _base; 139 fp->_bf._size = _size; 140 fp->_p = _base + blen; 141 } 142 w = fp->_w; 143 if (fp->_flags & __SSTR) { 144 if (len < w) 145 w = len; 146 COPY(w); /* copy MIN(fp->_w,len), */ 147 fp->_w -= w; 148 fp->_p += w; 149 w = len; /* but pretend copied all */ 150 } else if (fp->_p > fp->_bf._base && len > w) { 151 /* fill and flush */ 152 COPY(w); 153 /* fp->_w -= w; */ /* unneeded */ 154 fp->_p += w; 155 if (fflush(fp)) 156 goto err; 157 } else if (len >= (w = fp->_bf._size)) { 158 /* write directly */ 159 w = (*fp->_write)(fp->_cookie, p, w); 160 if (w <= 0) 161 goto err; 162 } else { 163 /* fill and done */ 164 w = len; 165 COPY(w); 166 fp->_w -= w; 167 fp->_p += w; 168 } 169 p += w; 170 len -= w; 171 } while ((uio->uio_resid -= w) != 0); 172 } else { 173 /* 174 * Line buffered: like fully buffered, but we 175 * must check for newlines. Compute the distance 176 * to the first newline (including the newline), 177 * or `infinity' if there is none, then pretend 178 * that the amount to write is MIN(len,nldist). 179 */ 180 nlknown = 0; 181 nldist = 0; /* XXX just to keep gcc happy */ 182 do { 183 GETIOV(nlknown = 0); 184 if (!nlknown) { 185 nl = memchr((void *)p, '\n', len); 186 nldist = nl ? nl + 1 - p : len + 1; 187 nlknown = 1; 188 } 189 s = MIN(len, nldist); 190 w = fp->_w + fp->_bf._size; 191 if (fp->_p > fp->_bf._base && s > w) { 192 COPY(w); 193 /* fp->_w -= w; */ 194 fp->_p += w; 195 if (fflush(fp)) 196 goto err; 197 } else if (s >= (w = fp->_bf._size)) { 198 w = (*fp->_write)(fp->_cookie, p, w); 199 if (w <= 0) 200 goto err; 201 } else { 202 w = s; 203 COPY(w); 204 fp->_w -= w; 205 fp->_p += w; 206 } 207 if ((nldist -= w) == 0) { 208 /* copied the newline: flush and forget */ 209 if (fflush(fp)) 210 goto err; 211 nlknown = 0; 212 } 213 p += w; 214 len -= w; 215 } while ((uio->uio_resid -= w) != 0); 216 } 217 return (0); 218 219 err: 220 fp->_flags |= __SERR; 221 return (EOF); 222 } 223