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 50 #define ATABSIZE 39 51 52 STATIC struct alias *atab[ATABSIZE]; 53 STATIC int aliases; 54 55 STATIC void setalias(const char *, const char *); 56 STATIC int unalias(const char *); 57 STATIC struct alias **hashalias(const char *); 58 59 STATIC 60 void 61 setalias(const char *name, const char *val) 62 { 63 struct alias *ap, **app; 64 65 app = hashalias(name); 66 for (ap = *app; ap; ap = ap->next) { 67 if (equal(name, ap->name)) { 68 INTOFF; 69 ckfree(ap->val); 70 ap->val = savestr(val); 71 INTON; 72 return; 73 } 74 } 75 /* not found */ 76 INTOFF; 77 ap = ckmalloc(sizeof (struct alias)); 78 ap->name = savestr(name); 79 /* 80 * XXX - HACK: in order that the parser will not finish reading the 81 * alias value off the input before processing the next alias, we 82 * dummy up an extra space at the end of the alias. This is a crock 83 * and should be re-thought. The idea (if you feel inclined to help) 84 * is to avoid alias recursions. The mechanism used is: when 85 * expanding an alias, the value of the alias is pushed back on the 86 * input as a string and a pointer to the alias is stored with the 87 * string. The alias is marked as being in use. When the input 88 * routine finishes reading the string, it marks the alias not 89 * in use. The problem is synchronization with the parser. Since 90 * it reads ahead, the alias is marked not in use before the 91 * resulting token(s) is next checked for further alias sub. The 92 * H A C K is that we add a little fluff after the alias value 93 * so that the string will not be exhausted. This is a good 94 * idea ------- ***NOT*** 95 */ 96 #ifdef notyet 97 ap->val = savestr(val); 98 #else /* hack */ 99 { 100 size_t len = strlen(val); 101 ap->val = ckmalloc(len + 2); 102 memcpy(ap->val, val, len); 103 ap->val[len] = ' '; /* fluff */ 104 ap->val[len+1] = '\0'; 105 } 106 #endif 107 ap->flag = 0; 108 ap->next = *app; 109 *app = ap; 110 aliases++; 111 INTON; 112 } 113 114 STATIC int 115 unalias(const char *name) 116 { 117 struct alias *ap, **app; 118 119 app = hashalias(name); 120 121 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 122 if (equal(name, ap->name)) { 123 /* 124 * if the alias is currently in use (i.e. its 125 * buffer is being used by the input routine) we 126 * just null out the name instead of freeing it. 127 * We could clear it out later, but this situation 128 * is so rare that it hardly seems worth it. 129 */ 130 if (ap->flag & ALIASINUSE) 131 *ap->name = '\0'; 132 else { 133 INTOFF; 134 *app = ap->next; 135 ckfree(ap->name); 136 ckfree(ap->val); 137 ckfree(ap); 138 INTON; 139 } 140 aliases--; 141 return (0); 142 } 143 } 144 145 return (1); 146 } 147 148 #ifdef mkinit 149 MKINIT void rmaliases(void); 150 151 SHELLPROC { 152 rmaliases(); 153 } 154 #endif 155 156 void 157 rmaliases(void) 158 { 159 struct alias *ap, *tmp; 160 int i; 161 162 INTOFF; 163 for (i = 0; i < ATABSIZE; i++) { 164 ap = atab[i]; 165 atab[i] = NULL; 166 while (ap) { 167 ckfree(ap->name); 168 ckfree(ap->val); 169 tmp = ap; 170 ap = ap->next; 171 ckfree(tmp); 172 } 173 } 174 aliases = 0; 175 INTON; 176 } 177 178 struct alias * 179 lookupalias(const 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 static int 195 comparealiases(const void *p1, const void *p2) 196 { 197 const struct alias *const *a1 = p1; 198 const struct alias *const *a2 = p2; 199 200 return strcmp((*a1)->name, (*a2)->name); 201 } 202 203 static void 204 printalias(const struct alias *a) 205 { 206 char *p; 207 208 out1fmt("%s=", a->name); 209 /* Don't print the space added above. */ 210 p = a->val + strlen(a->val) - 1; 211 *p = '\0'; 212 out1qstr(a->val); 213 *p = ' '; 214 out1c('\n'); 215 } 216 217 static void 218 printaliases(void) 219 { 220 int i, j; 221 struct alias **sorted, *ap; 222 223 sorted = ckmalloc(aliases * sizeof(*sorted)); 224 j = 0; 225 for (i = 0; i < ATABSIZE; i++) 226 for (ap = atab[i]; ap; ap = ap->next) 227 if (*ap->name != '\0') 228 sorted[j++] = ap; 229 qsort(sorted, aliases, sizeof(*sorted), comparealiases); 230 for (i = 0; i < aliases; i++) 231 printalias(sorted[i]); 232 ckfree(sorted); 233 } 234 235 int 236 aliascmd(int argc, char **argv) 237 { 238 char *n, *v; 239 int ret = 0; 240 struct alias *ap; 241 242 if (argc == 1) { 243 printaliases(); 244 return (0); 245 } 246 while ((n = *++argv) != NULL) { 247 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */ 248 if ((ap = lookupalias(n, 0)) == NULL) { 249 outfmt(out2, "alias: %s not found\n", n); 250 ret = 1; 251 } else 252 printalias(ap); 253 else { 254 *v++ = '\0'; 255 setalias(n, v); 256 } 257 } 258 259 return (ret); 260 } 261 262 int 263 unaliascmd(int argc __unused, char **argv __unused) 264 { 265 int i; 266 267 while ((i = nextopt("a")) != '\0') { 268 if (i == 'a') { 269 rmaliases(); 270 return (0); 271 } 272 } 273 for (i = 0; *argptr; argptr++) 274 i |= unalias(*argptr); 275 276 return (i); 277 } 278 279 STATIC struct alias ** 280 hashalias(const char *p) 281 { 282 unsigned int hashval; 283 284 hashval = *p << 4; 285 while (*p) 286 hashval+= *p++; 287 return &atab[hashval % ATABSIZE]; 288 } 289