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 * @(#)re.c,v 1.6 1994/02/01 00:34:43 alm Exp 29 * $FreeBSD: src/bin/ed/re.c,v 1.20 2003/07/20 10:24:09 ru Exp $ 30 * $DragonFly: src/bin/ed/re.c,v 1.4 2007/04/06 23:36:54 pavalos Exp $ 31 */ 32 33 #include "ed.h" 34 35 36 extern int patlock; 37 38 const char *errmsg = ""; 39 40 /* get_compiled_pattern: return pointer to compiled pattern from command 41 buffer */ 42 pattern_t * 43 get_compiled_pattern(void) 44 { 45 static pattern_t *expr = NULL; 46 static char error[1024]; 47 48 char *exprs; 49 char delimiter; 50 int n; 51 52 if ((delimiter = *ibufp) == ' ') { 53 errmsg = "invalid pattern delimiter"; 54 return NULL; 55 } else if (delimiter == '\n' || *++ibufp == '\n' || *ibufp == delimiter) { 56 if (!expr) 57 errmsg = "no previous pattern"; 58 return expr; 59 } else if ((exprs = extract_pattern(delimiter)) == NULL) 60 return NULL; 61 /* buffer alloc'd && not reserved */ 62 if (expr && !patlock) 63 regfree(expr); 64 else if ((expr = (pattern_t *) malloc(sizeof(pattern_t))) == NULL) { 65 fprintf(stderr, "%s\n", strerror(errno)); 66 errmsg = "out of memory"; 67 return NULL; 68 } 69 patlock = 0; 70 if ((n = regcomp(expr, exprs, 0))) { 71 regerror(n, expr, error, sizeof error); 72 errmsg = error; 73 free(expr); 74 return expr = NULL; 75 } 76 return expr; 77 } 78 79 80 /* extract_pattern: copy a pattern string from the command buffer; return 81 pointer to the copy */ 82 char * 83 extract_pattern(int delimiter) 84 { 85 static char *lhbuf = NULL; /* buffer */ 86 static int lhbufsz = 0; /* buffer size */ 87 88 char *nd; 89 int len; 90 91 for (nd = ibufp; *nd != delimiter && *nd != '\n'; nd++) 92 switch (*nd) { 93 default: 94 break; 95 case '[': 96 if ((nd = parse_char_class(++nd)) == NULL) { 97 errmsg = "unbalanced brackets ([])"; 98 return NULL; 99 } 100 break; 101 case '\\': 102 if (*++nd == '\n') { 103 errmsg = "trailing backslash (\\)"; 104 return NULL; 105 } 106 break; 107 } 108 len = nd - ibufp; 109 REALLOC(lhbuf, lhbufsz, len + 1, NULL); 110 memcpy(lhbuf, ibufp, len); 111 lhbuf[len] = '\0'; 112 ibufp = nd; 113 return (isbinary) ? NUL_TO_NEWLINE(lhbuf, len) : lhbuf; 114 } 115 116 117 /* parse_char_class: expand a POSIX character class */ 118 char * 119 parse_char_class(char *s) 120 { 121 int c, d; 122 123 if (*s == '^') 124 s++; 125 if (*s == ']') 126 s++; 127 for (; *s != ']' && *s != '\n'; s++) 128 if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '=')) 129 for (s++, c = *++s; *s != ']' || c != d; s++) 130 if ((c = *s) == '\n') 131 return NULL; 132 return (*s == ']') ? s : NULL; 133 } 134