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