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 37 #ifndef lint 38 /*static char sccsid[] = "from: @(#)alias.c 8.1 (Berkeley) 5/31/93";*/ 39 static char *rcsid = "$Id: alias.c,v 1.4 1994/12/04 07:12:06 cgd Exp $"; 40 #endif /* not lint */ 41 42 #include "shell.h" 43 #include "input.h" 44 #include "output.h" 45 #include "error.h" 46 #include "memalloc.h" 47 #include "mystring.h" 48 #include "alias.h" 49 #include "options.h" /* XXX for argptr (should remove?) */ 50 51 #define ATABSIZE 39 52 53 struct alias *atab[ATABSIZE]; 54 55 STATIC struct alias **hashalias __P((char *)); 56 57 STATIC 58 void 59 setalias(name, val) 60 char *name, *val; 61 { 62 struct alias *ap, **app; 63 64 app = hashalias(name); 65 for (ap = *app; ap; ap = ap->next) { 66 if (equal(name, ap->name)) { 67 INTOFF; 68 ckfree(ap->val); 69 ap->val = savestr(val); 70 INTON; 71 return; 72 } 73 } 74 /* not found */ 75 INTOFF; 76 ap = ckmalloc(sizeof (struct alias)); 77 ap->name = savestr(name); 78 /* 79 * XXX - HACK: in order that the parser will not finish reading the 80 * alias value off the input before processing the next alias, we 81 * dummy up an extra space at the end of the alias. This is a crock 82 * and should be re-thought. The idea (if you feel inclined to help) 83 * is to avoid alias recursions. The mechanism used is: when 84 * expanding an alias, the value of the alias is pushed back on the 85 * input as a string and a pointer to the alias is stored with the 86 * string. The alias is marked as being in use. When the input 87 * routine finishes reading the string, it markes the alias not 88 * in use. The problem is synchronization with the parser. Since 89 * it reads ahead, the alias is marked not in use before the 90 * resulting token(s) is next checked for further alias sub. The 91 * H A C K is that we add a little fluff after the alias value 92 * so that the string will not be exhausted. This is a good 93 * idea ------- ***NOT*** 94 */ 95 #ifdef notyet 96 ap->val = savestr(val); 97 #else /* hack */ 98 { 99 int len = strlen(val); 100 ap->val = ckmalloc(len + 2); 101 memcpy(ap->val, val, len); 102 ap->val[len] = ' '; /* fluff */ 103 ap->val[len+1] = '\0'; 104 } 105 #endif 106 ap->next = *app; 107 *app = ap; 108 INTON; 109 } 110 111 STATIC int 112 unalias(name) 113 char *name; 114 { 115 struct alias *ap, **app; 116 117 app = hashalias(name); 118 119 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 120 if (equal(name, ap->name)) { 121 /* 122 * if the alias is currently in use (i.e. its 123 * buffer is being used by the input routine) we 124 * just null out the name instead of freeing it. 125 * We could clear it out later, but this situation 126 * is so rare that it hardly seems worth it. 127 */ 128 if (ap->flag & ALIASINUSE) 129 *ap->name = '\0'; 130 else { 131 INTOFF; 132 *app = ap->next; 133 ckfree(ap->name); 134 ckfree(ap->val); 135 ckfree(ap); 136 INTON; 137 } 138 return (0); 139 } 140 } 141 142 return (1); 143 } 144 145 #ifdef mkinit 146 MKINIT void rmaliases(); 147 148 SHELLPROC { 149 rmaliases(); 150 } 151 #endif 152 153 void 154 rmaliases() { 155 struct alias *ap, *tmp; 156 int i; 157 158 INTOFF; 159 for (i = 0; i < ATABSIZE; i++) { 160 ap = atab[i]; 161 atab[i] = NULL; 162 while (ap) { 163 ckfree(ap->name); 164 ckfree(ap->val); 165 tmp = ap; 166 ap = ap->next; 167 ckfree(tmp); 168 } 169 } 170 INTON; 171 } 172 173 struct alias * 174 lookupalias(name, check) 175 char *name; 176 int check; 177 { 178 struct alias *ap = *hashalias(name); 179 180 for (; ap; ap = ap->next) { 181 if (equal(name, ap->name)) { 182 if (check && (ap->flag & ALIASINUSE)) 183 return (NULL); 184 return (ap); 185 } 186 } 187 188 return (NULL); 189 } 190 191 /* 192 * TODO - sort output 193 */ 194 int 195 aliascmd(argc, argv) 196 int argc; 197 char **argv; 198 { 199 char *n, *v; 200 int ret = 0; 201 struct alias *ap; 202 203 if (argc == 1) { 204 int i; 205 206 for (i = 0; i < ATABSIZE; i++) 207 for (ap = atab[i]; ap; ap = ap->next) { 208 if (*ap->name != '\0') 209 out1fmt("alias %s=%s\n", ap->name, ap->val); 210 } 211 return (0); 212 } 213 while (n = *++argv) { 214 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */ 215 if ((ap = lookupalias(n, 0)) == NULL) { 216 outfmt(out2, "alias: %s not found\n", n); 217 ret = 1; 218 } else 219 out1fmt("alias %s=%s\n", n, ap->val); 220 else { 221 *v++ = '\0'; 222 setalias(n, v); 223 } 224 } 225 226 return (ret); 227 } 228 229 int 230 unaliascmd(argc, argv) 231 int argc; 232 char **argv; 233 { 234 int i; 235 236 while ((i = nextopt("a")) != '\0') { 237 if (i == 'a') { 238 rmaliases(); 239 return (0); 240 } 241 } 242 for (i = 0; *argptr; argptr++) 243 i = unalias(*argptr); 244 245 return (i); 246 } 247 248 STATIC struct alias ** 249 hashalias(p) 250 register char *p; 251 { 252 unsigned int hashval; 253 254 hashval = *p << 4; 255 while (*p) 256 hashval+= *p++; 257 return &atab[hashval % ATABSIZE]; 258 } 259