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 #if 0 39 static char sccsid[] = "@(#)fvwrite.c 8.1 (Berkeley) 6/4/93"; 40 #endif 41 static const char rcsid[] = 42 "$Id$"; 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include <stdio.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 register FILE *fp; 59 register struct __suio *uio; 60 { 61 register size_t len; 62 register char *p; 63 register struct __siov *iov; 64 register 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 return (EOF); 73 74 #define MIN(a, b) ((a) < (b) ? (a) : (b)) 75 #define COPY(n) (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n)) 76 77 iov = uio->uio_iov; 78 p = iov->iov_base; 79 len = iov->iov_len; 80 iov++; 81 #define GETIOV(extra_work) \ 82 while (len == 0) { \ 83 extra_work; \ 84 p = iov->iov_base; \ 85 len = iov->iov_len; \ 86 iov++; \ 87 } 88 if (fp->_flags & __SNBF) { 89 /* 90 * Unbuffered: write up to BUFSIZ bytes at a time. 91 */ 92 do { 93 GETIOV(;); 94 w = (*fp->_write)(fp->_cookie, p, MIN(len, BUFSIZ)); 95 if (w <= 0) 96 goto err; 97 p += w; 98 len -= w; 99 } while ((uio->uio_resid -= w) != 0); 100 } else if ((fp->_flags & __SLBF) == 0) { 101 /* 102 * Fully buffered: fill partially full buffer, if any, 103 * and then flush. If there is no partial buffer, write 104 * one _bf._size byte chunk directly (without copying). 105 * 106 * String output is a special case: write as many bytes 107 * as fit, but pretend we wrote everything. This makes 108 * snprintf() return the number of bytes needed, rather 109 * than the number used, and avoids its write function 110 * (so that the write function can be invalid). 111 */ 112 do { 113 GETIOV(;); 114 w = fp->_w; 115 if (fp->_flags & __SSTR) { 116 if (len < w) 117 w = len; 118 COPY(w); /* copy MIN(fp->_w,len), */ 119 fp->_w -= w; 120 fp->_p += w; 121 w = len; /* but pretend copied all */ 122 } else if (fp->_p > fp->_bf._base && len > w) { 123 /* fill and flush */ 124 COPY(w); 125 /* fp->_w -= w; */ /* unneeded */ 126 fp->_p += w; 127 if (fflush(fp)) 128 goto err; 129 } else if (len >= (w = fp->_bf._size)) { 130 /* write directly */ 131 w = (*fp->_write)(fp->_cookie, p, w); 132 if (w <= 0) 133 goto err; 134 } else { 135 /* fill and done */ 136 w = len; 137 COPY(w); 138 fp->_w -= w; 139 fp->_p += w; 140 } 141 p += w; 142 len -= w; 143 } while ((uio->uio_resid -= w) != 0); 144 } else { 145 /* 146 * Line buffered: like fully buffered, but we 147 * must check for newlines. Compute the distance 148 * to the first newline (including the newline), 149 * or `infinity' if there is none, then pretend 150 * that the amount to write is MIN(len,nldist). 151 */ 152 nlknown = 0; 153 nldist = 0; /* XXX just to keep gcc happy */ 154 do { 155 GETIOV(nlknown = 0); 156 if (!nlknown) { 157 nl = memchr((void *)p, '\n', len); 158 nldist = nl ? nl + 1 - p : len + 1; 159 nlknown = 1; 160 } 161 s = MIN(len, nldist); 162 w = fp->_w + fp->_bf._size; 163 if (fp->_p > fp->_bf._base && s > w) { 164 COPY(w); 165 /* fp->_w -= w; */ 166 fp->_p += w; 167 if (fflush(fp)) 168 goto err; 169 } else if (s >= (w = fp->_bf._size)) { 170 w = (*fp->_write)(fp->_cookie, p, w); 171 if (w <= 0) 172 goto err; 173 } else { 174 w = s; 175 COPY(w); 176 fp->_w -= w; 177 fp->_p += w; 178 } 179 if ((nldist -= w) == 0) { 180 /* copied the newline: flush and forget */ 181 if (fflush(fp)) 182 goto err; 183 nlknown = 0; 184 } 185 p += w; 186 len -= w; 187 } while ((uio->uio_resid -= w) != 0); 188 } 189 return (0); 190 191 err: 192 fp->_flags |= __SERR; 193 return (EOF); 194 } 195