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 <stdio.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include "local.h" 45 #include "fvwrite.h" 46 47 /* 48 * Write some memory regions. Return zero on success, EOF on error. 49 * 50 * This routine is large and unsightly, but most of the ugliness due 51 * to the three different kinds of output buffering is handled here. 52 */ 53 int 54 __sfvwrite(FILE *fp, struct __suio *uio) 55 { 56 size_t len; 57 unsigned char *old_p; 58 char *p; 59 struct __siov *iov; 60 int w, s; 61 char *nl; 62 int nlknown, nldist; 63 64 if (uio->uio_resid == 0) 65 return (0); 66 /* make sure we can write */ 67 if (prepwrite(fp) != 0) 68 return (EOF); 69 70 #define MIN(a, b) ((a) < (b) ? (a) : (b)) 71 #define COPY(n) (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n)) 72 73 iov = uio->uio_iov; 74 p = iov->iov_base; 75 len = iov->iov_len; 76 iov++; 77 #define GETIOV(extra_work) \ 78 while (len == 0) { \ 79 extra_work; \ 80 p = iov->iov_base; \ 81 len = iov->iov_len; \ 82 iov++; \ 83 } 84 if (fp->_flags & __SNBF) { 85 /* 86 * Unbuffered: write up to BUFSIZ bytes at a time. 87 */ 88 do { 89 GETIOV(;); 90 w = _swrite(fp, p, MIN(len, BUFSIZ)); 91 if (w <= 0) 92 goto err; 93 p += w; 94 len -= w; 95 } while ((uio->uio_resid -= w) != 0); 96 } else if ((fp->_flags & __SLBF) == 0) { 97 /* 98 * Fully buffered: fill partially full buffer, if any, 99 * and then flush. If there is no partial buffer, write 100 * one _bf._size byte chunk directly (without copying). 101 * 102 * String output is a special case: write as many bytes 103 * as fit, but pretend we wrote everything. This makes 104 * snprintf() return the number of bytes needed, rather 105 * than the number used, and avoids its write function 106 * (so that the write function can be invalid). 107 */ 108 do { 109 GETIOV(;); 110 if ((fp->_flags & (__SALC | __SSTR)) == 111 (__SALC | __SSTR) && fp->_w < len) { 112 size_t blen = fp->_p - fp->_bf._base; 113 114 /* 115 * Alloc an extra 128 bytes (+ 1 for NULL) 116 * so we don't call realloc(3) so often. 117 */ 118 fp->_w = len + 128; 119 fp->_bf._size = blen + len + 128; 120 fp->_bf._base = 121 reallocf(fp->_bf._base, fp->_bf._size + 1); 122 if (fp->_bf._base == NULL) 123 goto err; 124 fp->_p = fp->_bf._base + blen; 125 } 126 w = fp->_w; 127 if (fp->_flags & __SSTR) { 128 if (len < w) 129 w = len; 130 if (w > 0) { 131 COPY(w); /* copy MIN(fp->_w,len), */ 132 fp->_w -= w; 133 fp->_p += w; 134 } 135 w = len; /* but pretend copied all */ 136 } else if (fp->_p > fp->_bf._base && len > w) { 137 /* fill and flush */ 138 COPY(w); 139 /* fp->_w -= w; */ /* unneeded */ 140 fp->_p += w; 141 old_p = fp->_p; 142 if (__fflush(fp) == EOF) { 143 if (old_p == fp->_p) 144 fp->_p -= w; 145 goto err; 146 } 147 } else if (len >= (w = fp->_bf._size)) { 148 /* write directly */ 149 w = _swrite(fp, p, w); 150 if (w <= 0) 151 goto err; 152 } else { 153 /* fill and done */ 154 w = len; 155 COPY(w); 156 fp->_w -= w; 157 fp->_p += w; 158 } 159 p += w; 160 len -= w; 161 } while ((uio->uio_resid -= w) != 0); 162 } else { 163 /* 164 * Line buffered: like fully buffered, but we 165 * must check for newlines. Compute the distance 166 * to the first newline (including the newline), 167 * or `infinity' if there is none, then pretend 168 * that the amount to write is MIN(len,nldist). 169 */ 170 nlknown = 0; 171 nldist = 0; /* XXX just to keep gcc happy */ 172 do { 173 GETIOV(nlknown = 0); 174 if (!nlknown) { 175 nl = memchr((void *)p, '\n', len); 176 nldist = nl ? nl + 1 - p : len + 1; 177 nlknown = 1; 178 } 179 s = MIN(len, nldist); 180 w = fp->_w + fp->_bf._size; 181 if (fp->_p > fp->_bf._base && s > w) { 182 COPY(w); 183 /* fp->_w -= w; */ 184 fp->_p += w; 185 old_p = fp->_p; 186 if (__fflush(fp) == EOF) { 187 if (old_p == fp->_p) 188 fp->_p -= w; 189 goto err; 190 } 191 } else if (s >= (w = fp->_bf._size)) { 192 w = _swrite(fp, p, w); 193 if (w <= 0) 194 goto err; 195 } else { 196 w = s; 197 COPY(w); 198 fp->_w -= w; 199 fp->_p += w; 200 } 201 if ((nldist -= w) == 0) { 202 /* copied the newline: flush and forget */ 203 if (__fflush(fp)) 204 goto err; 205 nlknown = 0; 206 } 207 p += w; 208 len -= w; 209 } while ((uio->uio_resid -= w) != 0); 210 } 211 return (0); 212 213 err: 214 fp->_flags |= __SERR; 215 return (EOF); 216 } 217