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
bytes(FILE * fp,const char * fn,off_t off)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
lines(FILE * fp,const char * fn,off_t off)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