1 /* 2 * Copyright (c) 1991, 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 * Edward Sze-Tyan Wang. 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 * 4. 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 #include <sys/types.h> 34 #include <sys/stat.h> 35 #include <sys/mman.h> 36 37 #include <err.h> 38 #include <errno.h> 39 #include <stdio.h> 40 #include <stdlib.h> 41 #include <string.h> 42 #include <unistd.h> 43 44 #include "extern.h" 45 46 void 47 ierr(const char *fname) 48 { 49 warn("%s", fname); 50 rval = 1; 51 } 52 53 void 54 oerr(void) 55 { 56 err(1, "stdout"); 57 } 58 59 /* 60 * Print `len' bytes from the file associated with `mip', starting at 61 * absolute file offset `startoff'. May move map window. 62 */ 63 int 64 mapprint(struct mapinfo *mip, off_t startoff, off_t len) 65 { 66 int n; 67 68 while (len > 0) { 69 if (startoff < mip->mapoff || startoff >= mip->mapoff + 70 (off_t)mip->maplen) { 71 if (maparound(mip, startoff) != 0) 72 return (1); 73 } 74 n = (mip->mapoff + mip->maplen) - startoff; 75 if (n > len) 76 n = len; 77 WR(mip->start + (startoff - mip->mapoff), n); 78 startoff += n; 79 len -= n; 80 } 81 return (0); 82 } 83 84 /* 85 * Move the map window so that it contains the byte at absolute file 86 * offset `offset'. The start of the map window will be TAILMAPLEN 87 * aligned. 88 */ 89 int 90 maparound(struct mapinfo *mip, off_t offset) 91 { 92 93 if (mip->start != NULL && munmap(mip->start, mip->maplen) != 0) 94 return (1); 95 96 mip->mapoff = offset & ~((off_t)TAILMAPLEN - 1); 97 mip->maplen = TAILMAPLEN; 98 if ((off_t)mip->maplen > mip->maxoff - mip->mapoff) 99 mip->maplen = mip->maxoff - mip->mapoff; 100 if (mip->maplen == 0) 101 abort(); 102 if ((mip->start = mmap(NULL, mip->maplen, PROT_READ, MAP_SHARED, 103 mip->fd, mip->mapoff)) == MAP_FAILED) 104 return (1); 105 106 return (0); 107 } 108