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