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1.2 ! deraadt 1: /* $OpenBSD: read.c,v 1.4 1994/11/23 07:42:07 jtc Exp $ */
1.1 deraadt 2: /* $NetBSD: read.c,v 1.4 1994/11/23 07:42:07 jtc Exp $ */
3:
4: /*-
5: * Copyright (c) 1991, 1993
6: * The Regents of the University of California. All rights reserved.
7: *
8: * This code is derived from software contributed to Berkeley by
9: * Edward Sze-Tyan Wang.
10: *
11: * Redistribution and use in source and binary forms, with or without
12: * modification, are permitted provided that the following conditions
13: * are met:
14: * 1. Redistributions of source code must retain the above copyright
15: * notice, this list of conditions and the following disclaimer.
16: * 2. Redistributions in binary form must reproduce the above copyright
17: * notice, this list of conditions and the following disclaimer in the
18: * documentation and/or other materials provided with the distribution.
19: * 3. All advertising materials mentioning features or use of this software
20: * must display the following acknowledgement:
21: * This product includes software developed by the University of
22: * California, Berkeley and its contributors.
23: * 4. Neither the name of the University nor the names of its contributors
24: * may be used to endorse or promote products derived from this software
25: * without specific prior written permission.
26: *
27: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37: * SUCH DAMAGE.
38: */
39:
40: #ifndef lint
41: #if 0
42: static char sccsid[] = "@(#)read.c 8.1 (Berkeley) 6/6/93";
43: #endif
1.2 ! deraadt 44: static char rcsid[] = "$OpenBSD: read.c,v 1.4 1994/11/23 07:42:07 jtc Exp $";
1.1 deraadt 45: #endif /* not lint */
46:
47: #include <sys/types.h>
48: #include <sys/stat.h>
49: #include <fcntl.h>
50: #include <errno.h>
51: #include <unistd.h>
52: #include <stdio.h>
53: #include <stdlib.h>
54: #include <string.h>
55: #include "extern.h"
56:
57: /*
58: * bytes -- read bytes to an offset from the end and display.
59: *
60: * This is the function that reads to a byte offset from the end of the input,
61: * storing the data in a wrap-around buffer which is then displayed. If the
62: * rflag is set, the data is displayed in lines in reverse order, and this
63: * routine has the usual nastiness of trying to find the newlines. Otherwise,
64: * it is displayed from the character closest to the beginning of the input to
65: * the end.
66: */
67: void
68: bytes(fp, off)
69: register FILE *fp;
70: off_t off;
71: {
72: register int ch, len, tlen;
73: register char *ep, *p, *t;
74: int wrap;
75: char *sp;
76:
77: if ((sp = p = malloc(off)) == NULL)
78: err(1, "%s", strerror(errno));
79:
80: for (wrap = 0, ep = p + off; (ch = getc(fp)) != EOF;) {
81: *p = ch;
82: if (++p == ep) {
83: wrap = 1;
84: p = sp;
85: }
86: }
87: if (ferror(fp)) {
88: ierr();
89: return;
90: }
91:
92: if (rflag) {
93: for (t = p - 1, len = 0; t >= sp; --t, ++len)
94: if (*t == '\n' && len) {
95: WR(t + 1, len);
96: len = 0;
97: }
98: if (wrap) {
99: tlen = len;
100: for (t = ep - 1, len = 0; t >= p; --t, ++len)
101: if (*t == '\n') {
102: if (len) {
103: WR(t + 1, len);
104: len = 0;
105: }
106: if (tlen) {
107: WR(sp, tlen);
108: tlen = 0;
109: }
110: }
111: if (len)
112: WR(t + 1, len);
113: if (tlen)
114: WR(sp, tlen);
115: }
116: } else {
117: if (wrap && (len = ep - p))
118: WR(p, len);
119: if (len = p - sp)
120: WR(sp, len);
121: }
122: }
123:
124: /*
125: * lines -- read lines to an offset from the end and display.
126: *
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
132: * the end.
133: */
134: void
135: lines(fp, off)
136: register FILE *fp;
137: off_t off;
138: {
139: struct {
140: u_int blen;
141: u_int len;
142: char *l;
143: } *lines;
144: register int ch;
145: register char *p;
146: int blen, cnt, recno, wrap;
147: char *sp;
148:
149: if ((lines = malloc(off * sizeof(*lines))) == NULL)
150: err(1, "%s", strerror(errno));
151:
152: sp = NULL;
153: blen = cnt = recno = wrap = 0;
154:
155: while ((ch = getc(fp)) != EOF) {
156: if (++cnt > blen) {
157: if ((sp = realloc(sp, blen += 1024)) == NULL)
158: err(1, "%s", strerror(errno));
159: p = sp + cnt - 1;
160: }
161: *p++ = ch;
162: if (ch == '\n') {
163: if (lines[recno].blen < cnt) {
164: lines[recno].blen = cnt + 256;
165: if ((lines[recno].l = realloc(lines[recno].l,
166: lines[recno].blen)) == NULL)
167: err(1, "%s", strerror(errno));
168: }
169: bcopy(sp, lines[recno].l, lines[recno].len = cnt);
170: cnt = 0;
171: p = sp;
172: if (++recno == off) {
173: wrap = 1;
174: recno = 0;
175: }
176: }
177: }
178: if (ferror(fp)) {
179: ierr();
180: return;
181: }
182: if (cnt) {
183: lines[recno].l = sp;
184: lines[recno].len = cnt;
185: if (++recno == off) {
186: wrap = 1;
187: recno = 0;
188: }
189: }
190:
191: if (rflag) {
192: for (cnt = recno - 1; cnt >= 0; --cnt)
193: WR(lines[cnt].l, lines[cnt].len);
194: if (wrap)
195: for (cnt = off - 1; cnt >= recno; --cnt)
196: WR(lines[cnt].l, lines[cnt].len);
197: } else {
198: if (wrap)
199: for (cnt = recno; cnt < off; ++cnt)
200: WR(lines[cnt].l, lines[cnt].len);
201: for (cnt = 0; cnt < recno; ++cnt)
202: WR(lines[cnt].l, lines[cnt].len);
203: }
204: }