xref: /netbsd-src/bin/ed/buf.c (revision 9573504567626934c7ee01c7dce0c4bb1dfe7403)
1 /*	$NetBSD: buf.c,v 1.15 1995/04/23 10:07:28 cgd Exp $	*/
2 
3 /* buf.c: This file contains the scratch-file buffer rountines for the
4    ed line editor. */
5 /*-
6  * Copyright (c) 1993 Andrew Moore, Talke Studio.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #ifndef lint
32 #if 0
33 static char *rcsid = "@(#)buf.c,v 1.4 1994/02/01 00:34:35 alm Exp";
34 #else
35 static char rcsid[] = "$NetBSD: buf.c,v 1.15 1995/04/23 10:07:28 cgd Exp $";
36 #endif
37 #endif /* not lint */
38 
39 #include <sys/file.h>
40 #include <sys/stat.h>
41 
42 #include "ed.h"
43 
44 
45 FILE *sfp;				/* scratch file pointer */
46 off_t sfseek;				/* scratch file position */
47 int seek_write;				/* seek before writing */
48 line_t buffer_head;			/* incore buffer */
49 
50 /* get_sbuf_line: get a line of text from the scratch file; return pointer
51    to the text */
52 char *
53 get_sbuf_line(lp)
54 	line_t *lp;
55 {
56 	static char *sfbuf = NULL;	/* buffer */
57 	static int sfbufsz = 0;		/* buffer size */
58 
59 	int len, ct;
60 
61 	if (lp == &buffer_head)
62 		return NULL;
63 	seek_write = 1;				/* force seek on write */
64 	/* out of position */
65 	if (sfseek != lp->seek) {
66 		sfseek = lp->seek;
67 		if (fseek(sfp, sfseek, SEEK_SET) < 0) {
68 			fprintf(stderr, "%s\n", strerror(errno));
69 			sprintf(errmsg, "cannot seek temp file");
70 			return NULL;
71 		}
72 	}
73 	len = lp->len;
74 	REALLOC(sfbuf, sfbufsz, len + 1, NULL);
75 	if ((ct = fread(sfbuf, sizeof(char), len, sfp)) <  0 || ct != len) {
76 		fprintf(stderr, "%s\n", strerror(errno));
77 		sprintf(errmsg, "cannot read temp file");
78 		return NULL;
79 	}
80 	sfseek += len;				/* update file position */
81 	sfbuf[len] = '\0';
82 	return sfbuf;
83 }
84 
85 
86 /* put_sbuf_line: write a line of text to the scratch file and add a line node
87    to the editor buffer;  return a pointer to the end of the text */
88 char *
89 put_sbuf_line(cs)
90 	char *cs;
91 {
92 	line_t *lp;
93 	int len, ct;
94 	char *s;
95 
96 	if ((lp = (line_t *) malloc(sizeof(line_t))) == NULL) {
97 		fprintf(stderr, "%s\n", strerror(errno));
98 		sprintf(errmsg, "out of memory");
99 		return NULL;
100 	}
101 	/* assert: cs is '\n' terminated */
102 	for (s = cs; *s != '\n'; s++)
103 		;
104 	if (s - cs >= LINECHARS) {
105 		sprintf(errmsg, "line too long");
106 		return NULL;
107 	}
108 	len = s - cs;
109 	/* out of position */
110 	if (seek_write) {
111 		if (fseek(sfp, 0L, SEEK_END) < 0) {
112 			fprintf(stderr, "%s\n", strerror(errno));
113 			sprintf(errmsg, "cannot seek temp file");
114 			return NULL;
115 		}
116 		sfseek = ftell(sfp);
117 		seek_write = 0;
118 	}
119 	/* assert: SPL1() */
120 	if ((ct = fwrite(cs, sizeof(char), len, sfp)) < 0 || ct != len) {
121 		sfseek = -1;
122 		fprintf(stderr, "%s\n", strerror(errno));
123 		sprintf(errmsg, "cannot write temp file");
124 		return NULL;
125 	}
126 	lp->len = len;
127 	lp->seek  = sfseek;
128 	add_line_node(lp);
129 	sfseek += len;			/* update file position */
130 	return ++s;
131 }
132 
133 
134 /* add_line_node: add a line node in the editor buffer after the current line */
135 void
136 add_line_node(lp)
137 	line_t *lp;
138 {
139 	line_t *cp;
140 
