1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Edward Sze-Tyan Wang. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 37 __FBSDID("$FreeBSD$"); 38 39 #ifndef lint 40 static const char sccsid[] = "@(#)read.c 8.1 (Berkeley) 6/6/93"; 41 #endif 42 43 #include <sys/types.h> 44 #include <sys/stat.h> 45 46 #include <err.h> 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 54 #include <libcasper.h> 55 #include <casper/cap_fileargs.h> 56 57 #include "extern.h" 58 59 /* 60 * bytes -- read bytes to an offset from the end and display. 61 * 62 * This is the function that reads to a byte offset from the end of the input, 63 * storing the data in a wrap-around buffer which is then displayed. If the 64 * rflag is set, the data is displayed in lines in reverse order, and this 65 * routine has the usual nastiness of trying to find the newlines. Otherwise, 66 * it is displayed from the character closest to the beginning of the input to 67 * the end. 68 */ 69 int 70 bytes(FILE *fp, const char *fn, off_t off) 71 { 72 int ch, len, tlen; 73 char *ep, *p, *t; 74 int wrap; 75 char *sp; 76 77 if ((sp = p = malloc(off)) == NULL) 78 err(1, "malloc"); 79 80 for (wrap = 0, ep = p + off; (ch = getc(fp)) != EOF;) { 81 *p = ch; 82 if (++p == ep) { 83 wrap = 1; 84 p = sp; 85 } 86 } 87 if (ferror(fp)) { 88 ierr(fn); 89 free(sp); 90 return 1; 91 } 92 93 if (rflag) { 94 for (t = p - 1, len = 0; t >= sp; --t, ++len) 95 if (*t == '\n' && len) { 96 WR(t + 1, len); 97 len = 0; 98 } 99 if (wrap) { 100 tlen = len; 101 for (t = ep - 1, len = 0; t >= p; --t, ++len) 102 if (*t == '\n') { 103 if (len) { 104 WR(t + 1, len); 105 len = 0; 106 } 107 if (tlen) { 108 WR(sp, tlen); 109 tlen = 0; 110 } 111 } 112 if (len) 113 WR(t + 1, len); 114 if (tlen) 115 WR(sp, tlen); 116 } 117 } else { 118 if (wrap && (len = ep - p)) 119 WR(p, len); 120 len = p - sp; 121 if (len) 122 WR(sp, len); 123 } 124 125 free(sp); 126 return 0; 127 } 128 129 /* 130 * lines -- read lines to an offset from the end and display. 131 * 132 * This is the function that reads to a line offset from the end of the input, 133 * storing the data in an array of buffers which is then displayed. If the 134 * rflag is set, the data is displayed in lines in reverse order, and this 135 * routine has the usual nastiness of trying to find the newlines. Otherwise, 136 * it is displayed from the line closest to the beginning of the input to 137 * the end. 138 */ 139 int 140 lines(FILE *fp, const char *fn, off_t off) 141 { 142 struct { 143 int blen; 144 u_int len; 145 char *l; 146 } *llines; 147 int ch, rc; 148 char *p, *sp; 149 int blen, cnt, recno, wrap; 150 151 if ((llines = calloc(off, sizeof(*llines))) == NULL) 152 err(1, "calloc"); 153 p = sp = NULL; 154 blen = cnt = recno = wrap = 0; 155 rc = 0; 156 157 while ((ch = getc(fp)) != EOF) { 158 if (++cnt > blen) { 159 if ((sp = realloc(sp, blen += 1024)) == NULL) 160 err(1, "realloc"); 161 p = sp + cnt - 1; 162 } 163 *p++ = ch; 164 if (ch == '\n') { 165 if ((int)llines[recno].blen < cnt) { 166 llines[recno].blen = cnt + 256; 167 if ((llines[recno].l = realloc(llines[recno].l, 168 llines[recno].blen)) == NULL) 169 err(1, "realloc"); 170 } 171 bcopy(sp, llines[recno].l, llines[recno].len = cnt); 172 cnt = 0; 173 p = sp; 174 if (++recno == off) { 175 wrap = 1; 176 recno = 0; 177 } 178 } 179 } 180 if (ferror(fp)) { 181 ierr(fn); 182 rc = 1; 183 goto done; 184 } 185 if (cnt) { 186 llines[recno].l = sp; 187 sp = NULL; 188 llines[recno].len = cnt; 189 if (++recno == off) { 190 wrap = 1; 191 recno = 0; 192 } 193 } 194 195 if (rflag) { 196 for (cnt = recno - 1; cnt >= 0; --cnt) 197 WR(llines[cnt].l, llines[cnt].len); 198 if (wrap) 199 for (cnt = off - 1; cnt >= recno; --cnt) 200 WR(llines[cnt].l, llines[cnt].len); 201 } else { 202 if (wrap) 203 for (cnt = recno; cnt < off; ++cnt) 204 WR(llines[cnt].l, llines[cnt].len); 205 for (cnt = 0; cnt < recno; ++cnt) 206 WR(llines[cnt].l, llines[cnt].len); 207 } 208 done: 209 for (cnt = 0; cnt < off; cnt++) 210 free(llines[cnt].l); 211 free(sp); 212 free(llines); 213 return (rc); 214 } 215