1 /* $OpenBSD: regsub.c,v 1.3 1996/12/14 07:01:29 tholo Exp $ */
2
3 /*
4 * regsub
5 *
6 * Copyright (c) 1986 by University of Toronto.
7 * Written by Henry Spencer. Not derived from licensed software.
8 *
9 * Permission is granted to anyone to use this software for any
10 * purpose on any computer system, and to redistribute it freely,
11 * subject to the following restrictions:
12 *
13 * 1. The author is not responsible for the consequences of use of
14 * this software, no matter how awful, even if they arise
15 * from defects in it.
16 *
17 * 2. The origin of this software must not be misrepresented, either
18 * by explicit claim or by omission.
19 *
20 * 3. Altered versions must be plainly marked as such, and must not
21 * be misrepresented as being the original software.
22 */
23
24 #ifndef lint
25 static char *rcsid = "$OpenBSD: regsub.c,v 1.3 1996/12/14 07:01:29 tholo Exp $";
26 #endif /* not lint */
27
28 #include <regexp.h>
29 #include <stdio.h>
30 #include <string.h>
31 #include "regmagic.h"
32
33 #ifndef CHARBITS
34 #define UCHARAT(p) ((int)*(unsigned char *)(p))
35 #else
36 #define UCHARAT(p) ((int)*(p)&CHARBITS)
37 #endif
38
39 /*
40 - regsub - perform substitutions after a regexp match
41 */
42 void
v8_regsub(prog,source,dest)43 v8_regsub(prog, source, dest)
44 const regexp *prog;
45 const char *source;
46 char *dest;
47 {
48 register const char *src;
49 register size_t len;
50 register char *dst;
51 register char c;
52 register int no;
53
54 if (prog == NULL || source == NULL || dest == NULL) {
55 v8_regerror("NULL parm to regsub");
56 return;
57 }
58 if (UCHARAT(prog->program) != MAGIC) {
59 v8_regerror("damaged regexp fed to regsub");
60 return;
61 }
62
63 src = source;
64 dst = dest;
65 while ((c = *src++) != '\0') {
66 if (c == '&')
67 no = 0;
68 else if (c == '\\' && '0' <= *src && *src <= '9')
69 no = *src++ - '0';
70 else
71 no = -1;
72 if (no < 0) { /* Ordinary character. */
73 if (c == '\\' && (*src == '\\' || *src == '&'))
74 c = *src++;
75 *dst++ = c;
76 } else if (prog->startp[no] != NULL && prog->endp[no] != NULL) {
77 len = prog->endp[no] - prog->startp[no];
78 (void) strncpy(dst, prog->startp[no], len);
79 dst += len;
80 if (len != 0 && *(dst-1) == '\0') { /* strncpy hit NUL. */
81 v8_regerror("damaged match string");
82 return;
83 }
84 }
85 }
86 *dst++ = '\0';
87 }
88