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