1 /* $NetBSD: alias.c,v 1.7 1996/10/16 15:45:03 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 #ifndef lint 40 #if 0 41 static char sccsid[] = "@(#)alias.c 8.3 (Berkeley) 5/4/95"; 42 #else 43 static char rcsid[] = "$NetBSD: alias.c,v 1.7 1996/10/16 15:45:03 christos Exp $"; 44 #endif 45 #endif /* not lint */ 46 47 #include <stdlib.h> 48 #include "shell.h" 49 #include "input.h" 50 #include "output.h" 51 #include "error.h" 52 #include "memalloc.h" 53 #include "mystring.h" 54 #include "alias.h" 55 #include "options.h" /* XXX for argptr (should remove?) */ 56 57 #define ATABSIZE 39 58 59 struct alias *atab[ATABSIZE]; 60 61 STATIC void setalias __P((char *, char *)); 62 STATIC int unalias __P((char *)); 63 STATIC struct alias **hashalias __P((char *)); 64 65 STATIC 66 void 67 setalias(name, val) 68 char *name, *val; 69 { 70 struct alias *ap, **app; 71 72 app = hashalias(name); 73 for (ap = *app; ap; ap = ap->next) { 74 if (equal(name, ap->name)) { 75 INTOFF; 76 ckfree(ap->val); 77 ap->val = savestr(val); 78 INTON; 79 return; 80 } 81 } 82 /* not found */ 83 INTOFF; 84 ap = ckmalloc(sizeof (struct alias)); 85 ap->name = savestr(name); 86 /* 87 * XXX - HACK: in order that the parser will not finish reading the 88 * alias value off the input before processing the next alias, we 89 * dummy up an extra space at the end of the alias. This is a crock 90 * and should be re-thought. The idea (if you feel inclined to help) 91 * is to avoid alias recursions. The mechanism used is: when 92 * expanding an alias, the value of the alias is pushed back on the 93 * input as a string and a pointer to the alias is stored with the 94 * string. The alias is marked as being in use. When the input 95 * routine finishes reading the string, it markes the alias not 96 * in use. The problem is synchronization with the parser. Since 97 * it reads ahead, the alias is marked not in use before the 98 * resulting token(s) is next checked for further alias sub. The 99 * H A C K is that we add a little fluff after the alias value 100 * so that the string will not be exhausted. This is a good 101 * idea ------- ***NOT*** 102 */ 103 #ifdef notyet 104 ap->val = savestr(val); 105 #else /* hack */ 106 { 107 int len = strlen(val); 108 ap->val = ckmalloc(len + 2); 109 memcpy(ap->val, val, len); 110 ap->val[len] = ' '; /* fluff */ 111 ap->val[len+1] = '\0'; 112 } 113 #endif 114 ap->next = *app; 115 *app = ap; 116 INTON; 117 } 118 119 STATIC int 120 unalias(name) 121 char *name; 122 { 123 struct alias *ap, **app; 124 125 app = hashalias(name); 126 127 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 128 if (equal(name, ap->name)) { 129 /* 130 * if the alias is currently in use (i.e. its 131 * buffer is being used by the input routine) we 132 * just null out the name instead of freeing it. 133 * We could clear it out later, but this situation 134 * is so rare that it hardly seems worth it. 135 */ 136 if (ap->flag & ALIASINUSE) 137 *ap->name = '\0'; 138 else { 139 INTOFF; 140 *app = ap->next; 141 ckfree(ap->name); 142 ckfree(ap->val); 143 ckfree(ap); 144 INTON; 145 } 146 return (0); 147 } 148 } 149 150 return (1); 151 } 152 153 #ifdef mkinit 154 MKINIT void rmaliases(); 155 156 SHELLPROC { 157 rmaliases(); 158 } 159 #endif 160 161 void 162 rmaliases() { 163 struct alias *ap, *tmp; 164 int i; 165 166 INTOFF; 167 for (i = 0; i < ATABSIZE; i++) { 168 ap = atab[i]; 169 atab[i] = NULL; 170 while (ap) { 171 ckfree(ap->name); 172 ckfree(ap->val); 173 tmp = ap; 174 ap = ap->next; 175 ckfree(tmp); 176 } 177 } 178 INTON; 179 } 180 181 struct alias * 182 lookupalias(name, check) 183 char *name; 184 int check; 185 { 186 struct alias *ap = *hashalias(name); 187 188 for (; ap; ap = ap->next) { 189 if (equal(name, ap->name)) { 190 if (check && (ap->flag & ALIASINUSE)) 191 return (NULL); 192 return (ap); 193 } 194 } 195 196 return (NULL); 197 } 198 199 /* 200 * TODO - sort output 201 */ 202 int 203 aliascmd(argc, argv) 204 int argc; 205 char **argv; 206 { 207 char *n, *v; 208 int ret = 0; 209 struct alias *ap; 210 211 if (argc == 1) { 212 int i; 213 214 for (i = 0; i < ATABSIZE; i++) 215 for (ap = atab[i]; ap; ap = ap->next) { 216 if (*ap->name != '\0') 217 out1fmt("alias %s=%s\n", ap->name, ap->val); 218 } 219 return (0); 220 } 221 while ((n = *++argv) != NULL) { 222 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */ 223 if ((ap = lookupalias(n, 0)) == NULL) { 224 outfmt(out2, "alias: %s not found\n", n); 225 ret = 1; 226 } else 227 out1fmt("alias %s=%s\n", n, ap->val); 228 else { 229 *v++ = '\0'; 230 setalias(n, v); 231 } 232 } 233 234 return (ret); 235 } 236 237 int 238 unaliascmd(argc, argv) 239 int argc; 240 char **argv; 241 { 242 int i; 243 244 while ((i = nextopt("a")) != '\0') { 245 if (i == 'a') { 246 rmaliases(); 247 return (0); 248 } 249 } 250 for (i = 0; *argptr; argptr++) 251 i = unalias(*argptr); 252 253 return (i); 254 } 255 256 STATIC struct alias ** 257 hashalias(p) 258 register char *p; 259 { 260 unsigned int hashval; 261 262 hashval = *p << 4; 263 while (*p) 264 hashval+= *p++; 265 return &atab[hashval % ATABSIZE]; 266 } 267