1 /* $NetBSD: alias.c,v 1.5 1995/03/21 09:08:40 cgd 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 #ifndef lint 40 #if 0 41 static char sccsid[] = "@(#)alias.c 8.1 (Berkeley) 5/31/93"; 42 #else 43 static char rcsid[] = "$NetBSD: alias.c,v 1.5 1995/03/21 09:08:40 cgd Exp $"; 44 #endif 45 #endif /* not lint */ 46 47 #include "shell.h" 48 #include "input.h" 49 #include "output.h" 50 #include "error.h" 51 #include "memalloc.h" 52 #include "mystring.h" 53 #include "alias.h" 54 #include "options.h" /* XXX for argptr (should remove?) */ 55 56 #define ATABSIZE 39 57 58 struct alias *atab[ATABSIZE]; 59 60 STATIC struct alias **hashalias __P((char *)); 61 62 STATIC 63 void 64 setalias(name, val) 65 char *name, *val; 66 { 67 struct alias *ap, **app; 68 69 app = hashalias(name); 70 for (ap = *app; ap; ap = ap->next) { 71 if (equal(name, ap->name)) { 72 INTOFF; 73 ckfree(ap->val); 74 ap->val = savestr(val); 75 INTON; 76 return; 77 } 78 } 79 /* not found */ 80 INTOFF; 81 ap = ckmalloc(sizeof (struct alias)); 82 ap->name = savestr(name); 83 /* 84 * XXX - HACK: in order that the parser will not finish reading the 85 * alias value off the input before processing the next alias, we 86 * dummy up an extra space at the end of the alias. This is a crock 87 * and should be re-thought. The idea (if you feel inclined to help) 88 * is to avoid alias recursions. The mechanism used is: when 89 * expanding an alias, the value of the alias is pushed back on the 90 * input as a string and a pointer to the alias is stored with the 91 * string. The alias is marked as being in use. When the input 92 * routine finishes reading the string, it markes the alias not 93 * in use. The problem is synchronization with the parser. Since 94 * it reads ahead, the alias is marked not in use before the 95 * resulting token(s) is next checked for further alias sub. The 96 * H A C K is that we add a little fluff after the alias value 97 * so that the string will not be exhausted. This is a good 98 * idea ------- ***NOT*** 99 */ 100 #ifdef notyet 101 ap->val = savestr(val); 102 #else /* hack */ 103 { 104 int len = strlen(val); 105 ap->val = ckmalloc(len + 2); 106 memcpy(ap->val, val, len); 107 ap->val[len] = ' '; /* fluff */ 108 ap->val[len+1] = '\0'; 109 } 110 #endif 111 ap->next = *app; 112 *app = ap; 113 INTON; 114 } 115 116 STATIC int 117 unalias(name) 118 char *name; 119 { 120 struct alias *ap, **app; 121 122 app = hashalias(name); 123 124 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 125 if (equal(name, ap->name)) { 126 /* 127 * if the alias is currently in use (i.e. its 128 * buffer is being used by the input routine) we 129 * just null out the name instead of freeing it. 130 * We could clear it out later, but this situation 131 * is so rare that it hardly seems worth it. 132 */ 133 if (ap->flag & ALIASINUSE) 134 *ap->name = '\0'; 135 else { 136 INTOFF; 137 *app = ap->next; 138 ckfree(ap->name); 139 ckfree(ap->val); 140 ckfree(ap); 141 INTON; 142 } 143 return (0); 144 } 145 } 146 147 return (1); 148 } 149 150 #ifdef mkinit 151 MKINIT void rmaliases(); 152 153 SHELLPROC { 154 rmaliases(); 155 } 156 #endif 157 158 void 159 rmaliases() { 160 struct alias *ap, *tmp; 161 int i; 162 163 INTOFF; 164 for (i = 0; i < ATABSIZE; i++) { 165 ap = atab[i]; 166 atab[i] = NULL; 167 while (ap) { 168 ckfree(ap->name); 169 ckfree(ap->val); 170 tmp = ap; 171 ap = ap->next; 172 ckfree(tmp); 173 } 174 } 175 INTON; 176 } 177 178 struct alias * 179 lookupalias(name, check) 180 char *name; 181 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 /* 197 * TODO - sort output 198 */ 199 int 200 aliascmd(argc, argv) 201 int argc; 202 char **argv; 203 { 204 char *n, *v; 205 int ret = 0; 206 struct alias *ap; 207 208 if (argc == 1) { 209 int i; 210 211 for (i = 0; i < ATABSIZE; i++) 212 for (ap = atab[i]; ap; ap = ap->next) { 213 if (*ap->name != '\0') 214 out1fmt("alias %s=%s\n", ap->name, ap->val); 215 } 216 return (0); 217 } 218 while (n = *++argv) { 219 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */ 220 if ((ap = lookupalias(n, 0)) == NULL) { 221 outfmt(out2, "alias: %s not found\n", n); 222 ret = 1; 223 } else 224 out1fmt("alias %s=%s\n", n, ap->val); 225 else { 226 *v++ = '\0'; 227 setalias(n, v); 228 } 229 } 230 231 return (ret); 232 } 233 234 int 235 unaliascmd(argc, argv) 236 int argc; 237 char **argv; 238 { 239 int i; 240 241 while ((i = nextopt("a")) != '\0') { 242 if (i == 'a') { 243 rmaliases(); 244 return (0); 245 } 246 } 247 for (i = 0; *argptr; argptr++) 248 i = unalias(*argptr); 249 250 return (i); 251 } 252 253 STATIC struct alias ** 254 hashalias(p) 255 register char *p; 256 { 257 unsigned int hashval; 258 259 hashval = *p << 4; 260 while (*p) 261 hashval+= *p++; 262 return &atab[hashval % ATABSIZE]; 263 } 264