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
bytes(FILE * fp,const char * fn,off_t off)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, "failed to allocate memory");
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
lines(FILE * fp,const char * fn,off_t off)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, "failed to allocate memory");
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, "failed to allocate memory");
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, "failed to allocate memory");
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