1 /*- 2 * Copyright (c) 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)alias.c 8.3 (Berkeley) 5/4/95 33 * $FreeBSD: head/bin/sh/alias.c 242766 2012-11-08 13:33:48Z jilles $ 34 */ 35 36 #include <stdlib.h> 37 #include "shell.h" 38 #include "output.h" 39 #include "error.h" 40 #include "memalloc.h" 41 #include "mystring.h" 42 #include "alias.h" 43 #include "options.h" /* XXX for argptr (should remove?) */ 44 #include "builtins.h" 45 46 #define ATABSIZE 39 47 48 static struct alias *atab[ATABSIZE]; 49 static int aliases; 50 51 static void setalias(const char *, const char *); 52 static int unalias(const char *); 53 static struct alias **hashalias(const char *); 54 55 static 56 void 57 setalias(const char *name, const char *val) 58 { 59 struct alias *ap, **app; 60 61 app = hashalias(name); 62 for (ap = *app; ap; ap = ap->next) { 63 if (equal(name, ap->name)) { 64 INTOFF; 65 ckfree(ap->val); 66 /* See HACK below. */ 67 #ifdef notyet 68 ap->val = savestr(val); 69 #else 70 { 71 size_t len = strlen(val); 72 ap->val = ckmalloc(len + 2); 73 memcpy(ap->val, val, len); 74 ap->val[len] = ' '; 75 ap->val[len+1] = '\0'; 76 } 77 #endif 78 INTON; 79 return; 80 } 81 } 82 /* not found */ 83 INTOFF; 84 ap = ckmalloc(sizeof (struct alias)); 85 ap->name = savestr(name); 86 /* 87 * XXX - HACK: in order that the parser will not finish reading the 88 * alias value off the input before processing the next alias, we 89 * dummy up an extra space at the end of the alias. This is a crock 90 * and should be re-thought. The idea (if you feel inclined to help) 91 * is to avoid alias recursions. The mechanism used is: when 92 * expanding an alias, the value of the alias is pushed back on the 93 * input as a string and a pointer to the alias is stored with the 94 * string. The alias is marked as being in use. When the input 95 * routine finishes reading the string, it marks the alias not 96 * in use. The problem is synchronization with the parser. Since 97 * it reads ahead, the alias is marked not in use before the 98 * resulting token(s) is next checked for further alias sub. The 99 * H A C K is that we add a little fluff after the alias value 100 * so that the string will not be exhausted. This is a good 101 * idea ------- ***NOT*** 102 */ 103 #ifdef notyet 104 ap->val = savestr(val); 105 #else /* hack */ 106 { 107 size_t len = strlen(val); 108 ap->val = ckmalloc(len + 2); 109 memcpy(ap->val, val, len); 110 ap->val[len] = ' '; /* fluff */ 111 ap->val[len+1] = '\0'; 112 } 113 #endif 114 ap->flag = 0; 115 ap->next = *app; 116 *app = ap; 117 aliases++; 118 INTON; 119 } 120 121 static int 122 unalias(const char *name) 123 { 124 struct alias *ap, **app; 125 126 app = hashalias(name); 127 128 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 129 if (equal(name, ap->name)) { 130 /* 131 * if the alias is currently in use (i.e. its 132 * buffer is being used by the input routine) we 133 * just null out the name instead of freeing it. 134 * We could clear it out later, but this situation 135 * is so rare that it hardly seems worth it. 136 */ 137 if (ap->flag & ALIASINUSE) 138 *ap->name = '\0'; 139 else { 140 INTOFF; 141 *app = ap->next; 142 ckfree(ap->name); 143 ckfree(ap->val); 144 ckfree(ap); 145 INTON; 146 } 147 aliases--; 148 return (0); 149 } 150 } 151 152 return (1); 153 } 154 155 static void 156 rmaliases(void) 157 { 158 struct alias *ap, *tmp; 159 int i; 160 161 INTOFF; 162 for (i = 0; i < ATABSIZE; i++) { 163 ap = atab[i]; 164 atab[i] = NULL; 165 while (ap) { 166 ckfree(ap->name); 167 ckfree(ap->val); 168 tmp = ap; 169 ap = ap->next; 170 ckfree(tmp); 171 } 172 } 173 aliases = 0; 174 INTON; 175 } 176 177 struct alias * 178 lookupalias(const char *name, int check) 179 { 180 struct alias *ap = *hashalias(name); 181 182 for (; ap; ap = ap->next) { 183 if (equal(name, ap->name)) { 184 if (check && (ap->flag & ALIASINUSE)) 185 return (NULL); 186 return (ap); 187 } 188 } 189 190 return (NULL); 191 } 192 193 static int 194 comparealiases(const void *p1, const void *p2) 195 { 196 const struct alias *const *a1 = p1; 197 const struct alias *const *a2 = p2; 198 199 return strcmp((*a1)->name, (*a2)->name); 200 } 201 202 static void 203 printalias(const struct alias *a) 204 { 205 char *p; 206 207 out1fmt("%s=", a->name); 208 /* Don't print the space added above. */ 209 p = a->val + strlen(a->val) - 1; 210 *p = '\0'; 211 out1qstr(a->val); 212 *p = ' '; 213 out1c('\n'); 214 } 215 216 static void 217 printaliases(void) 218 { 219 int i, j; 220 struct alias **sorted, *ap; 221 222 sorted = ckmalloc(aliases * sizeof(*sorted)); 223 j = 0; 224 for (i = 0; i < ATABSIZE; i++) 225 for (ap = atab[i]; ap; ap = ap->next) 226 if (*ap->name != '\0') 227 sorted[j++] = ap; 228 qsort(sorted, aliases, sizeof(*sorted), comparealiases); 229 for (i = 0; i < aliases; i++) 230 printalias(sorted[i]); 231 ckfree(sorted); 232 } 233 234 int 235 aliascmd(int argc, char **argv) 236 { 237 char *n, *v; 238 int ret = 0; 239 struct alias *ap; 240 241 if (argc == 1) { 242 printaliases(); 243 return (0); 244 } 245 while ((n = *++argv) != NULL) { 246 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */ 247 if ((ap = lookupalias(n, 0)) == NULL) { 248 warning("%s: not found", n); 249 ret = 1; 250 } else 251 printalias(ap); 252 else { 253 *v++ = '\0'; 254 setalias(n, v); 255 } 256 } 257 258 return (ret); 259 } 260 261 int 262 unaliascmd(int argc __unused, char **argv __unused) 263 { 264 int i; 265 266 while ((i = nextopt("a")) != '\0') { 267 if (i == 'a') { 268 rmaliases(); 269 return (0); 270 } 271 } 272 for (i = 0; *argptr; argptr++) 273 i |= unalias(*argptr); 274 275 return (i); 276 } 277 278 static struct alias ** 279 hashalias(const char *p) 280 { 281 unsigned int hashval; 282 283 hashval = *p << 4; 284 while (*p) 285 hashval+= *p++; 286 return &atab[hashval % ATABSIZE]; 287 } 288