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 #ifndef lint 30 #if 0 31 static char * const rcsid = "@(#)re.c,v 1.6 1994/02/01 00:34:43 alm Exp"; 32 #else 33 static char * const rcsid = 34 "$FreeBSD$"; 35 #endif 36 #endif /* not lint */ 37 38 #include "ed.h" 39 40 41 extern int patlock; 42 43 char errmsg[MAXPATHLEN + 40] = ""; 44 45 /* get_compiled_pattern: return pointer to compiled pattern from command 46 buffer */ 47 pattern_t * 48 get_compiled_pattern() 49 { 50 static pattern_t *exp = NULL; 51 52 char *exps; 53 char delimiter; 54 int n; 55 56 if ((delimiter = *ibufp) == ' ') { 57 sprintf(errmsg, "invalid pattern delimiter"); 58 return NULL; 59 } else if (delimiter == '\n' || *++ibufp == '\n' || *ibufp == delimiter) { 60 if (!exp) sprintf(errmsg, "no previous pattern"); 61 return exp; 62 } else if ((exps = extract_pattern(delimiter)) == NULL) 63 return NULL; 64 /* buffer alloc'd && not reserved */ 65 if (exp && !patlock) 66 regfree(exp); 67 else if ((exp = (pattern_t *) malloc(sizeof(pattern_t))) == NULL) { 68 fprintf(stderr, "%s\n", strerror(errno)); 69 sprintf(errmsg, "out of memory"); 70 return NULL; 71 } 72 patlock = 0; 73 if ((n = regcomp(exp, exps, 0))) { 74 regerror(n, exp, errmsg, sizeof errmsg); 75 free(exp); 76 return exp = NULL; 77 } 78 return exp; 79 } 80 81 82 /* extract_pattern: copy a pattern string from the command buffer; return 83 pointer to the copy */ 84 char * 85 extract_pattern(delimiter) 86 int delimiter; 87 { 88 static char *lhbuf = NULL; /* buffer */ 89 static int lhbufsz = 0; /* buffer size */ 90 91 char *nd; 92 int len; 93 94 for (nd = ibufp; *nd != delimiter && *nd != '\n'; nd++) 95 switch (*nd) { 96 default: 97 break; 98 case '[': 99 if ((nd = parse_char_class(++nd)) == NULL) { 100 sprintf(errmsg, "unbalanced brackets ([])"); 101 return NULL; 102 } 103 break; 104 case '\\': 105 if (*++nd == '\n') { 106 sprintf(errmsg, "trailing backslash (\\)"); 107 return NULL; 108 } 109 break; 110 } 111 len = nd - ibufp; 112 REALLOC(lhbuf, lhbufsz, len + 1, NULL); 113 memcpy(lhbuf, ibufp, len); 114 lhbuf[len] = '\0'; 115 ibufp = nd; 116 return (isbinary) ? NUL_TO_NEWLINE(lhbuf, len) : lhbuf; 117 } 118 119 120 /* parse_char_class: expand a POSIX character class */ 121 char * 122 parse_char_class(s) 123 char *s; 124 { 125 int c, d; 126 127 if (*s == '^') 128 s++; 129 if (*s == ']') 130 s++; 131 for (; *s != ']' && *s != '\n'; s++) 132 if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '=')) 133 for (s++, c = *++s; *s != ']' || c != d; s++) 134 if ((c = *s) == '\n') 135 return NULL; 136 return (*s == ']') ? s : NULL; 137 } 138