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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #if defined(LIBC_SCCS) && !defined(lint) 38 static char sccsid[] = "@(#)fvwrite.c 8.1 (Berkeley) 6/4/93"; 39 #endif /* LIBC_SCCS and not lint */ 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD$"); 42 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include "local.h" 47 #include "fvwrite.h" 48 49 /* 50 * Write some memory regions. Return zero on success, EOF on error. 51 * 52 * This routine is large and unsightly, but most of the ugliness due 53 * to the three different kinds of output buffering is handled here. 54 */ 55 int 56 __sfvwrite(fp, uio) 57 FILE *fp; 58 struct __suio *uio; 59 { 60 size_t len; 61 char *p; 62 struct __siov *iov; 63 int w, s; 64 char *nl; 65 int nlknown, nldist; 66 67 if ((len = uio->uio_resid) == 0) 68 return (0); 69 /* make sure we can write */ 70 if (prepwrite(fp) != 0) 71 return (EOF); 72 73 #define MIN(a, b) ((a) < (b) ? (a) : (b)) 74 #define COPY(n) (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n)) 75 76 iov = uio->uio_iov; 77 p = iov->iov_base; 78 len = iov->iov_len; 79 iov++; 80 #define GETIOV(extra_work) \ 81 while (len == 0) { \ 82 extra_work; \ 83 p = iov->iov_base; \ 84 len = iov->iov_len; \ 85 iov++; \ 86 } 87 if (fp->_flags & __SNBF) { 88 /* 89 * Unbuffered: write up to BUFSIZ bytes at a time. 90 */ 91 do { 92 GETIOV(;); 93 w = _swrite(fp, p, MIN(len, BUFSIZ)); 94 if (w <= 0) 95 goto err; 96 p += w; 97 len -= w; 98 } while ((uio->uio_resid -= w) != 0); 99 } else if ((fp->_flags & __SLBF) == 0) { 100 /* 101 * Fully buffered: fill partially full buffer, if any, 102 * and then flush. If there is no partial buffer, write 103 * one _bf._size byte chunk directly (without copying). 104 * 105 * String output is a special case: write as many bytes 106 * as fit, but pretend we wrote everything. This makes 107 * snprintf() return the number of bytes needed, rather 108 * than the number used, and avoids its write function 109 * (so that the write function can be invalid). 110 */ 111 do { 112 GETIOV(;); 113 if ((fp->_flags & (__SALC | __SSTR)) == 114 (__SALC | __SSTR) && fp->_w < len) { 115 size_t blen = fp->_p - fp->_bf._base; 116 117 /* 118 * Alloc an extra 128 bytes (+ 1 for NULL) 119 * so we don't call realloc(3) so often. 120 */ 121 fp->_w = len + 128; 122 fp->_bf._size = blen + len + 128; 123 fp->_bf._base = 124 reallocf(fp->_bf._base, fp->_bf._size + 1); 125 if (fp->_bf._base == NULL) 126 goto err; 127 fp->_p = fp->_bf._base + blen; 128 } 129 w = fp->_w; 130 if (fp->_flags & __SSTR) { 131 if (len < w) 132 w = len; 133 if (w > 0) { 134 COPY(w); /* copy MIN(fp->_w,len), */ 135 fp->_w -= w; 136 fp->_p += w; 137 } 138 w = len; /* but pretend copied all */ 139 } else if (fp->_p > fp->_bf._base && len > w) { 140 /* fill and flush */ 141 COPY(w); 142 /* fp->_w -= w; */ /* unneeded */ 143 fp->_p += w; 144 if (__fflush(fp)) 145 goto err; 146 } else if (len >= (w = fp->_bf._size)) { 147 /* write directly */ 148 w = _swrite(fp, p, w); 149 if (w <= 0) 150 goto err; 151 } else { 152 /* fill and done */ 153 w = len; 154 COPY(w); 155 fp->_w -= w; 156 fp->_p += w; 157 } 158 p += w; 159 len -= w; 160 } while ((uio->uio_resid -= w) != 0); 161 } else { 162 /* 163 * Line buffered: like fully buffered, but we 164 * must check for newlines. Compute the distance 165 * to the first newline (including the newline), 166 * or `infinity' if there is none, then pretend 167 * that the amount to write is MIN(len,nldist). 168 */ 169 nlknown = 0; 170 nldist = 0; /* XXX just to keep gcc happy */ 171 do { 172 GETIOV(nlknown = 0); 173 if (!nlknown) { 174 nl = memchr((void *)p, '\n', len); 175 nldist = nl ? nl + 1 - p : len + 1; 176 nlknown = 1; 177 } 178 s = MIN(len, nldist); 179 w = fp->_w + fp->_bf._size; 180 if (fp->_p > fp->_bf._base && s > w) { 181 COPY(w); 182 /* fp->_w -= w; */ 183 fp->_p += w; 184 if (__fflush(fp)) 185 goto err; 186 } else if (s >= (w = fp->_bf._size)) { 187 w = _swrite(fp, p, w); 188 if (w <= 0) 189 goto err; 190 } else { 191 w = s; 192 COPY(w); 193 fp->_w -= w; 194 fp->_p += w; 195 } 196 if ((nldist -= w) == 0) { 197 /* copied the newline: flush and forget */ 198 if (__fflush(fp)) 199 goto err; 200 nlknown = 0; 201 } 202 p += w; 203 len -= w; 204 } while ((uio->uio_resid -= w) != 0); 205 } 206 return (0); 207 208 err: 209 fp->_flags |= __SERR; 210 return (EOF); 211 } 212