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