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