1*d5250e4eSitojun /* $NetBSD: read.c,v 1.10 2003/10/16 06:39:56 itojun Exp $ */ 2ae646d0eSjtc 3aa97860fSglass /*- 4ae646d0eSjtc * Copyright (c) 1991, 1993 5ae646d0eSjtc * The Regents of the University of California. All rights reserved. 6aa97860fSglass * 7aa97860fSglass * This code is derived from software contributed to Berkeley by 8aa97860fSglass * Edward Sze-Tyan Wang. 9aa97860fSglass * 10aa97860fSglass * Redistribution and use in source and binary forms, with or without 11aa97860fSglass * modification, are permitted provided that the following conditions 12aa97860fSglass * are met: 13aa97860fSglass * 1. Redistributions of source code must retain the above copyright 14aa97860fSglass * notice, this list of conditions and the following disclaimer. 15aa97860fSglass * 2. Redistributions in binary form must reproduce the above copyright 16aa97860fSglass * notice, this list of conditions and the following disclaimer in the 17aa97860fSglass * documentation and/or other materials provided with the distribution. 1889aaa1bbSagc * 3. Neither the name of the University nor the names of its contributors 19aa97860fSglass * may be used to endorse or promote products derived from this software 20aa97860fSglass * without specific prior written permission. 21aa97860fSglass * 22aa97860fSglass * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23aa97860fSglass * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24aa97860fSglass * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25aa97860fSglass * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26aa97860fSglass * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27aa97860fSglass * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28aa97860fSglass * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29aa97860fSglass * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30aa97860fSglass * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31aa97860fSglass * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32aa97860fSglass * SUCH DAMAGE. 33aa97860fSglass */ 34aa97860fSglass 35079884daSlukem #include <sys/cdefs.h> 36aa97860fSglass #ifndef lint 37ae646d0eSjtc #if 0 38ae646d0eSjtc static char sccsid[] = "@(#)read.c 8.1 (Berkeley) 6/6/93"; 39ae646d0eSjtc #endif 40*d5250e4eSitojun __RCSID("$NetBSD: read.c,v 1.10 2003/10/16 06:39:56 itojun Exp $"); 41aa97860fSglass #endif /* not lint */ 42aa97860fSglass 43aa97860fSglass #include <sys/types.h> 44aa97860fSglass #include <sys/stat.h> 45aa97860fSglass #include <fcntl.h> 46aa97860fSglass #include <errno.h> 47aa97860fSglass #include <unistd.h> 48aa97860fSglass #include <stdio.h> 49aa97860fSglass #include <stdlib.h> 50aa97860fSglass #include <string.h> 51aa97860fSglass #include "extern.h" 52aa97860fSglass 53aa97860fSglass /* 54aa97860fSglass * bytes -- read bytes to an offset from the end and display. 55aa97860fSglass * 56aa97860fSglass * This is the function that reads to a byte offset from the end of the input, 57aa97860fSglass * storing the data in a wrap-around buffer which is then displayed. If the 58aa97860fSglass * rflag is set, the data is displayed in lines in reverse order, and this 59aa97860fSglass * routine has the usual nastiness of trying to find the newlines. Otherwise, 60aa97860fSglass * it is displayed from the character closest to the beginning of the input to 61aa97860fSglass * the end. 62b02d8140Scgd * 63b02d8140Scgd * Non-zero return means than a (non-fatal) error occurred. 64aa97860fSglass */ 65b02d8140Scgd int 663c4c9d2bSwiz bytes(FILE *fp, __off_t off) 67aa97860fSglass { 68079884daSlukem int ch, len, tlen; 69079884daSlukem char *ep, *p, *t; 70aa97860fSglass int wrap; 71aa97860fSglass char *sp; 72aa97860fSglass 73aa97860fSglass if ((sp = p = malloc(off)) == NULL) 74ae646d0eSjtc err(1, "%s", strerror(errno)); 75aa97860fSglass 76aa97860fSglass for (wrap = 0, ep = p + off; (ch = getc(fp)) != EOF;) { 77aa97860fSglass *p = ch; 78aa97860fSglass if (++p == ep) { 79aa97860fSglass wrap = 1; 80aa97860fSglass p = sp; 81aa97860fSglass } 82aa97860fSglass } 83ae646d0eSjtc if (ferror(fp)) { 84aa97860fSglass ierr(); 85b02d8140Scgd return (1); 86ae646d0eSjtc } 87aa97860fSglass 88aa97860fSglass if (rflag) { 89aa97860fSglass for (t = p - 1, len = 0; t >= sp; --t, ++len) 90aa97860fSglass if (*t == '\n' && len) { 