2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
6 * Edward Sze-Tyan Wang.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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.
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
33 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
38 static const char sccsid[] = "@(#)read.c 8.1 (Berkeley) 6/6/93";
41 #include <sys/types.h>
55 * bytes -- read bytes to an offset from the end and display.
57 * This is the function that reads to a byte offset from the end of the input,
58 * storing the data in a wrap-around buffer which is then displayed. If the
59 * rflag is set, the data is displayed in lines in reverse order, and this
60 * routine has the usual nastiness of trying to find the newlines. Otherwise,
61 * it is displayed from the character closest to the beginning of the input to
65 bytes(FILE *fp, const char *fn, off_t off)
72 if ((sp = p = malloc(off)) == NULL)
75 for (wrap = 0, ep = p + off; (ch = getc(fp)) != EOF;) {
89 for (t = p - 1, len = 0; t >= sp; --t, ++len)
90 if (*t == '\n' && len) {
96 for (t = ep - 1, len = 0; t >= p; --t, ++len)
113 if (wrap && (len = ep - p))
125 * lines -- read lines to an offset from the end and display.
127 * This is the function that reads to a line offset from the end of the input,
128 * storing the data in an array of buffers which is then displayed. If the
129 * rflag is set, the data is displayed in lines in reverse order, and this
130 * routine has the usual nastiness of trying to find the newlines. Otherwise,
131 * it is displayed from the line closest to the beginning of the input to
135 lines(FILE *fp, const char *fn, off_t off)
144 int blen, cnt, recno, wrap;
146 if ((llines = calloc(off, sizeof(*llines))) == NULL)
149 blen = cnt = recno = wrap = 0;
152 while ((ch = getc(fp)) != EOF) {
154 if ((sp = realloc(sp, blen += 1024)) == NULL)
160 if ((int)llines[recno].blen < cnt) {
161 llines[recno].blen = cnt + 256;
162 if ((llines[recno].l = realloc(llines[recno].l,
163 llines[recno].blen)) == NULL)
166 bcopy(sp, llines[recno].l, llines[recno].len = cnt);
169 if (++recno == off) {
181 llines[recno].l = sp;
183 llines[recno].len = cnt;
184 if (++recno == off) {
191 for (cnt = recno - 1; cnt >= 0; --cnt)
192 WR(llines[cnt].l, llines[cnt].len);
194 for (cnt = off - 1; cnt >= recno; --cnt)
195 WR(llines[cnt].l, llines[cnt].len);
198 for (cnt = recno; cnt < off; ++cnt)
199 WR(llines[cnt].l, llines[cnt].len);
200 for (cnt = 0; cnt < recno; ++cnt)
201 WR(llines[cnt].l, llines[cnt].len);
204 for (cnt = 0; cnt < off; cnt++)