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 #ifndef lint 37 static const char sccsid[] = "@(#)read.c 8.1 (Berkeley) 6/6/93"; 38 #endif 39 40 #include <sys/types.h> 41 #include <sys/stat.h> 42 43 #include <err.h> 44 #include <errno.h> 45 #include <fcntl.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <unistd.h> 50 51 #include <libcasper.h> 52 #include <casper/cap_fileargs.h> 53 54 #include "extern.h" 55 56 /* 57 * bytes -- read bytes to an offset from the end and display. 58 * 59 * This is the function that reads to a byte offset from the end of the input, 60 * storing the data in a wrap-around buffer which is then displayed. If the 61 * rflag is set, the data is displayed in lines in reverse order, and this 62 * routine has the usual nastiness of trying to find the newlines. Otherwise, 63 * it is displayed from the character closest to the beginning of the input to 64 * the end. 65 */ 66 int 67 bytes(FILE *fp, const char *fn, off_t off) 68 { 69 int ch, len, tlen; 70 char *ep, *p, *t; 71 int wrap; 72 char *sp; 73 74 if ((sp = p = malloc(off)) == NULL) 75 err(1, "malloc"); 76 77 for (wrap = 0, ep = p + off; (ch = getc(fp)) != EOF;) { 78 *p = ch; 79 if (++p == ep) { 80 wrap = 1; 81 p = sp; 82 } 83 } 84 if (ferror(fp)) { 85 ierr(fn); 86 free(sp); 87 return 1; 88 } 89 90 if (rflag) { 91 for (t = p - 1, len = 0; t >= sp; --t, ++len) 92 if (*t == '\n' && len) { 93 WR(t + 1, len); 94 len = 0; 95 } 96 if (wrap) { 97 tlen = len; 98 for (t = ep - 1, len = 0; t >= p; --t, ++len) 99 if (*t == '\n') { 100 if (len) { 101 WR(t + 1, len); 102 len = 0; 103 } 104 if (tlen) { 105 WR(sp, tlen); 106 tlen = 0; 107 } 108 } 109 if (len) 110 WR(t + 1, len); 111 if (tlen) 112 WR(sp, tlen); 113 } 114 } else { 115 if (wrap && (len = ep - p)) 116 WR(p, len); 117 len = p - sp; 118 if (len) 119 WR(sp, len); 120 } 121 122 free(sp); 123 return 0; 124 } 125 126 /* 127 * lines -- read lines to an offset from the end and display. 128 * 129 * This is the function that reads to a line offset from the end of the input, 130 * storing the data in an array of buffers which is then displayed. If the 131 * rflag is set, the data is displayed in lines in reverse order, and this 132 * routine has the usual nastiness of trying to find the newlines. Otherwise, 133 * it is displayed from the line closest to the beginning of the input to 134 * the end. 135 */ 136 int 137 lines(FILE *fp, const char *fn, off_t off) 138 { 139 struct { 140 int blen; 141 u_int len; 142 char *l; 143 } *llines; 144 int ch, rc; 145 char *p, *sp; 146 int blen, cnt, recno, wrap; 147 148 if ((llines = calloc(off, sizeof(*llines))) == NULL) 149 err(1, "calloc"); 150 p = sp = NULL; 151 blen = cnt = recno = wrap = 0; 152 rc = 0; 153 154 while ((ch = getc(fp)) != EOF) { 155 if (++cnt > blen) { 156 if ((sp = realloc(sp, blen += 1024)) == NULL) 157 err(1, "realloc"); 158 p = sp + cnt - 1; 159 } 160 *p++ = ch; 161 if (ch == '\n') { 162 if ((int)llines[recno].blen < cnt) { 163 llines[recno].blen = cnt + 256; 164 if ((llines[recno].l = realloc(llines[recno].l, 165 llines[recno].blen)) == NULL) 166 err(1, "realloc"); 167 } 168 bcopy(sp, llines[recno].l, llines[recno].len = cnt); 169 cnt = 0; 170 p = sp; 171 if (++recno == off) { 172 wrap = 1; 173 recno = 0; 174 } 175 } 176 } 177 if (ferror(fp)) { 178 ierr(fn); 179 rc = 1; 180 goto done; 181 } 182 if (cnt) { 183 llines[recno].l = sp; 184 sp = NULL; 185 llines[recno].len = cnt; 186 if (++recno == off) { 187 wrap = 1; 188 recno = 0; 189 } 190 } 191 192 if (rflag) { 193 for (cnt = recno - 1; cnt >= 0; --cnt) 194 WR(llines[cnt].l, llines[cnt].len); 195 if (wrap) 196 for (cnt = off - 1; cnt >= recno; --cnt) 197 WR(llines[cnt].l, llines[cnt].len); 198 } else { 199 if (wrap) 200 for (cnt = recno; cnt < off; ++cnt) 201 WR(llines[cnt].l, llines[cnt].len); 202 for (cnt = 0; cnt < recno; ++cnt) 203 WR(llines[cnt].l, llines[cnt].len); 204 } 205 done: 206 for (cnt = 0; cnt < off; cnt++) 207 free(llines[cnt].l); 208 free(sp); 209 free(llines); 210 return (rc); 211 } 212