91aa97860fSglass WR(t + 1, len); 92aa97860fSglass len = 0; 93aa97860fSglass } 94aa97860fSglass if (wrap) { 95aa97860fSglass tlen = len; 96aa97860fSglass for (t = ep - 1, len = 0; t >= p; --t, ++len) 97aa97860fSglass if (*t == '\n') { 98aa97860fSglass if (len) { 99aa97860fSglass WR(t + 1, len); 100aa97860fSglass len = 0; 101aa97860fSglass } 102aa97860fSglass if (tlen) { 103aa97860fSglass WR(sp, tlen); 104aa97860fSglass tlen = 0; 105aa97860fSglass } 106aa97860fSglass } 107aa97860fSglass if (len) 108aa97860fSglass WR(t + 1, len); 109aa97860fSglass if (tlen) 110aa97860fSglass WR(sp, tlen); 111aa97860fSglass } 112aa97860fSglass } else { 113aa97860fSglass if (wrap && (len = ep - p)) 114aa97860fSglass WR(p, len); 115079884daSlukem if ((len = p - sp) == 0) 116aa97860fSglass WR(sp, len); 117aa97860fSglass } 118b02d8140Scgd return (0); 119aa97860fSglass } 120aa97860fSglass 121aa97860fSglass /* 122aa97860fSglass * lines -- read lines to an offset from the end and display. 123aa97860fSglass * 124aa97860fSglass * This is the function that reads to a line offset from the end of the input, 125aa97860fSglass * storing the data in an array of buffers which is then displayed. If the 126aa97860fSglass * rflag is set, the data is displayed in lines in reverse order, and this 127aa97860fSglass * routine has the usual nastiness of trying to find the newlines. Otherwise, 128aa97860fSglass * it is displayed from the line closest to the beginning of the input to 129aa97860fSglass * the end. 130b02d8140Scgd * 131b02d8140Scgd * Non-zero return means than a (non-fatal) error occurred. 132aa97860fSglass */ 133b02d8140Scgd int 1343c4c9d2bSwiz lines(FILE *fp, __off_t off) 135aa97860fSglass { 136aa97860fSglass struct { 137aa97860fSglass u_int blen; 138aa97860fSglass u_int len; 139aa97860fSglass char *l; 140aa97860fSglass } *lines; 141079884daSlukem int ch; 142079884daSlukem char *p; 143ae646d0eSjtc int blen, cnt, recno, wrap; 144*d5250e4eSitojun char *sp, *n; 145aa97860fSglass 146079884daSlukem p = NULL; 147aa97860fSglass if ((lines = malloc(off * sizeof(*lines))) == NULL) 148ae646d0eSjtc err(1, "%s", strerror(errno)); 149aa97860fSglass 1507872ac63Schristos memset(lines, 0, sizeof(*lines) * off); 1517872ac63Schristos 152aa97860fSglass sp = NULL; 153aa97860fSglass blen = cnt = recno = wrap = 0; 154aa97860fSglass 155aa97860fSglass while ((ch = getc(fp)) != EOF) { 156aa97860fSglass if (++cnt > blen) { 157*d5250e4eSitojun if ((n = realloc(sp, blen + 1024)) == NULL) 158ae646d0eSjtc err(1, "%s", strerror(errno)); 159*d5250e4eSitojun sp = n; 160*d5250e4eSitojun blen += 1024; 161aa97860fSglass p = sp + cnt - 1; 162aa97860fSglass } 163aa97860fSglass *p++ = ch; 164aa97860fSglass if (ch == '\n') { 165aa97860fSglass if (lines[recno].blen < cnt) { 166*d5250e4eSitojun if ((n = realloc(lines[recno].l, 167*d5250e4eSitojun cnt + 256)) == NULL) 168ae646d0eSjtc err(1, "%s", strerror(errno)); 169*d5250e4eSitojun lines[recno].l = n; 170*d5250e4eSitojun lines[recno].blen = cnt + 256; 171aa97860fSglass } 172079884daSlukem memmove(lines[recno].l, sp, lines[recno].len = cnt); 173aa97860fSglass cnt = 0; 174aa97860fSglass p = sp; 175aa97860fSglass if (++recno == off) { 176aa97860fSglass wrap = 1; 177aa97860fSglass recno = 0; 178aa97860fSglass } 179aa97860fSglass } 180aa97860fSglass } 181ae646d0eSjtc if (ferror(fp)) { 182aa97860fSglass ierr(); 183b02d8140Scgd return (1); 184ae646d0eSjtc } 185aa97860fSglass if (cnt) { 186aa97860fSglass lines[recno].l = sp; 187aa97860fSglass lines[recno].len = cnt; 188aa97860fSglass if (++recno == off) { 189aa97860fSglass wrap = 1; 190aa97860fSglass recno = 0; 191aa97860fSglass } 192aa97860fSglass } 193aa97860fSglass 194aa97860fSglass if (rflag) { 195aa97860fSglass for (cnt = recno - 1; cnt >= 0; --cnt) 196aa97860fSglass WR(lines[cnt].l, lines[cnt].len); 197aa97860fSglass if (wrap) 198aa97860fSglass for (cnt = off - 1; cnt >= recno; --cnt) 199aa97860fSglass WR(lines[cnt].l, lines[cnt].len); 200aa97860fSglass } else { 201aa97860fSglass if (wrap) 202aa97860fSglass for (cnt = recno; cnt < off; ++cnt) 203aa97860fSglass WR(lines[cnt].l, lines[cnt].len); 204aa97860fSglass for (cnt = 0; cnt < recno; ++cnt) 205aa97860fSglass WR(lines[cnt].l, lines[cnt].len); 206aa97860fSglass } 207b02d8140Scgd return (0); 208aa97860fSglass } 209