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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)alias.c 8.3 (Berkeley) 5/4/95 37 * $FreeBSD: src/bin/sh/alias.c,v 1.30 2011/02/04 22:47:55 jilles Exp $ 38 */ 39 40 #include <stdlib.h> 41 #include "shell.h" 42 #include "output.h" 43 #include "error.h" 44 #include "memalloc.h" 45 #include "mystring.h" 46 #include "alias.h" 47 #include "options.h" /* XXX for argptr (should remove?) */ 48 49 #define ATABSIZE 39 50 51 static struct alias *atab[ATABSIZE]; 52 static int aliases; 53 54 static void setalias(const char *, const char *); 55 static int unalias(const char *); 56 static struct alias **hashalias(const char *); 57 58 static 59 void 60 setalias(const char *name, const char *val) 61 { 62 struct alias *ap, **app; 63 64 app = hashalias(name); 65 for (ap = *app; ap; ap = ap->next) { 66 if (equal(name, ap->name)) { 67 INTOFF; 68 ckfree(ap->val); 69 ap->val = savestr(val); 70 INTON; 71 return; 72 } 73 } 74 /* not found */ 75 INTOFF; 76 ap = ckmalloc(sizeof (struct alias)); 77 ap->name = savestr(name); 78 /* 79 * XXX - HACK: in order that the parser will not finish reading the 80 * alias value off the input before processing the next alias, we 81 * dummy up an extra space at the end of the alias. This is a crock 82 * and should be re-thought. The idea (if you feel inclined to help) 83 * is to avoid alias recursions. The mechanism used is: when 84 * expanding an alias, the value of the alias is pushed back on the 85 * input as a string and a pointer to the alias is stored with the 86 * string. The alias is marked as being in use. When the input 87 * routine finishes reading the string, it marks the alias not 88 * in use. The problem is synchronization with the parser. Since 89 * it reads ahead, the alias is marked not in use before the 90 * resulting token(s) is next checked for further alias sub. The 91 * H A C K is that we add a little fluff after the alias value 92 * so that the string will not be exhausted. This is a good 93 * idea ------- ***NOT*** 94 */ 95 #ifdef notyet 96 ap->val = savestr(val); 97 #else /* hack */ 98 { 99 size_t len = strlen(val); 100 ap->val = ckmalloc(len + 2); 101 memcpy(ap->val, val, len); 102 ap->val[len] = ' '; /* fluff */ 103 ap->val[len+1] = '\0'; 104 } 105 #endif 106 ap->flag = 0; 107 ap->next = *app; 108 *app = ap; 109 aliases++; 110 INTON; 111 } 112 113 static int 114 unalias(const char *name) 115 { 116 struct alias *ap, **app; 117 118 app = hashalias(name); 119 120 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 121 if (equal(name, ap->name)) { 122 /* 123 * if the alias is currently in use (i.e. its 124 * buffer is being used by the input routine) we 125 * just null out the name instead of freeing it. 126 * We could clear it out later, but this situation 127 * is so rare that it hardly seems worth it. 128 */ 129 if (ap->flag & ALIASINUSE) 130 *ap->name = '\0'; 131 else { 132 INTOFF; 133 *app = ap->next; 134 ckfree(ap->name); 135 ckfree(ap->val); 136 ckfree(ap); 137 INTON; 138 } 139 aliases--; 140 return (0); 141 } 142 } 143 144 return (1); 145 } 146 147 static void 148 rmaliases(void) 149 { 150 struct alias *ap, *tmp; 151 int i; 152 153 INTOFF; 154 for (i = 0; i < ATABSIZE; i++) { 155 ap = atab[i]; 156 atab[i] = NULL; 157 while (ap) { 158 ckfree(ap->name); 159 ckfree(ap->val); 160 tmp = ap; 161 ap = ap->next; 162 ckfree(tmp); 163 } 164 } 165 aliases = 0; 166 INTON; 167 } 168 169 struct alias * 170 lookupalias(const char *name, int check) 171 { 172 struct alias *ap = *hashalias(name); 173 174 for (; ap; ap = ap->next) { 175 if (equal(name, ap->name)) { 176 if (check && (ap->flag & ALIASINUSE)) 177 return (NULL); 178 return (ap); 179 } 180 } 181 182 return (NULL); 183 } 184 185 static int 186 comparealiases(const void *p1, const void *p2) 187 { 188 const struct alias *const *a1 = p1; 189 const struct alias *const *a2 = p2; 190 191 return strcmp((*a1)->name, (*a2)->name); 192 } 193 194 static void 195 printalias(const struct alias *a) 196 { 197 char *p; 198 199 out1fmt("%s=", a->name); 200 /* Don't print the space added above. */ 201 p = a->val + strlen(a->val) - 1; 202 *p = '\0'; 203 out1qstr(a->val); 204 *p = ' '; 205 out1c('\n'); 206 } 207 208 static void 209 printaliases(void) 210 { 211 int i, j; 212 struct alias **sorted, *ap; 213 214 sorted = ckmalloc(aliases * sizeof(*sorted)); 215 j = 0; 216 for (i = 0; i < ATABSIZE; i++) 217 for (ap = atab[i]; ap; ap = ap->next) 218 if (*ap->name != '\0') 219 sorted[j++] = ap; 220 qsort(sorted, aliases, sizeof(*sorted), comparealiases); 221 for (i = 0; i < aliases; i++) 222 printalias(sorted[i]); 223 ckfree(sorted); 224 } 225 226 int 227 aliascmd(int argc, char **argv) 228 { 229 char *n, *v; 230 int ret = 0; 231 struct alias *ap; 232 233 if (argc == 1) { 234 printaliases(); 235 return (0); 236 } 237 while ((n = *++argv) != NULL) { 238 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */ 239 if ((ap = lookupalias(n, 0)) == NULL) { 240 warning("%s not found", n); 241 ret = 1; 242 } else 243 printalias(ap); 244 else { 245 *v++ = '\0'; 246 setalias(n, v); 247 } 248 } 249 250 return (ret); 251 } 252 253 int 254 unaliascmd(int argc __unused, char **argv __unused) 255 { 256 int i; 257 258 while ((i = nextopt("a")) != '\0') { 259 if (i == 'a') { 260 rmaliases(); 261 return (0); 262 } 263 } 264 for (i = 0; *argptr; argptr++) 265 i |= unalias(*argptr); 266 267 return (i); 268 } 269 270 static struct alias ** 271 hashalias(const char *p) 272 { 273 unsigned int hashval; 274 275 hashval = *p << 4; 276 while (*p) 277 hashval+= *p++; 278 return &atab[hashval % ATABSIZE]; 279 } 280