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 36 37 #include <sys/types.h> 38 #include <sys/stat.h> 39 40 #include <err.h> 41 #include <errno.h> 42 #include <fcntl.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <unistd.h> 47 48 #include <libcasper.h> 49 #include <casper/cap_fileargs.h> 50 51 #include "extern.h" 52 53 /* 54 * bytes -- read bytes to an offset from the end and display. 55 * 56 * This is the function that reads to a byte offset from the end of the input, 57 * storing the data in a wrap-around buffer which is then displayed. If the 58 * rflag is set, the data is displayed in lines in reverse order, and this 59 * routine has the usual nastiness of trying to find the newlines. Otherwise, 60 * it is displayed from the character closest to the beginning of the input to 61 * the end. 62 */ 63 int 64 bytes(FILE *fp, const char *fn, off_t off) 65 { 66 int ch, len, tlen; 67 char *ep, *p, *t; 68 int wrap; 69 char *sp; 70 71 if ((sp = p = malloc(off)) == NULL) 72 err(1, "failed to allocate memory"); 73 74 for (wrap = 0, ep = p + off; (ch = getc(fp)) != EOF;) { 75 *p = ch; 76 if (++p == ep) { 77 wrap = 1; 78 p = sp; 79 } 80 } 81 if (ferror(fp)) { 82 ierr(fn); 83 free(sp); 84 return 1; 85 } 86 87 if (rflag) { 88 for (t = p - 1, len = 0; t >= sp; --t, ++len) 89 if (*t == '\n' && len) { 90 WR(t + 1, len); 91 len = 0; 92 } 93 if (wrap) { 94 tlen = len; 95 for (t = ep - 1, len = 0; t >= p; --t, ++len) 96 if (*t == '\n') { 97 if (len) { 98 WR(t + 1, len); 99 len = 0; 100 } 101 if (tlen) { 102 WR(sp, tlen); 103 tlen = 0; 104 } 105 } 106 if (len) 107 WR(t + 1, len); 108 if (tlen) 109 WR(sp, tlen); 110 } 111 } else { 112 if (wrap && (len = ep - p)) 113 WR(p, len); 114 len = p - sp; 115 if (len) 116 WR(sp, len); 117 } 118 119 free(sp); 120 return 0; 121 } 122 123 /* 124 * lines -- read lines to an offset from the end and display. 125 * 126 * This is the function that reads to a line offset from the end of the input, 127 * storing the data in an array of buffers which is then displayed. If the 128 * rflag is set, the data is displayed in lines in reverse order, and this 129 * routine has the usual nastiness of trying to find the newlines. Otherwise, 130 * it is displayed from the line closest to the beginning of the input to 131 * the end. 132 */ 133 int 134 lines(FILE *fp, const char *fn, off_t off) 135 { 136 struct { 137 int blen; 138 u_int len; 139 char *l; 140 } *llines; 141 int ch, rc; 142 char *p, *sp; 143 int blen, cnt, recno, wrap; 144 145 if ((llines = calloc(off, sizeof(*llines))) == NULL) 146 err(1, "failed to allocate memory"); 147 p = sp = NULL; 148 blen = cnt = recno = wrap = 0; 149 rc = 0; 150 151 while ((ch = getc(fp)) != EOF) { 152 if (++cnt > blen) { 153 if ((sp = realloc(sp, blen += 1024)) == NULL) 154 err(1, "failed to allocate memory"); 155 p = sp + cnt - 1; 156 } 157 *p++ = ch; 158 if (ch == '\n') { 159 if ((int)llines[recno].blen < cnt) { 160 llines[recno].blen = cnt + 256; 161 if ((llines[recno].l = realloc(llines[recno].l, 162 llines[recno].blen)) == NULL) 163 err(1, "failed to allocate memory"); 164 } 165 bcopy(sp, llines[recno].l, llines[recno].len = cnt); 166 cnt = 0; 167 p = sp; 168 if (++recno == off) { 169 wrap = 1; 170 recno = 0; 171 } 172 } 173 } 174 if (ferror(fp)) { 175 ierr(fn); 176 rc = 1; 177 goto done; 178 } 179 if (cnt) { 180 llines[recno].l = sp; 181 sp = NULL; 182 llines[recno].len = cnt; 183 if (++recno == off) { 184 wrap = 1; 185 recno = 0; 186 } 187 } 188 189 if (rflag) { 190 for (cnt = recno - 1; cnt >= 0; --cnt) 191 WR(llines[cnt].l, llines[cnt].len); 192 if (wrap) 193 for (cnt = off - 1; cnt >= recno; --cnt) 194 WR(llines[cnt].l, llines[cnt].len); 195 } else { 196 if (wrap) 197 for (cnt = recno; cnt < off; ++cnt) 198 WR(llines[cnt].l, llines[cnt].len); 199 for (cnt = 0; cnt < recno; ++cnt) 200 WR(llines[cnt].l, llines[cnt].len); 201 } 202 done: 203 for (cnt = 0; cnt < off; cnt++) 204 free(llines[cnt].l); 205 free(sp); 206 free(llines); 207 return (rc); 208 } 209