1 /* $NetBSD: alias.c,v 1.12 2003/08/07 09:05:29 agc Exp $ */ 2 3 /*- 4 * Copyright (c) 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Kenneth Almquist. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #ifndef lint 37 #if 0 38 static char sccsid[] = "@(#)alias.c 8.3 (Berkeley) 5/4/95"; 39 #else 40 __RCSID("$NetBSD: alias.c,v 1.12 2003/08/07 09:05:29 agc Exp $"); 41 #endif 42 #endif /* not lint */ 43 44 #include <stdlib.h> 45 #include "shell.h" 46 #include "input.h" 47 #include "output.h" 48 #include "error.h" 49 #include "memalloc.h" 50 #include "mystring.h" 51 #include "alias.h" 52 #include "options.h" /* XXX for argptr (should remove?) */ 53 #include "var.h" 54 55 #define ATABSIZE 39 56 57 struct alias *atab[ATABSIZE]; 58 59 STATIC void setalias(char *, char *); 60 STATIC int unalias(char *); 61 STATIC struct alias **hashalias(char *); 62 63 STATIC 64 void 65 setalias(char *name, char *val) 66 { 67 struct alias *ap, **app; 68 69 app = hashalias(name); 70 for (ap = *app; ap; ap = ap->next) { 71 if (equal(name, ap->name)) { 72 INTOFF; 73 ckfree(ap->val); 74 ap->val = savestr(val); 75 INTON; 76 return; 77 } 78 } 79 /* not found */ 80 INTOFF; 81 ap = ckmalloc(sizeof (struct alias)); 82 ap->name = savestr(name); 83 /* 84 * XXX - HACK: in order that the parser will not finish reading the 85 * alias value off the input before processing the next alias, we 86 * dummy up an extra space at the end of the alias. This is a crock 87 * and should be re-thought. The idea (if you feel inclined to help) 88 * is to avoid alias recursions. The mechanism used is: when 89 * expanding an alias, the value of the alias is pushed back on the 90 * input as a string and a pointer to the alias is stored with the 91 * string. The alias is marked as being in use. When the input 92 * routine finishes reading the string, it markes the alias not 93 * in use. The problem is synchronization with the parser. Since 94 * it reads ahead, the alias is marked not in use before the 95 * resulting token(s) is next checked for further alias sub. The 96 * H A C K is that we add a little fluff after the alias value 97 * so that the string will not be exhausted. This is a good 98 * idea ------- ***NOT*** 99 */ 100 #ifdef notyet 101 ap->val = savestr(val); 102 #else /* hack */ 103 { 104 int len = strlen(val); 105 ap->val = ckmalloc(len + 2); 106 memcpy(ap->val, val, len); 107 ap->val[len] = ' '; /* fluff */ 108 ap->val[len+1] = '\0'; 109 } 110 #endif 111 ap->next = *app; 112 *app = ap; 113 INTON; 114 } 115 116 STATIC int 117 unalias(char *name) 118 { 119 struct alias *ap, **app; 120 121 app = hashalias(name); 122 123 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 124 if (equal(name, ap->name)) { 125 /* 126 * if the alias is currently in use (i.e. its 127 * buffer is being used by the input routine) we 128 * just null out the name instead of freeing it. 129 * We could clear it out later, but this situation 130 * is so rare that it hardly seems worth it. 131 */ 132 if (ap->flag & ALIASINUSE) 133 *ap->name = '\0'; 134 else { 135 INTOFF; 136 *app = ap->next; 137 ckfree(ap->name); 138 ckfree(ap->val); 139 ckfree(ap); 140 INTON; 141 } 142 return (0); 143 } 144 } 145 146 return (1); 147 } 148 149 #ifdef mkinit 150 MKINIT void rmaliases(void); 151 152 SHELLPROC { 153 rmaliases(); 154 } 155 #endif 156 157 void 158 rmaliases(void) 159 { 160 struct alias *ap, *tmp; 161 int i; 162 163 INTOFF; 164 for (i = 0; i < ATABSIZE; i++) { 165 ap = atab[i]; 166 atab[i] = NULL; 167 while (ap) { 168 ckfree(ap->name); 169 ckfree(ap->val); 170 tmp = ap; 171 ap = ap->next; 172 ckfree(tmp); 173 } 174 } 175 INTON; 176 } 177 178 struct alias * 179 lookupalias(char *name, int check) 180 { 181 struct alias *ap = *hashalias(name); 182 183 for (; ap; ap = ap->next) { 184 if (equal(name, ap->name)) { 185 if (check && (ap->flag & ALIASINUSE)) 186 return (NULL); 187 return (ap); 188 } 189 } 190 191 return (NULL); 192 } 193 194 char * 195 get_alias_text(char *name) 196 { 197 struct alias *ap; 198 199 ap = lookupalias(name, 0); 200 if (ap == NULL) 201 return NULL; 202 return ap->val; 203 } 204 205 /* 206 * TODO - sort output 207 */ 208 int 209 aliascmd(int argc, char **argv) 210 { 211 char *n, *v; 212 int ret = 0; 213 struct alias *ap; 214 215 if (argc == 1) { 216 int i; 217 218 for (i = 0; i < ATABSIZE; i++) 219 for (ap = atab[i]; ap; ap = ap->next) { 220 if (*ap->name != '\0') { 221 out1fmt("alias %s=", ap->name); 222 print_quoted(ap->val); 223 out1c('\n'); 224 } 225 } 226 return (0); 227 } 228 while ((n = *++argv) != NULL) { 229 if ((v = strchr(n+1, '=')) == NULL) { /* n+1: funny ksh stuff */ 230 if ((ap = lookupalias(n, 0)) == NULL) { 231 outfmt(out2, "alias: %s not found\n", n); 232 ret = 1; 233 } else { 234 out1fmt("alias %s=", n); 235 print_quoted(ap->val); 236 out1c('\n'); 237 } 238 } else { 239 *v++ = '\0'; 240 setalias(n, v); 241 } 242 } 243 244 return (ret); 245 } 246 247 int 248 unaliascmd(int argc, char **argv) 249 { 250 int i; 251 252 while ((i = nextopt("a")) != '\0') { 253 if (i == 'a') { 254 rmaliases(); 255 return (0); 256 } 257 } 258 for (i = 0; *argptr; argptr++) 259 i = unalias(*argptr); 260 261 return (i); 262 } 263 264 STATIC struct alias ** 265 hashalias(char *p) 266 { 267 unsigned int hashval; 268 269 hashval = *p << 4; 270 while (*p) 271 hashval+= *p++; 272 return &atab[hashval % ATABSIZE]; 273 } 274
