1 /* $NetBSD: alias.c,v 1.15 2014/06/18 18:17:30 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Kenneth Almquist. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #ifndef lint 37 #if 0 38 static char sccsid[] = "@(#)alias.c 8.3 (Berkeley) 5/4/95"; 39 #else 40 __RCSID("$NetBSD: alias.c,v 1.15 2014/06/18 18:17:30 christos Exp $"); 41 #endif 42 #endif /* not lint */ 43 44 #include <stdlib.h> 45 #include "shell.h" 46 #include "input.h" 47 #include "output.h" 48 #include "error.h" 49 #include "memalloc.h" 50 #include "mystring.h" 51 #include "alias.h" 52 #include "options.h" /* XXX for argptr (should remove?) */ 53 #include "builtins.h" 54 #include "var.h" 55 56 #define ATABSIZE 39 57 58 struct alias *atab[ATABSIZE]; 59 60 STATIC void setalias(char *, char *); 61 STATIC int unalias(char *); 62 STATIC struct alias **hashalias(const char *); 63 64 STATIC 65 void 66 setalias(char *name, char *val) 67 { 68 struct alias *ap, **app; 69 70 app = hashalias(name); 71 for (ap = *app; ap; ap = ap->next) { 72 if (equal(name, ap->name)) { 73 INTOFF; 74 ckfree(ap->val); 75 ap->val = savestr(val); 76 INTON; 77 return; 78 } 79 } 80 /* not found */ 81 INTOFF; 82 ap = ckmalloc(sizeof (struct alias)); 83 ap->name = savestr(name); 84 ap->flag = 0; 85 /* 86 * XXX - HACK: in order that the parser will not finish reading the 87 * alias value off the input before processing the next alias, we 88 * dummy up an extra space at the end of the alias. This is a crock 89 * and should be re-thought. The idea (if you feel inclined to help) 90 * is to avoid alias recursions. The mechanism used is: when 91 * expanding an alias, the value of the alias is pushed back on the 92 * input as a string and a pointer to the alias is stored with the 93 * string. The alias is marked as being in use. When the input 94 * routine finishes reading the string, it markes the alias not 95 * in use. The problem is synchronization with the parser. Since 96 * it reads ahead, the alias is marked not in use before the 97 * resulting token(s) is next checked for further alias sub. The 98 * H A C K is that we add a little fluff after the alias value 99 * so that the string will not be exhausted. This is a good 100 * idea ------- ***NOT*** 101 */ 102 #ifdef notyet 103 ap->val = savestr(val); 104 #else /* hack */ 105 { 106 int len = strlen(val); 107 ap->val = ckmalloc(len + 2); 108 memcpy(ap->val, val, len); 109 ap->val[len] = ' '; /* fluff */ 110 ap->val[len+1] = '\0'; 111 } 112 #endif 113 ap->next = *app; 114 *app = ap; 115 INTON; 116 } 117 118 STATIC int 119 unalias(char *name) 120 { 121 struct alias *ap, **app; 122 123 app = hashalias(name); 124 125 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 126 if (equal(name, ap->name)) { 127 /* 128 * if the alias is currently in use (i.e. its 129 * buffer is being used by the input routine) we 130 * just null out the name instead of freeing it. 131 * We could clear it out later, but this situation 132 * is so rare that it hardly seems worth it. 133 */ 134 if (ap->flag & ALIASINUSE) 135 *ap->name = '\0'; 136 else { 137 INTOFF; 138 *app = ap->next; 139 ckfree(ap->name); 140 ckfree(ap->val); 141 ckfree(ap); 142 INTON; 143 } 144 return (0); 145 } 146 } 147 148 return (1); 149 } 150 151 #ifdef mkinit 152 MKINIT void rmaliases(void); 153 154 SHELLPROC { 155 rmaliases(); 156 } 157 #endif 158 159 void 160 rmaliases(void) 161 { 162 struct alias *ap, *tmp; 163 int i; 164 165 INTOFF; 166 for (i = 0; i < ATABSIZE; i++) { 167 ap = atab[i]; 168 atab[i] = NULL; 169 while (ap) { 170 ckfree(ap->name); 171 ckfree(ap->val); 172 tmp = ap; 173 ap = ap->next; 174 ckfree(tmp); 175 } 176 } 177 INTON; 178 } 179 180 struct alias * 181 lookupalias(const char *name, int check) 182 { 183 struct alias *ap = *hashalias(name); 184 185 for (; ap; ap = ap->next) { 186 if (equal(name, ap->name)) { 187 if (check && (ap->flag & ALIASINUSE)) 188 return (NULL); 189 return (ap); 190 } 191 } 192 193 return (NULL); 194 } 195 196 const char * 197 alias_text(void *dummy __unused, const char *name) 198 { 199 struct alias *ap; 200 201 ap = lookupalias(name, 0); 202 if (ap == NULL) 203 return NULL; 204 return ap->val; 205 } 206 207 /* 208 * TODO - sort output 209 */ 210 int 211 aliascmd(int argc, char **argv) 212 { 213 char *n, *v; 214 int ret = 0; 215 struct alias *ap; 216 217 if (argc == 1) { 218 int i; 219 220 for (i = 0; i < ATABSIZE; i++) 221 for (ap = atab[i]; ap; ap = ap->next) { 222 if (*ap->name != '\0') { 223 out1fmt("alias %s=", ap->name); 224 print_quoted(ap->val); 225 out1c('\n'); 226 } 227 } 228 return (0); 229 } 230 while ((n = *++argv) != NULL) { 231 if ((v = strchr(n+1, '=')) == NULL) { /* n+1: funny ksh stuff */ 232 if ((ap = lookupalias(n, 0)) == NULL) { 233 outfmt(out2, "alias: %s not found\n", n); 234 ret = 1; 235 } else { 236 out1fmt("alias %s=", n); 237 print_quoted(ap->val); 238 out1c('\n'); 239 } 240 } else { 241 *v++ = '\0'; 242 setalias(n, v); 243 } 244 } 245 246 return (ret); 247 } 248 249 int 250 unaliascmd(int argc, char **argv) 251 { 252 int i; 253 254 while ((i = nextopt("a")) != '\0') { 255 if (i == 'a') { 256 rmaliases(); 257 return (0); 258 } 259 } 260 for (i = 0; *argptr; argptr++) 261 i = unalias(*argptr); 262 263 return (i); 264 } 265 266 STATIC struct alias ** 267 hashalias(const char *p) 268 { 269 unsigned int hashval; 270 271 hashval = *p << 4; 272 while (*p) 273 hashval+= *p++; 274 return &atab[hashval % ATABSIZE]; 275 } 276