141 	cp = get_addressed_line_node(current_addr);				/* this get_addressed_line_node last! */
142 	INSQUE(lp, cp);
143 	addr_last++;
144 	current_addr++;
145 }
146 
147 
148 /* get_line_node_addr: return line number of pointer */
149 long
150 get_line_node_addr(lp)
151 	line_t *lp;
152 {
153 	line_t *cp = &buffer_head;
154 	long n = 0;
155 
156 	while (cp != lp && (cp = cp->q_forw) != &buffer_head)
157 		n++;
158 	if (n && cp == &buffer_head) {
159 		sprintf(errmsg, "invalid address");
160 		return ERR;
161 	 }
162 	 return n;
163 }
164 
165 
166 /* get_addressed_line_node: return pointer to a line node in the editor buffer */
167 line_t *
168 get_addressed_line_node(n)
169 	long n;
170 {
171 	static line_t *lp = &buffer_head;
172 	static long on = 0;
173 
174 	SPL1();
175 	if (n > on)
176 		if (n <= (on + addr_last) >> 1)
177 			for (; on < n; on++)
178 				lp = lp->q_forw;
179 		else {
180 			lp = buffer_head.q_back;
181 			for (on = addr_last; on > n; on--)
182 				lp = lp->q_back;
183 		}
184 	else
185 		if (n >= on >> 1)
186 			for (; on > n; on--)
187 				lp = lp->q_back;
188 		else {
189 			lp = &buffer_head;
190 			for (on = 0; on < n; on++)
191 				lp = lp->q_forw;
192 		}
193 	SPL0();
194 	return lp;
195 }
196 
197 
198 extern int newline_added;
199 
200 char sfn[15] = "";				/* scratch file name */
201 
202 /* open_sbuf: open scratch file */
203 int
204 open_sbuf()
205 {
206 	int u;
207 
208 	isbinary = newline_added = 0;
209 	u = umask(077);
210 	strcpy(sfn, "/tmp/ed.XXXXXX");
211 	if (mktemp(sfn) == NULL || (sfp = fopen(sfn, "w+")) == NULL) {
212 		fprintf(stderr, "%s: %s\n", sfn, strerror(errno));
213 		sprintf(errmsg, "cannot open temp file");
214 		umask(u);
215 		return ERR;
216 	}
217 	umask(u);
218 	return 0;
219 }
220 
221 
222 /* close_sbuf: close scratch file */
223 int
224 close_sbuf()
225 {
226 	if (sfp) {
227 		if (fclose(sfp) < 0) {
228 			fprintf(stderr, "%s: %s\n", sfn, strerror(errno));
229 			sprintf(errmsg, "cannot close temp file");
230 			return ERR;
231 		}
232 		sfp = NULL;
233 		unlink(sfn);
234 	}
235 	sfseek = seek_write = 0;
236 	return 0;
237 }
238 
239 
240 /* quit: remove_lines scratch file and exit */
241 void
242 quit(n)
243 	int n;
244 {
245 	if (sfp) {
246 		fclose(sfp);
247 		unlink(sfn);
248 	}
249 	exit(n);
250 }
251 
252 
253 unsigned char ctab[256];		/* character translation table */
254 
255 /* init_buffers: open scratch buffer; initialize line queue */
256 void
257 init_buffers()
258 {
259 	int i = 0;
260 
261 	/* Read stdin one character at a time to avoid i/o contention
262 	   with shell escapes invoked by nonterminal input, e.g.,
263 	   ed - <<EOF
264 	   !cat
265 	   hello, world
266 	   EOF */
267 	setbuffer(stdin, stdinbuf, 1);
268 	if (open_sbuf() < 0)
269 		quit(2);
270 	REQUE(&buffer_head, &buffer_head);
271 	for (i = 0; i < 256; i++)
272 		ctab[i] = i;
273 }
274 
275 
276 /* translit_text: translate characters in a string */
277 char *
278 translit_text(s, len, from, to)
279 	char *s;
280 	int len;
281 	int from;
282 	int to;
283 {
284 	static int i = 0;
285 
286 	unsigned char *us;
287 
288 	ctab[i] = i;			/* restore table to initial state */
289 	ctab[i = from] = to;
290 	for (us = (unsigned char *) s; len-- > 0; us++)
291 		*us = ctab[*us];
292 	return s;
293 }
294