xref: /openbsd/usr.bin/vi/common/util.c (revision df930be7)
1 /*-
2  * Copyright (c) 1991, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 static char sccsid[] = "@(#)util.c	8.74 (Berkeley) 8/17/94";
36 #endif /* not lint */
37 
38 #include <sys/types.h>
39 #include <sys/queue.h>
40 #include <sys/time.h>
41 
42 #include <bitstring.h>
43 #include <limits.h>
44 #include <signal.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <termios.h>
49 #include <unistd.h>
50 
51 #include "compat.h"
52 #include <curses.h>
53 #include <db.h>
54 #include <regex.h>
55 
56 #include "vi.h"
57 
58 /*
59  * binc --
60  *	Increase the size of a buffer.
61  */
62 void *
63 binc(sp, bp, bsizep, min)
64 	SCR *sp;			/* sp MAY BE NULL!!! */
65 	void *bp;
66 	size_t *bsizep, min;
67 {
68 	size_t csize;
69 
70 	/* If already larger than the minimum, just return. */
71 	if (min && *bsizep >= min)
72 		return (bp);
73 
74 	csize = *bsizep + MAX(min, 256);
75 	REALLOC(sp, bp, void *, csize);
76 
77 	if (bp == NULL) {
78 		/*
79 		 * Theoretically, realloc is supposed to leave any already
80 		 * held memory alone if it can't get more.  Don't trust it.
81 		 */
82 		*bsizep = 0;
83 		return (NULL);
84 	}
85 	/*
86 	 * Memory is guaranteed to be zero-filled, various parts of
87 	 * nvi depend on this.
88 	 */
89 	memset((char *)bp + *bsizep, 0, csize - *bsizep);
90 	*bsizep = csize;
91 	return (bp);
92 }
93 
94 /*
95  * nonblank --
96  *	Set the column number of the first non-blank character
97  *	including or after the starting column.  On error, set
98  *	the column to 0, it's safest.
99  */
100 int
101 nonblank(sp, ep, lno, cnop)
102 	SCR *sp;
103 	EXF *ep;
104 	recno_t lno;
105 	size_t *cnop;
106 {
107 	char *p;
108 	size_t cnt, len, off;
109 
110 	/* Default. */
111 	off = *cnop;
112 	*cnop = 0;
113 
114 	/* Get the line. */
115 	if ((p = file_gline(sp, ep, lno, &len)) == NULL) {
116 		if (file_lline(sp, ep, &lno))
117 			return (1);
118 		if (lno == 0)
119 			return (0);
120 		GETLINE_ERR(sp, lno);
121 		return (1);
122 	}
123 
124 	/* Set the offset. */
125 	if (len == 0 || off >= len)
126 		return (0);
127 
128 	for (cnt = off, p = &p[off],
129 	    len -= off; len && isblank(*p); ++cnt, ++p, --len);
130 
131 	/* Set the return. */
132 	*cnop = len ? cnt : cnt - 1;
133 	return (0);
134 }
135 
136 /*
137  * tail --
138  *	Return tail of a path.
139  */
140 char *
141 tail(path)
142 	char *path;
143 {
144 	char *p;
145 
146 	if ((p = strrchr(path, '/')) == NULL)
147 		return (path);
148 	return (p + 1);
149 }
150 
151 /*
152  * set_alt_name --
153  *	Set the alternate file name.
154  *
155  * Swap the alternate file name.  It's a routine because I wanted some place
156  * to hang this comment.  The alternate file name (normally referenced using
157  * the special character '#' during file expansion) is set by many
158  * operations.  In the historic vi, the commands "ex", and "edit" obviously
159  * set the alternate file name because they switched the underlying file.
160  * Less obviously, the "read", "file", "write" and "wq" commands set it as
161  * well.  In this implementation, some new commands have been added to the
162  * list.  Where it gets interesting is that the alternate file name is set
163  * multiple times by some commands.  If an edit attempt fails (for whatever
164  * reason, like the current file is modified but as yet unwritten), it is
165  * set to the file name that the user was unable to edit.  If the edit
166  * succeeds, it is set to the last file name that was edited.  Good fun.
167  *
168  * If the user edits a temporary file, there are time when there isn't an
169  * alternative file name.  A name argument of NULL turns it off.
170  */
171 void
172 set_alt_name(sp, name)
173 	SCR *sp;
174 	char *name;
175 {
176 	if (sp->alt_name != NULL)
177 		free(sp->alt_name);
178 	if (name == NULL)
179 		sp->alt_name = NULL;
180 	else if ((sp->alt_name = strdup(name)) == NULL)
181 		msgq(sp, M_SYSERR, NULL);
182 }
183 
184 /*
185  * v_strdup --
186  *	Strdup for wide character strings with an associated length.
187  */
188 CHAR_T *
189 v_strdup(sp, str, len)
190 	SCR *sp;
191 	CHAR_T *str;
192 	size_t len;
193 {
194 	CHAR_T *copy;
195 
196 	MALLOC(sp, copy, CHAR_T *, len + 1);
197 	if (copy == NULL)
198 		return (NULL);
199 	memmove(copy, str, len * sizeof(CHAR_T));
200 	copy[len] = '\0';
201 	return (copy);
202 }
203 
204 /*
205  * vi_putchar --
206  *	Functional version of putchar, for tputs.
207  */
208 void
209 vi_putchar(ch)
210 	int ch;
211 {
212 	(void)putchar(ch);
213 }
214