1/* buf.c: This file contains the scratch-file buffer routines for the
2   ed line editor. */
3/*-
4 * Copyright (c) 1993 Andrew Moore, Talke Studio.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include <sys/file.h>
33#include <sys/stat.h>
34
35#include "ed.h"
36
37
38static FILE *sfp;			/* scratch file pointer */
39static off_t sfseek;			/* scratch file position */
40static int seek_write;			/* seek before writing */
41static line_t buffer_head;		/* incore buffer */
42
43/* get_sbuf_line: get a line of text from the scratch file; return pointer
44   to the text */
45char *
46get_sbuf_line(line_t *lp)
47{
48	static char *sfbuf = NULL;	/* buffer */
49	static int sfbufsz = 0;		/* buffer size */
50
51	int len, ct;
52
53	if (lp == &buffer_head)
54		return NULL;
55	seek_write = 1;				/* force seek on write */
56	/* out of position */
57	if (sfseek != lp->seek) {
58		sfseek = lp->seek;
59		if (fseeko(sfp, sfseek, SEEK_SET) < 0) {
60			fprintf(stderr, "%s\n", strerror(errno));
61			errmsg = "cannot seek temp file";
62			return NULL;
63		}
64	}
65	len = lp->len;
66	REALLOC(sfbuf, sfbufsz, len + 1, NULL);
67	if ((ct = fread(sfbuf, sizeof(char), len, sfp)) <  0 || ct != len) {
68		fprintf(stderr, "%s\n", strerror(errno));
69		errmsg = "cannot read temp file";
70		return NULL;
71	}
72	sfseek += len;				/* update file position */
73	sfbuf[len] = '\0';
74	return sfbuf;
75}
76
77
78/* put_sbuf_line: write a line of text to the scratch file and add a line node
79   to the editor buffer;  return a pointer to the end of the text */
80const char *
81put_sbuf_line(const char *cs)
82{
83	line_t *lp;
84	int len, ct;
85	const char *s;
86
87	if ((lp = (line_t *) malloc(sizeof(line_t))) == NULL) {
88		fprintf(stderr, "%s\n", strerror(errno));
89		errmsg = "out of memory";
90		return NULL;
91	}
92	/* assert: cs is '\n' terminated */
93	for (s = cs; *s != '\n'; s++)
94		;
95	if (s - cs >= LINECHARS) {
96		errmsg = "line too long";
97		free(lp);
98		return NULL;
99	}
100	len = s - cs;
101	/* out of position */
102	if (seek_write) {
103		if (fseeko(sfp, (off_t)0, SEEK_END) < 0) {
104			fprintf(stderr, "%s\n", strerror(errno));
105			errmsg = "cannot seek temp file";
106			free(lp);
107			return NULL;
108		}
109		sfseek = ftello(sfp);
110		seek_write = 0;
111	}
112	/* assert: SPL1() */
113	if ((ct = fwrite(cs, sizeof(char), len, sfp)) < 0 || ct != len) {
114		sfseek = -1;
115		fprintf(stderr, "%s\n", strerror(errno));
116		errmsg = "cannot write temp file";
117		free(lp);
118		return NULL;
119	}
120	lp->len = len;
121	lp->seek  = sfseek;
122	add_line_node(lp);
123	sfseek += len;			/* update file position */
124	return ++s;
125}
126
127
128/* add_line_node: add a line node in the editor buffer after the current line */
129void
130add_line_node(line_t *lp)
131{
132	line_t *cp;
133
134	cp = get_addressed_line_node(current_addr);				/* this get_addressed_line_node last! */
135	INSQUE(lp, cp);
136	addr_last++;
137	current_addr++;
138}
139
140
141/* get_line_node_addr: return line number of pointer */
142long
143get_line_node_addr(line_t *lp)
144{
145	line_t *cp = &buffer_head;
146	long n = 0;
147
148	while (cp != lp && (cp = cp->q_forw) != &buffer_head)
149		n++;
150	if (n && cp == &buffer_head) {
151		errmsg = "invalid address";
152		return ERR;
153	 }
154	 return n;
155}
156
157
158/* get_addressed_line_node: return pointer to a line node in the editor buffer */
159line_t *
160get_addressed_line_node(long n)
161{
162	static line_t *lp = &buffer_head;
163	static long on = 0;
164
165	SPL1();
166	if (n > on)
167		if (n <= (on + addr_last) >> 1)
168			for (; on < n; on++)
169				lp = lp->q_forw;
170		else {
171			lp = buffer_head.q_back;
172			for (on = addr_last; on > n; on--)
173				lp = lp->q_back;
174		}
175	else
176		if (n >= on >> 1)
177			for (; on > n; on--)
178				lp = lp->q_back;
179		else {
180			lp = &buffer_head;
181			for (on = 0; on < n; on++)
182				lp = lp->q_forw;
183		}
184	SPL0();
185	return lp;
186}
187
188static char sfn[15] = "";			/* scratch file name */
189
190/* open_sbuf: open scratch file */
191int
192open_sbuf(void)
193{
194	int fd;
195	int u;
196
197	isbinary = newline_added = 0;
198	u = umask(077);
199	strcpy(sfn, "/tmp/ed.XXXXXX");
200	if ((fd = mkstemp(sfn)) == -1 ||
201	    (sfp = fdopen(fd, "w+")) == NULL) {
202		if (fd != -1)
203			close(fd);
204		perror(sfn);
205		errmsg = "cannot open temp file";
206		umask(u);
207		return ERR;
208	}
209	umask(u);
210	return 0;
211}
212
213
214/* close_sbuf: close scratch file */
215int
216close_sbuf(void)
217{
218	if (sfp) {
219		if (fclose(sfp) < 0) {
220			fprintf(stderr, "%s: %s\n", sfn, strerror(errno));
221			errmsg = "cannot close temp file";
222			return ERR;
223		}
224		sfp = NULL;
225		unlink(sfn);
226	}
227	sfseek = seek_write = 0;
228	return 0;
229}
230
231
232/* quit: remove_lines scratch file and exit */
233void
234quit(int n)
235{
236	if (sfp) {
237		fclose(sfp);
238		unlink(sfn);
239	}
240	exit(n);
241}
242
243
244static unsigned char ctab[256];		/* character translation table */
245
246/* init_buffers: open scratch buffer; initialize line queue */
247void
248init_buffers(void)
249{
250	int i = 0;
251
252	/* Read stdin one character at a time to avoid i/o contention
253	   with shell escapes invoked by nonterminal input, e.g.,
254	   ed - <<EOF
255	   !cat
256	   hello, world
257	   EOF */
258	setbuffer(stdin, stdinbuf, 1);
259
260	/* Ensure stdout is line buffered. This avoids bogus delays
261	   of output if stdout is piped through utilities to a terminal. */
262	setvbuf(stdout, NULL, _IOLBF, 0);
263	if (open_sbuf() < 0)
264		quit(2);
265	REQUE(&buffer_head, &buffer_head);
266	for (i = 0; i < 256; i++)
267		ctab[i] = i;
268}
269
270
271/* translit_text: translate characters in a string */
272char *
273translit_text(char *s, int len, int from, int to)
274{
275	static int i = 0;
276
277	unsigned char *us;
278
279	ctab[i] = i;			/* restore table to initial state */
280	ctab[i = from] = to;
281	for (us = (unsigned char *) s; len-- > 0; us++)
282		*us = ctab[*us];
283	return s;
284}
285