1 /* $NetBSD: alias.c,v 1.13 2010/10/29 17:04:48 stacktic 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 1.13 2010/10/29 17:04:48 stacktic 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 ap->flag = 0; 84 /* 85 * XXX - HACK: in order that the parser will not finish reading the 86 * alias value off the input before processing the next alias, we 87 * dummy up an extra space at the end of the alias. This is a crock 88 * and should be re-thought. The idea (if you feel inclined to help) 89 * is to avoid alias recursions. The mechanism used is: when 90 * expanding an alias, the value of the alias is pushed back on the 91 * input as a string and a pointer to the alias is stored with the 92 * string. The alias is marked as being in use. When the input 93 * routine finishes reading the string, it markes the alias not 94 * in use. The problem is synchronization with the parser. Since 95 * it reads ahead, the alias is marked not in use before the 96 * resulting token(s) is next checked for further alias sub. The 97 * H A C K is that we add a little fluff after the alias value 98 * so that the string will not be exhausted. This is a good 99 * idea ------- ***NOT*** 100 */ 101 #ifdef notyet 102 ap->val = savestr(val); 103 #else /* hack */ 104 { 105 int len = strlen(val); 106 ap->val = ckmalloc(len + 2); 107 memcpy(ap->val, val, len); 108 ap->val[len] = ' '; /* fluff */ 109 ap->val[len+1] = '\0'; 110 } 111 #endif 112 ap->next = *app; 113 *app = ap; 114 INTON; 115 } 116 117 STATIC int 118 unalias(char *name) 119 { 120 struct alias *ap, **app; 121 122 app = hashalias(name); 123 124 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 125 if (equal(name, ap->name)) { 126 /* 127 * if the alias is currently in use (i.e. its 128 * buffer is being used by the input routine) we 129 * just null out the name instead of freeing it. 130 * We could clear it out later, but this situation 131 * is so rare that it hardly seems worth it. 132 */ 133 if (ap->flag & ALIASINUSE) 134 *ap->name = '\0'; 135 else { 136 INTOFF; 137 *app = ap->next; 138 ckfree(ap->name); 139 ckfree(ap->val); 140 ckfree(ap); 141 INTON; 142 } 143 return (0); 144 } 145 } 146 147 return (1); 148 } 149 150 #ifdef mkinit 151 MKINIT void rmaliases(void); 152 153 SHELLPROC { 154 rmaliases(); 155 } 156 #endif 157 158 void 159 rmaliases(void) 160 { 161 struct alias *ap, *tmp; 162 int i; 163 164 INTOFF; 165 for (i = 0; i < ATABSIZE; i++) { 166 ap = atab[i]; 167 atab[i] = NULL; 168 while (ap) { 169 ckfree(ap->name); 170 ckfree(ap->val); 171 tmp = ap; 172 ap = ap->next; 173 ckfree(tmp); 174 } 175 } 176 INTON; 177 } 178 179 struct alias * 180 lookupalias(char *name, int check) 181 { 182 struct alias *ap = *hashalias(name); 183 184 for (; ap; ap = ap->next) { 185 if (equal(name, ap->name)) { 186 if (check && (ap->flag & ALIASINUSE)) 187 return (NULL); 188 return (ap); 189 } 190 } 191 192 return (NULL); 193 } 194 195 char * 196 get_alias_text(char *name) 197 { 198 struct alias *ap; 199 200 ap = lookupalias(name, 0); 201 if (ap == NULL) 202 return NULL; 203 return ap->val; 204 } 205 206 /* 207 * TODO - sort output 208 */ 209 int 210 aliascmd(int argc, char **argv) 211 { 212 char *n, *v; 213 int ret = 0; 214 struct alias *ap; 215 216 if (argc == 1) { 217 int i; 218 219 for (i = 0; i < ATABSIZE; i++) 220 for (ap = atab[i]; ap; ap = ap->next) { 221 if (*ap->name != '\0') { 222 out1fmt("alias %s=", ap->name); 223 print_quoted(ap->val); 224 out1c('\n'); 225 } 226 } 227 return (0); 228 } 229 while ((n = *++argv) != NULL) { 230 if ((v = strchr(n+1, '=')) == NULL) { /* n+1: funny ksh stuff */ 231 if ((ap = lookupalias(n, 0)) == NULL) { 232 outfmt(out2, "alias: %s not found\n", n); 233 ret = 1; 234 } else { 235 out1fmt("alias %s=", n); 236 print_quoted(ap->val); 237 out1c('\n'); 238 } 239 } else { 240 *v++ = '\0'; 241 setalias(n, v); 242 } 243 } 244 245 return (ret); 246 } 247 248 int 249 unaliascmd(int argc, char **argv) 250 { 251 int i; 252 253 while ((i = nextopt("a")) != '\0') { 254 if (i == 'a') { 255 rmaliases(); 256 return (0); 257 } 258 } 259 for (i = 0; *argptr; argptr++) 260 i = unalias(*argptr); 261 262 return (i); 263 } 264 265 STATIC struct alias ** 266 hashalias(char *p) 267 { 268 unsigned int hashval; 269 270 hashval = *p << 4; 271 while (*p) 272 hashval+= *p++; 273 return &atab[hashval % ATABSIZE]; 274 } 275