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 41 #include <stdio.h> 42 #include <string.h> 43 #include "local.h" 44 #include "fvwrite.h" 45 46 /* 47 * Write some memory regions. Return zero on success, EOF on error. 48 * 49 * This routine is large and unsightly, but most of the ugliness due 50 * to the three different kinds of output buffering is handled here. 51 */ 52 __sfvwrite(fp, uio) 53 register FILE *fp; 54 register struct __suio *uio; 55 { 56 register size_t len; 57 register char *p; 58 register struct __siov *iov; 59 register int w, s; 60 char *nl; 61 int nlknown, nldist; 62 63 if ((len = uio->uio_resid) == 0) 64 return (0); 65 /* make sure we can write */ 66 if (cantwrite(fp)) 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 = (*fp->_write)(fp->_cookie, 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 w = fp->_w; 110 if (fp->_flags & __SSTR) { 111 if (len < w) 112 w = len; 113 COPY(w); /* copy MIN(fp->_w,len), */ 114 fp->_w -= w; 115 fp->_p += w; 116 w = len; /* but pretend copied all */ 117 } else if (fp->_p > fp->_bf._base && len > w) { 118 /* fill and flush */ 119 COPY(w); 120 /* fp->_w -= w; */ /* unneeded */ 121 fp->_p += w; 122 if (fflush(fp)) 123 goto err; 124 } else if (len >= (w = fp->_bf._size)) { 125 /* write directly */ 126 w = (*fp->_write)(fp->_cookie, p, w); 127 if (w <= 0) 128 goto err; 129 } else { 130 /* fill and done */ 131 w = len; 132 COPY(w); 133 fp->_w -= w; 134 fp->_p += w; 135 } 136 p += w; 137 len -= w; 138 } while ((uio->uio_resid -= w) != 0); 139 } else { 140 /* 141 * Line buffered: like fully buffered, but we 142 * must check for newlines. Compute the distance 143 * to the first newline (including the newline), 144 * or `infinity' if there is none, then pretend 145 * that the amount to write is MIN(len,nldist). 146 */ 147 nlknown = 0; 148 nldist = 0; /* XXX just to keep gcc happy */ 149 do { 150 GETIOV(nlknown = 0); 151 if (!nlknown) { 152 nl = memchr((void *)p, '\n', len); 153 nldist = nl ? nl + 1 - p : len + 1; 154 nlknown = 1; 155 } 156 s = MIN(len, nldist); 157 w = fp->_w + fp->_bf._size; 158 if (fp->_p > fp->_bf._base && s > w) { 159 COPY(w); 160 /* fp->_w -= w; */ 161 fp->_p += w; 162 if (fflush(fp)) 163 goto err; 164 } else if (s >= (w = fp->_bf._size)) { 165 w = (*fp->_write)(fp->_cookie, p, w); 166 if (w <= 0) 167 goto err; 168 } else { 169 w = s; 170 COPY(w); 171 fp->_w -= w; 172 fp->_p += w; 173 } 174 if ((nldist -= w) == 0) { 175 /* copied the newline: flush and forget */ 176 if (fflush(fp)) 177 goto err; 178 nlknown = 0; 179 } 180 p += w; 181 len -= w; 182 } while ((uio->uio_resid -= w) != 0); 183 } 184 return (0); 185 186 err: 187 fp->_flags |= __SERR; 188 return (EOF); 189 } 190