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 * $Id: alias.c,v 1.7 1997/02/22 13:58:20 peter Exp $ 37 */ 38 39 #ifndef lint 40 static char const sccsid[] = "@(#)alias.c 8.3 (Berkeley) 5/4/95"; 41 #endif /* not lint */ 42 43 #include <stdlib.h> 44 #include "shell.h" 45 #include "input.h" 46 #include "output.h" 47 #include "error.h" 48 #include "memalloc.h" 49 #include "mystring.h" 50 #include "alias.h" 51 #include "options.h" /* XXX for argptr (should remove?) */ 52 53 #define ATABSIZE 39 54 55 struct alias *atab[ATABSIZE]; 56 57 STATIC void setalias __P((char *, char *)); 58 STATIC int unalias __P((char *)); 59 STATIC struct alias **hashalias __P((char *)); 60 61 STATIC 62 void 63 setalias(name, val) 64 char *name, *val; 65 { 66 struct alias *ap, **app; 67 68 app = hashalias(name); 69 for (ap = *app; ap; ap = ap->next) { 70 if (equal(name, ap->name)) { 71 INTOFF; 72 ckfree(ap->val); 73 ap->val = savestr(val); 74 INTON; 75 return; 76 } 77 } 78 /* not found */ 79 INTOFF; 80 ap = ckmalloc(sizeof (struct alias)); 81 ap->name = savestr(name); 82 /* 83 * XXX - HACK: in order that the parser will not finish reading the 84 * alias value off the input before processing the next alias, we 85 * dummy up an extra space at the end of the alias. This is a crock 86 * and should be re-thought. The idea (if you feel inclined to help) 87 * is to avoid alias recursions. The mechanism used is: when 88 * expanding an alias, the value of the alias is pushed back on the 89 * input as a string and a pointer to the alias is stored with the 90 * string. The alias is marked as being in use. When the input 91 * routine finishes reading the string, it markes the alias not 92 * in use. The problem is synchronization with the parser. Since 93 * it reads ahead, the alias is marked not in use before the 94 * resulting token(s) is next checked for further alias sub. The 95 * H A C K is that we add a little fluff after the alias value 96 * so that the string will not be exhausted. This is a good 97 * idea ------- ***NOT*** 98 */ 99 #ifdef notyet 100 ap->val = savestr(val); 101 #else /* hack */ 102 { 103 int len = strlen(val); 104 ap->val = ckmalloc(len + 2); 105 memcpy(ap->val, val, len); 106 ap->val[len] = ' '; /* fluff */ 107 ap->val[len+1] = '\0'; 108 } 109 #endif 110 ap->next = *app; 111 *app = ap; 112 INTON; 113 } 114 115 STATIC int 116 unalias(name) 117 char *name; 118 { 119 struct alias *ap, **app; 120 121 app = hashalias(name); 122 123 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 124 if (equal(name, ap->name)) { 125 /* 126 * if the alias is currently in use (i.e. its 127 * buffer is being used by the input routine) we 128 * just null out the name instead of freeing it. 129 * We could clear it out later, but this situation 130 * is so rare that it hardly seems worth it. 131 */ 132 if (ap->flag & ALIASINUSE) 133 *ap->name = '\0'; 134 else { 135 INTOFF; 136 *app = ap->next; 137 ckfree(ap->name); 138 ckfree(ap->val); 139 ckfree(ap); 140 INTON; 141 } 142 return (0); 143 } 144 } 145 146 return (1); 147 } 148 149 #ifdef mkinit 150 MKINIT void rmaliases(); 151 152 SHELLPROC { 153 rmaliases(); 154 } 155 #endif 156 157 void 158 rmaliases() { 159 struct alias *ap, *tmp; 160 int i; 161 162 INTOFF; 163 for (i = 0; i < ATABSIZE; i++) { 164 ap = atab[i]; 165 atab[i] = NULL; 166 while (ap) { 167 ckfree(ap->name); 168 ckfree(ap->val); 169 tmp = ap; 170 ap = ap->next; 171 ckfree(tmp); 172 } 173 } 174 INTON; 175 } 176 177 struct alias * 178 lookupalias(name, check) 179 char *name; 180 int check; 181 { 182 struct alias *ap = *hashalias(name); 183 184 for (; ap; ap = ap->next) { 185 if (equal(name, ap->name)) { 186 if (check && (ap->flag & ALIASINUSE)) 187 return (NULL); 188 return (ap); 189 } 190 } 191 192 return (NULL); 193 } 194 195 /* 196 * TODO - sort output 197 */ 198 int 199 aliascmd(argc, argv) 200 int argc; 201 char **argv; 202 { 203 char *n, *v; 204 int ret = 0; 205 struct alias *ap; 206 207 if (argc == 1) { 208 int i; 209 210 for (i = 0; i < ATABSIZE; i++) 211 for (ap = atab[i]; ap; ap = ap->next) { 212 if (*ap->name != '\0') 213 out1fmt("alias %s=%s\n", ap->name, ap->val); 214 } 215 return (0); 216 } 217 while ((n = *++argv) != NULL) { 218 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */ 219 if ((ap = lookupalias(n, 0)) == NULL) { 220 outfmt(out2, "alias: %s not found\n", n); 221 ret = 1; 222 } else 223 out1fmt("alias %s=%s\n", n, ap->val); 224 else { 225 *v++ = '\0'; 226 setalias(n, v); 227 } 228 } 229 230 return (ret); 231 } 232 233 int 234 unaliascmd(argc, argv) 235 int argc; 236 char **argv; 237 { 238 int i; 239 240 while ((i = nextopt("a")) != '\0') { 241 if (i == 'a') { 242 rmaliases(); 243 return (0); 244 } 245 } 246 for (i = 0; *argptr; argptr++) 247 i = unalias(*argptr); 248 249 return (i); 250 } 251 252 STATIC struct alias ** 253 hashalias(p) 254 char *p; 255 { 256 unsigned int hashval; 257 258 hashval = *p << 4; 259 while (*p) 260 hashval+= *p++; 261 return &atab[hashval % ATABSIZE]; 262 } 263