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 * 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 * 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 * 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