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 1.32 2011/06/13 21:03:27 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 #include "builtins.h" 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 static void 149 rmaliases(void) 150 { 151 struct alias *ap, *tmp; 152 int i; 153 154 INTOFF; 155 for (i = 0; i < ATABSIZE; i++) { 156 ap = atab[i]; 157 atab[i] = NULL; 158 while (ap) { 159 ckfree(ap->name); 160 ckfree(ap->val); 161 tmp = ap; 162 ap = ap->next; 163 ckfree(tmp); 164 } 165 } 166 aliases = 0; 167 INTON; 168 } 169 170 struct alias * 171 lookupalias(const char *name, int check) 172 { 173 struct alias *ap = *hashalias(name); 174 175 for (; ap; ap = ap->next) { 176 if (equal(name, ap->name)) { 177 if (check && (ap->flag & ALIASINUSE)) 178 return (NULL); 179 return (ap); 180 } 181 } 182 183 return (NULL); 184 } 185 186 static int 187 comparealiases(const void *p1, const void *p2) 188 { 189 const struct alias *const *a1 = p1; 190 const struct alias *const *a2 = p2; 191 192 return strcmp((*a1)->name, (*a2)->name); 193 } 194 195 static void 196 printalias(const struct alias *a) 197 { 198 char *p; 199 200 out1fmt("%s=", a->name); 201 /* Don't print the space added above. */ 202 p = a->val + strlen(a->val) - 1; 203 *p = '\0'; 204 out1qstr(a->val); 205 *p = ' '; 206 out1c('\n'); 207 } 208 209 static void 210 printaliases(void) 211 { 212 int i, j; 213 struct alias **sorted, *ap; 214 215 sorted = ckmalloc(aliases * sizeof(*sorted)); 216 j = 0; 217 for (i = 0; i < ATABSIZE; i++) 218 for (ap = atab[i]; ap; ap = ap->next) 219 if (*ap->name != '\0') 220 sorted[j++] = ap; 221 qsort(sorted, aliases, sizeof(*sorted), comparealiases); 222 for (i = 0; i < aliases; i++) 223 printalias(sorted[i]); 224 ckfree(sorted); 225 } 226 227 int 228 aliascmd(int argc, char **argv) 229 { 230 char *n, *v; 231 int ret = 0; 232 struct alias *ap; 233 234 if (argc == 1) { 235 printaliases(); 236 return (0); 237 } 238 while ((n = *++argv) != NULL) { 239 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */ 240 if ((ap = lookupalias(n, 0)) == NULL) { 241 warning("%s: not found", n); 242 ret = 1; 243 } else 244 printalias(ap); 245 else { 246 *v++ = '\0'; 247 setalias(n, v); 248 } 249 } 250 251 return (ret); 252 } 253 254 int 255 unaliascmd(int argc __unused, char **argv __unused) 256 { 257 int i; 258 259 while ((i = nextopt("a")) != '\0') { 260 if (i == 'a') { 261 rmaliases(); 262 return (0); 263 } 264 } 265 for (i = 0; *argptr; argptr++) 266 i |= unalias(*argptr); 267 268 return (i); 269 } 270 271 static struct alias ** 272 hashalias(const char *p) 273 { 274 unsigned int hashval; 275 276 hashval = *p << 4; 277 while (*p) 278 hashval+= *p++; 279 return &atab[hashval % ATABSIZE]; 280 } 281