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