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 #endif /* not lint */ 42 #include <sys/cdefs.h> 43 __FBSDID("$FreeBSD$"); 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(char *, char *); 60 STATIC int unalias(char *); 61 STATIC struct alias **hashalias(char *); 62 63 STATIC 64 void 65 setalias(char *name, char *val) 66 { 67 struct alias *ap, **app; 68 69 app = hashalias(name); 70 for (ap = *app; ap; ap = ap->next) { 71 if (equal(name, ap->name)) { 72 INTOFF; 73 ckfree(ap->val); 74 ap->val = savestr(val); 75 INTON; 76 return; 77 } 78 } 79 /* not found */ 80 INTOFF; 81 ap = ckmalloc(sizeof (struct alias)); 82 ap->name = savestr(name); 83 /* 84 * XXX - HACK: in order that the parser will not finish reading the 85 * alias value off the input before processing the next alias, we 86 * dummy up an extra space at the end of the alias. This is a crock 87 * and should be re-thought. The idea (if you feel inclined to help) 88 * is to avoid alias recursions. The mechanism used is: when 89 * expanding an alias, the value of the alias is pushed back on the 90 * input as a string and a pointer to the alias is stored with the 91 * string. The alias is marked as being in use. When the input 92 * routine finishes reading the string, it marks the alias not 93 * in use. The problem is synchronization with the parser. Since 94 * it reads ahead, the alias is marked not in use before the 95 * resulting token(s) is next checked for further alias sub. The 96 * H A C K is that we add a little fluff after the alias value 97 * so that the string will not be exhausted. This is a good 98 * idea ------- ***NOT*** 99 */ 100 #ifdef notyet 101 ap->val = savestr(val); 102 #else /* hack */ 103 { 104 int len = strlen(val); 105 ap->val = ckmalloc(len + 2); 106 memcpy(ap->val, val, len); 107 ap->val[len] = ' '; /* fluff */ 108 ap->val[len+1] = '\0'; 109 } 110 #endif 111 ap->flag = 0; 112 ap->next = *app; 113 *app = ap; 114 INTON; 115 } 116 117 STATIC int 118 unalias(char *name) 119 { 120 struct alias *ap, **app; 121 122 app = hashalias(name); 123 124 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 125 if (equal(name, ap->name)) { 126 /* 127 * if the alias is currently in use (i.e. its 128 * buffer is being used by the input routine) we 129 * just null out the name instead of freeing it. 130 * We could clear it out later, but this situation 131 * is so rare that it hardly seems worth it. 132 */ 133 if (ap->flag & ALIASINUSE) 134 *ap->name = '\0'; 135 else { 136 INTOFF; 137 *app = ap->next; 138 ckfree(ap->name); 139 ckfree(ap->val); 140 ckfree(ap); 141 INTON; 142 } 143 return (0); 144 } 145 } 146 147 return (1); 148 } 149 150 #ifdef mkinit 151 MKINIT void rmaliases(); 152 153 SHELLPROC { 154 rmaliases(); 155 } 156 #endif 157 158 void 159 rmaliases(void) 160 { 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(char *name, 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(int argc, char **argv) 200 { 201 char *n, *v; 202 int ret = 0; 203 struct alias *ap; 204 205 if (argc == 1) { 206 int i; 207 208 for (i = 0; i < ATABSIZE; i++) 209 for (ap = atab[i]; ap; ap = ap->next) { 210 if (*ap->name != '\0') { 211 out1fmt("alias %s=", ap->name); 212 out1qstr(ap->val); 213 out1c('\n'); 214 } 215 } 216 return (0); 217 } 218 while ((n = *++argv) != NULL) { 219 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */ 220 if ((ap = lookupalias(n, 0)) == NULL) { 221 outfmt(out2, "alias: %s not found\n", n); 222 ret = 1; 223 } else { 224 out1fmt("alias %s=", n); 225 out1qstr(ap->val); 226 out1c('\n'); 227 } 228 else { 229 *v++ = '\0'; 230 setalias(n, v); 231 } 232 } 233 234 return (ret); 235 } 236 237 int 238 unaliascmd(int argc __unused, 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(char *p) 256 { 257 unsigned int hashval; 258 259 hashval = *p << 4; 260 while (*p) 261 hashval+= *p++; 262 return &atab[hashval % ATABSIZE]; 263 } 264