1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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. 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. 21 * 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 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 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 */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 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 unsigned char *old_p; 59 char *p; 60 struct __siov *iov; 61 int w, s; 62 char *nl; 63 int nlknown, nldist; 64 65 if (uio->uio_resid == 0) 66 return (0); 67 /* make sure we can write */ 68 if (prepwrite(fp) != 0) 69 return (EOF); 70 71 #define MIN(a, b) ((a) < (b) ? (a) : (b)) 72 #define COPY(n) (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n)) 73 74 iov = uio->uio_iov; 75 p = iov->iov_base; 76 len = iov->iov_len; 77 iov++; 78 #define GETIOV(extra_work) \ 79 while (len == 0) { \ 80 extra_work; \ 81 p = iov->iov_base; \ 82 len = iov->iov_len; \ 83 iov++; \ 84 } 85 if (fp->_flags & __SNBF) { 86 /* 87 * Unbuffered: write up to BUFSIZ bytes at a time. 88 */ 89 do { 90 GETIOV(;); 91 w = _swrite(fp, p, MIN(len, BUFSIZ)); 92 if (w <= 0) 93 goto err; 94 p += w; 95 len -= w; 96 } while ((uio->uio_resid -= w) != 0); 97 } else if ((fp->_flags & __SLBF) == 0) { 98 /* 99 * Fully buffered: fill partially full buffer, if any, 100 * and then flush. If there is no partial buffer, write 101 * one _bf._size byte chunk directly (without copying). 102 * 103 * String output is a special case: write as many bytes 104 * as fit, but pretend we wrote everything. This makes 105 * snprintf() return the number of bytes needed, rather 106 * than the number used, and avoids its write function 107 * (so that the write function can be invalid). 108 */ 109 do { 110 GETIOV(;); 111 if ((fp->_flags & (__SALC | __SSTR)) == 112 (__SALC | __SSTR) && fp->_w < len) { 113 size_t blen = fp->_p - fp->_bf._base; 114 115 /* 116 * Alloc an extra 128 bytes (+ 1 for NULL) 117 * so we don't call realloc(3) so often. 118 */ 119 fp->_w = len + 128; 120 fp->_bf._size = blen + len + 128; 121 fp->_bf._base = 122 reallocf(fp->_bf._base, fp->_bf._size + 1); 123 if (fp->_bf._base == NULL) 124 goto err; 125 fp->_p = fp->_bf._base + blen; 126 } 127 w = fp->_w; 128 if (fp->_flags & __SSTR) { 129 if (len < w) 130 w = len; 131 if (w > 0) { 132 COPY(w); /* copy MIN(fp->_w,len), */ 133 fp->_w -= w; 134 fp->_p += w; 135 } 136 w = len; /* but pretend copied all */ 137 } else if (fp->_p > fp->_bf._base && len > w) { 138 /* fill and flush */ 139 COPY(w); 140 /* fp->_w -= w; */ /* unneeded */ 141 fp->_p += w; 142 old_p = fp->_p; 143 if (__fflush(fp) == EOF) { 144 if (old_p == fp->_p && errno == EINTR) 145 fp->_p -= w; 146 goto err; 147 } 148 } else if (len >= (w = fp->_bf._size)) { 149 /* write directly */ 150 w = _swrite(fp, p, w); 151 if (w <= 0) 152 goto err; 153 } else { 154 /* fill and done */ 155 w = len; 156 COPY(w); 157 fp->_w -= w; 158 fp->_p += w; 159 } 160 p += w; 161 len -= w; 162 } while ((uio->uio_resid -= w) != 0); 163 } else { 164 /* 165 * Line buffered: like fully buffered, but we 166 * must check for newlines. Compute the distance 167 * to the first newline (including the newline), 168 * or `infinity' if there is none, then pretend 169 * that the amount to write is MIN(len,nldist). 170 */ 171 nlknown = 0; 172 nldist = 0; /* XXX just to keep gcc happy */ 173 do { 174 GETIOV(nlknown = 0); 175 if (!nlknown) { 176 nl = memchr((void *)p, '\n', len); 177 nldist = nl ? nl + 1 - p : len + 1; 178 nlknown = 1; 179 } 180 s = MIN(len, nldist); 181 w = fp->_w + fp->_bf._size; 182 if (fp->_p > fp->_bf._base && s > w) { 183 COPY(w); 184 /* fp->_w -= w; */ 185 fp->_p += w; 186 old_p = fp->_p; 187 if (__fflush(fp) == EOF) { 188 if (old_p == fp->_p && errno == EINTR) 189 fp->_p -= w; 190 goto err; 191 } 192 } else if (s >= (w = fp->_bf._size)) { 193 w = _swrite(fp, p, w); 194 if (w <= 0) 195 goto err; 196 } else { 197 w = s; 198 COPY(w); 199 fp->_w -= w; 200 fp->_p += w; 201 } 202 if ((nldist -= w) == 0) { 203 /* copied the newline: flush and forget */ 204 if (__fflush(fp)) 205 goto err; 206 nlknown = 0; 207 } 208 p += w; 209 len -= w; 210 } while ((uio->uio_resid -= w) != 0); 211 } 212 return (0); 213 214 err: 215 fp->_flags |= __SERR; 216 return (EOF); 217 } 218