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