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 * 4. 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 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)alias.c 8.3 (Berkeley) 5/4/95"; 36 #endif 37 #endif /* not lint */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <stdlib.h> 42 #include "shell.h" 43 #include "output.h" 44 #include "error.h" 45 #include "memalloc.h" 46 #include "mystring.h" 47 #include "alias.h" 48 #include "options.h" /* XXX for argptr (should remove?) */ 49 #include "builtins.h" 50 51 #define ATABSIZE 39 52 53 static struct alias *atab[ATABSIZE]; 54 static int aliases; 55 56 static void setalias(const char *, const char *); 57 static int unalias(const char *); 58 static struct alias **hashalias(const char *); 59 60 static 61 void 62 setalias(const char *name, const char *val) 63 { 64 struct alias *ap, **app; 65 66 app = hashalias(name); 67 for (ap = *app; ap; ap = ap->next) { 68 if (equal(name, ap->name)) { 69 INTOFF; 70 ckfree(ap->val); 71 /* See HACK below. */ 72 #ifdef notyet 73 ap->val = savestr(val); 74 #else 75 { 76 size_t len = strlen(val); 77 ap->val = ckmalloc(len + 2); 78 memcpy(ap->val, val, len); 79 ap->val[len] = ' '; 80 ap->val[len+1] = '\0'; 81 } 82 #endif 83 INTON; 84 return; 85 } 86 } 87 /* not found */ 88 INTOFF; 89 ap = ckmalloc(sizeof (struct alias)); 90 ap->name = savestr(name); 91 /* 92 * XXX - HACK: in order that the parser will not finish reading the 93 * alias value off the input before processing the next alias, we 94 * dummy up an extra space at the end of the alias. This is a crock 95 * and should be re-thought. The idea (if you feel inclined to help) 96 * is to avoid alias recursions. The mechanism used is: when 97 * expanding an alias, the value of the alias is pushed back on the 98 * input as a string and a pointer to the alias is stored with the 99 * string. The alias is marked as being in use. When the input 100 * routine finishes reading the string, it marks the alias not 101 * in use. The problem is synchronization with the parser. Since 102 * it reads ahead, the alias is marked not in use before the 103 * resulting token(s) is next checked for further alias sub. The 104 * H A C K is that we add a little fluff after the alias value 105 * so that the string will not be exhausted. This is a good 106 * idea ------- ***NOT*** 107 */ 108 #ifdef notyet 109 ap->val = savestr(val); 110 #else /* hack */ 111 { 112 size_t len = strlen(val); 113 ap->val = ckmalloc(len + 2); 114 memcpy(ap->val, val, len); 115 ap->val[len] = ' '; /* fluff */ 116 ap->val[len+1] = '\0'; 117 } 118 #endif 119 ap->flag = 0; 120 ap->next = *app; 121 *app = ap; 122 aliases++; 123 INTON; 124 } 125 126 static int 127 unalias(const char *name) 128 { 129 struct alias *ap, **app; 130 131 app = hashalias(name); 132 133 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 134 if (equal(name, ap->name)) { 135 /* 136 * if the alias is currently in use (i.e. its 137 * buffer is being used by the input routine) we 138 * just null out the name instead of freeing it. 139 * We could clear it out later, but this situation 140 * is so rare that it hardly seems worth it. 141 */ 142 if (ap->flag & ALIASINUSE) 143 *ap->name = '\0'; 144 else { 145 INTOFF; 146 *app = ap->next; 147 ckfree(ap->name); 148 ckfree(ap->val); 149 ckfree(ap); 150 INTON; 151 } 152 aliases--; 153 return (0); 154 } 155 } 156 157 return (1); 158 } 159 160 static void 161 rmaliases(void) 162 { 163 struct alias *ap, *tmp; 164 int i; 165 166 INTOFF; 167 for (i = 0; i < ATABSIZE; i++) { 168 ap = atab[i]; 169 atab[i] = NULL; 170 while (ap) { 171 ckfree(ap->name); 172 ckfree(ap->val); 173 tmp = ap; 174 ap = ap->next; 175 ckfree(tmp); 176 } 177 } 178 aliases = 0; 179 INTON; 180 } 181 182 struct alias * 183 lookupalias(const char *name, int check) 184 { 185 struct alias *ap = *hashalias(name); 186 187 for (; ap; ap = ap->next) { 188 if (equal(name, ap->name)) { 189 if (check && (ap->flag & ALIASINUSE)) 190 return (NULL); 191 return (ap); 192 } 193 } 194 195 return (NULL); 196 } 197 198 static int 199 comparealiases(const void *p1, const void *p2) 200 { 201 const struct alias *const *a1 = p1; 202 const struct alias *const *a2 = p2; 203 204 return strcmp((*a1)->name, (*a2)->name); 205 } 206 207 static void 208 printalias(const struct alias *a) 209 { 210 char *p; 211 212 out1fmt("%s=", a->name); 213 /* Don't print the space added above. */ 214 p = a->val + strlen(a->val) - 1; 215 *p = '\0'; 216 out1qstr(a->val); 217 *p = ' '; 218 out1c('\n'); 219 } 220 221 static void 222 printaliases(void) 223 { 224 int i, j; 225 struct alias **sorted, *ap; 226 227 sorted = ckmalloc(aliases * sizeof(*sorted)); 228 j = 0; 229 for (i = 0; i < ATABSIZE; i++) 230 for (ap = atab[i]; ap; ap = ap->next) 231 if (*ap->name != '\0') 232 sorted[j++] = ap; 233 qsort(sorted, aliases, sizeof(*sorted), comparealiases); 234 for (i = 0; i < aliases; i++) 235 printalias(sorted[i]); 236 ckfree(sorted); 237 } 238 239 int 240 aliascmd(int argc, char **argv) 241 { 242 char *n, *v; 243 int ret = 0; 244 struct alias *ap; 245 246 if (argc == 1) { 247 printaliases(); 248 return (0); 249 } 250 while ((n = *++argv) != NULL) { 251 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */ 252 if ((ap = lookupalias(n, 0)) == NULL) { 253 warning("%s: not found", n); 254 ret = 1; 255 } else 256 printalias(ap); 257 else { 258 *v++ = '\0'; 259 setalias(n, v); 260 } 261 } 262 263 return (ret); 264 } 265 266 int 267 unaliascmd(int argc __unused, char **argv __unused) 268 { 269 int i; 270 271 while ((i = nextopt("a")) != '\0') { 272 if (i == 'a') { 273 rmaliases(); 274 return (0); 275 } 276 } 277 for (i = 0; *argptr; argptr++) 278 i |= unalias(*argptr); 279 280 return (i); 281 } 282 283 static struct alias ** 284 hashalias(const char *p) 285 { 286 unsigned int hashval; 287 288 hashval = *p << 4; 289 while (*p) 290 hashval+= *p++; 291 return &atab[hashval % ATABSIZE]; 292 } 293