1 /* $NetBSD: alias.c,v 1.10 1998/05/20 00:27:56 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #ifndef lint 41 #if 0 42 static char sccsid[] = "@(#)alias.c 8.3 (Berkeley) 5/4/95"; 43 #else 44 __RCSID("$NetBSD: alias.c,v 1.10 1998/05/20 00:27:56 christos Exp $"); 45 #endif 46 #endif /* not lint */ 47 48 #include <stdlib.h> 49 #include "shell.h" 50 #include "input.h" 51 #include "output.h" 52 #include "error.h" 53 #include "memalloc.h" 54 #include "mystring.h" 55 #include "alias.h" 56 #include "options.h" /* XXX for argptr (should remove?) */ 57 58 #define ATABSIZE 39 59 60 struct alias *atab[ATABSIZE]; 61 62 STATIC void setalias __P((char *, char *)); 63 STATIC int unalias __P((char *)); 64 STATIC struct alias **hashalias __P((char *)); 65 66 STATIC 67 void 68 setalias(name, val) 69 char *name, *val; 70 { 71 struct alias *ap, **app; 72 73 app = hashalias(name); 74 for (ap = *app; ap; ap = ap->next) { 75 if (equal(name, ap->name)) { 76 INTOFF; 77 ckfree(ap->val); 78 ap->val = savestr(val); 79 INTON; 80 return; 81 } 82 } 83 /* not found */ 84 INTOFF; 85 ap = ckmalloc(sizeof (struct alias)); 86 ap->name = savestr(name); 87 /* 88 * XXX - HACK: in order that the parser will not finish reading the 89 * alias value off the input before processing the next alias, we 90 * dummy up an extra space at the end of the alias. This is a crock 91 * and should be re-thought. The idea (if you feel inclined to help) 92 * is to avoid alias recursions. The mechanism used is: when 93 * expanding an alias, the value of the alias is pushed back on the 94 * input as a string and a pointer to the alias is stored with the 95 * string. The alias is marked as being in use. When the input 96 * routine finishes reading the string, it markes the alias not 97 * in use. The problem is synchronization with the parser. Since 98 * it reads ahead, the alias is marked not in use before the 99 * resulting token(s) is next checked for further alias sub. The 100 * H A C K is that we add a little fluff after the alias value 101 * so that the string will not be exhausted. This is a good 102 * idea ------- ***NOT*** 103 */ 104 #ifdef notyet 105 ap->val = savestr(val); 106 #else /* hack */ 107 { 108 int len = strlen(val); 109 ap->val = ckmalloc(len + 2); 110 memcpy(ap->val, val, len); 111 ap->val[len] = ' '; /* fluff */ 112 ap->val[len+1] = '\0'; 113 } 114 #endif 115 ap->next = *app; 116 *app = ap; 117 INTON; 118 } 119 120 STATIC int 121 unalias(name) 122 char *name; 123 { 124 struct alias *ap, **app; 125 126 app = hashalias(name); 127 128 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 129 if (equal(name, ap->name)) { 130 /* 131 * if the alias is currently in use (i.e. its 132 * buffer is being used by the input routine) we 133 * just null out the name instead of freeing it. 134 * We could clear it out later, but this situation 135 * is so rare that it hardly seems worth it. 136 */ 137 if (ap->flag & ALIASINUSE) 138 *ap->name = '\0'; 139 else { 140 INTOFF; 141 *app = ap->next; 142 ckfree(ap->name); 143 ckfree(ap->val); 144 ckfree(ap); 145 INTON; 146 } 147 return (0); 148 } 149 } 150 151 return (1); 152 } 153 154 #ifdef mkinit 155 MKINIT void rmaliases __P((void)); 156 157 SHELLPROC { 158 rmaliases(); 159 } 160 #endif 161 162 void 163 rmaliases() { 164 struct alias *ap, *tmp; 165 int i; 166 167 INTOFF; 168 for (i = 0; i < ATABSIZE; i++) { 169 ap = atab[i]; 170 atab[i] = NULL; 171 while (ap) { 172 ckfree(ap->name); 173 ckfree(ap->val); 174 tmp = ap; 175 ap = ap->next; 176 ckfree(tmp); 177 } 178 } 179 INTON; 180 } 181 182 struct alias * 183 lookupalias(name, check) 184 char *name; 185 int check; 186 { 187 struct alias *ap = *hashalias(name); 188 189 for (; ap; ap = ap->next) { 190 if (equal(name, ap->name)) { 191 if (check && (ap->flag & ALIASINUSE)) 192 return (NULL); 193 return (ap); 194 } 195 } 196 197 return (NULL); 198 } 199 200 /* 201 * TODO - sort output 202 */ 203 int 204 aliascmd(argc, argv) 205 int argc; 206 char **argv; 207 { 208 char *n, *v; 209 int ret = 0; 210 struct alias *ap; 211 212 if (argc == 1) { 213 int i; 214 215 for (i = 0; i < ATABSIZE; i++) 216 for (ap = atab[i]; ap; ap = ap->next) { 217 if (*ap->name != '\0') 218 out1fmt("alias %s=%s\n", ap->name, ap->val); 219 } 220 return (0); 221 } 222 while ((n = *++argv) != NULL) { 223 if ((v = strchr(n+1, '=')) == NULL) { /* n+1: funny ksh stuff */ 224 if ((ap = lookupalias(n, 0)) == NULL) { 225 outfmt(out2, "alias: %s not found\n", n); 226 ret = 1; 227 } else 228 out1fmt("alias %s=%s\n", n, ap->val); 229 } 230 else { 231 *v++ = '\0'; 232 setalias(n, v); 233 } 234 } 235 236 return (ret); 237 } 238 239 int 240 unaliascmd(argc, argv) 241 int argc; 242 char **argv; 243 { 244 int i; 245 246 while ((i = nextopt("a")) != '\0') { 247 if (i == 'a') { 248 rmaliases(); 249 return (0); 250 } 251 } 252 for (i = 0; *argptr; argptr++) 253 i = unalias(*argptr); 254 255 return (i); 256 } 257 258 STATIC struct alias ** 259 hashalias(p) 260 char *p; 261 { 262 unsigned int hashval; 263 264 hashval = *p << 4; 265 while (*p) 266 hashval+= *p++; 267 return &atab[hashval % ATABSIZE]; 268 } 269