1 /* re.c: This file contains the regular expression interface routines for
2 the 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 #include "ed.h"
31
32 const char *errmsg = "";
33
34 /* get_compiled_pattern: return pointer to compiled pattern from command
35 buffer */
36 pattern_t *
get_compiled_pattern(void)37 get_compiled_pattern(void)
38 {
39 static pattern_t *expr = NULL;
40 static char error[1024];
41
42 char *exprs;
43 char delimiter;
44 int n;
45
46 if ((delimiter = *ibufp) == ' ') {
47 errmsg = "invalid pattern delimiter";
48 return NULL;
49 } else if (delimiter == '\n' || *++ibufp == '\n' || *ibufp == delimiter) {
50 if (!expr)
51 errmsg = "no previous pattern";
52 return expr;
53 } else if ((exprs = extract_pattern(delimiter)) == NULL)
54 return NULL;
55 /* buffer alloc'd && not reserved */
56 if (expr && !patlock)
57 regfree(expr);
58 else if ((expr = (pattern_t *) malloc(sizeof(pattern_t))) == NULL) {
59 fprintf(stderr, "%s\n", strerror(errno));
60 errmsg = "out of memory";
61 return NULL;
62 }
63 patlock = 0;
64 if ((n = regcomp(expr, exprs, 0))) {
65 regerror(n, expr, error, sizeof error);
66 errmsg = error;
67 free(expr);
68 return expr = NULL;
69 }
70 return expr;
71 }
72
73
74 /* extract_pattern: copy a pattern string from the command buffer; return
75 pointer to the copy */
76 char *
extract_pattern(int delimiter)77 extract_pattern(int delimiter)
78 {
79 static char *lhbuf = NULL; /* buffer */
80 static int lhbufsz = 0; /* buffer size */
81
82 char *nd;
83 int len;
84
85 for (nd = ibufp; *nd != delimiter && *nd != '\n'; nd++)
86 switch (*nd) {
87 default:
88 break;
89 case '[':
90 if ((nd = parse_char_class(nd + 1)) == NULL) {
91 errmsg = "unbalanced brackets ([])";
92 return NULL;
93 }
94 break;
95 case '\\':
96 if (*++nd == '\n') {
97 errmsg = "trailing backslash (\\)";
98 return NULL;
99 }
100 break;
101 }
102 len = nd - ibufp;
103 REALLOC(lhbuf, lhbufsz, len + 1, NULL);
104 memcpy(lhbuf, ibufp, len);
105 lhbuf[len] = '\0';
106 ibufp = nd;
107 return (isbinary) ? NUL_TO_NEWLINE(lhbuf, len) : lhbuf;
108 }
109
110
111 /* parse_char_class: expand a POSIX character class */
112 char *
parse_char_class(char * s)113 parse_char_class(char *s)
114 {
115 int c, d;
116
117 if (*s == '^')
118 s++;
119 if (*s == ']')
120 s++;
121 for (; *s != ']' && *s != '\n'; s++)
122 if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '='))
123 for (s++, c = *++s; *s != ']' || c != d; s++)
124 if ((c = *s) == '\n')
125 return NULL;
126 return (*s == ']') ? s : NULL;
127 }
128