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 <errno.h> 39 #include <stdio.h> 40 #include <stdlib.h> 41 #include <string.h> 42 #include "local.h" 43 #include "fvwrite.h" 44 45 /* 46 * Write some memory regions. Return zero on success, EOF on error. 47 * 48 * This routine is large and unsightly, but most of the ugliness due 49 * to the three different kinds of output buffering is handled here. 50 */ 51 int 52 __sfvwrite(FILE *fp, struct __suio *uio) 53 { 54 size_t len; 55 unsigned char *old_p; 56 char *p; 57 struct __siov *iov; 58 int w, s; 59 char *nl; 60 int nlknown, nldist; 61 62 if (uio->uio_resid == 0) 63 return (0); 64 /* make sure we can write */ 65 if (prepwrite(fp) != 0) 66 return (EOF); 67 68 #define MIN(a, b) ((a) < (b) ? (a) : (b)) 69 #define COPY(n) (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n)) 70 71 iov = uio->uio_iov; 72 p = iov->iov_base; 73 len = iov->iov_len; 74 iov++; 75 #define GETIOV(extra_work) \ 76 while (len == 0) { \ 77 extra_work; \ 78 p = iov->iov_base; \ 79 len = iov->iov_len; \ 80 iov++; \ 81 } 82 if (fp->_flags & __SNBF) { 83 /* 84 * Unbuffered: write up to BUFSIZ bytes at a time. 85 */ 86 do { 87 GETIOV(;); 88 w = _swrite(fp, p, MIN(len, BUFSIZ)); 89 if (w <= 0) 90 goto err; 91 p += w; 92 len -= w; 93 } while ((uio->uio_resid -= w) != 0); 94 } else if ((fp->_flags & __SLBF) == 0) { 95 /* 96 * Fully buffered: fill partially full buffer, if any, 97 * and then flush. If there is no partial buffer, write 98 * one _bf._size byte chunk directly (without copying). 99 * 100 * String output is a special case: write as many bytes 101 * as fit, but pretend we wrote everything. This makes 102 * snprintf() return the number of bytes needed, rather 103 * than the number used, and avoids its write function 104 * (so that the write function can be invalid). 105 */ 106 do { 107 GETIOV(;); 108 if ((fp->_flags & (__SALC | __SSTR)) == 109 (__SALC | __SSTR) && fp->_w < len) { 110 size_t blen = fp->_p - fp->_bf._base; 111 112 /* 113 * Alloc an extra 128 bytes (+ 1 for NULL) 114 * so we don't call realloc(3) so often. 115 */ 116 fp->_w = len + 128; 117 fp->_bf._size = blen + len + 128; 118 fp->_bf._base = 119 reallocf(fp->_bf._base, fp->_bf._size + 1); 120 if (fp->_bf._base == NULL) 121 goto err; 122 fp->_p = fp->_bf._base + blen; 123 } 124 w = fp->_w; 125 if (fp->_flags & __SSTR) { 126 if (len < w) 127 w = len; 128 if (w > 0) { 129 COPY(w); /* copy MIN(fp->_w,len), */ 130 fp->_w -= w; 131 fp->_p += w; 132 } 133 w = len; /* but pretend copied all */ 134 } else if (fp->_p > fp->_bf._base && len > w) { 135 /* fill and flush */ 136 COPY(w); 137 /* fp->_w -= w; */ /* unneeded */ 138 fp->_p += w; 139 old_p = fp->_p; 140 if (__fflush(fp) == EOF) { 141 if (old_p == fp->_p && errno == EINTR) 142 fp->_p -= w; 143 goto err; 144 } 145 } else if (len >= (w = fp->_bf._size)) { 146 /* write directly */ 147 w = _swrite(fp, 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 old_p = fp->_p; 184 if (__fflush(fp) == EOF) { 185 if (old_p == fp->_p && errno == EINTR) 186 fp->_p -= w; 187 goto err; 188 } 189 } else if (s >= (w = fp->_bf._size)) { 190 w = _swrite(fp, p, w); 191 if (w <= 0) 192 goto err; 193 } else { 194 w = s; 195 COPY(w); 196 fp->_w -= w; 197 fp->_p += w; 198 } 199 if ((nldist -= w) == 0) { 200 /* copied the newline: flush and forget */ 201 if (__fflush(fp)) 202 goto err; 203 nlknown = 0; 204 } 205 p += w; 206 len -= w; 207 } while ((uio->uio_resid -= w) != 0); 208 } 209 return (0); 210 211 err: 212 fp->_flags |= __SERR; 213 return (EOF); 214 } 215