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