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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)alias.c 8.3 (Berkeley) 5/4/95"; 36 #endif 37 #endif /* not lint */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <stdlib.h> 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 STATIC struct alias *atab[ATABSIZE]; 54 55 STATIC void setalias(char *, char *); 56 STATIC int unalias(char *); 57 STATIC struct alias **hashalias(char *); 58 59 STATIC 60 void 61 setalias(char *name, char *val) 62 { 63 struct alias *ap, **app; 64 65 app = hashalias(name); 66 for (ap = *app; ap; ap = ap->next) { 67 if (equal(name, ap->name)) { 68 INTOFF; 69 ckfree(ap->val); 70 ap->val = savestr(val); 71 INTON; 72 return; 73 } 74 } 75 /* not found */ 76 INTOFF; 77 ap = ckmalloc(sizeof (struct alias)); 78 ap->name = savestr(name); 79 /* 80 * XXX - HACK: in order that the parser will not finish reading the 81 * alias value off the input before processing the next alias, we 82 * dummy up an extra space at the end of the alias. This is a crock 83 * and should be re-thought. The idea (if you feel inclined to help) 84 * is to avoid alias recursions. The mechanism used is: when 85 * expanding an alias, the value of the alias is pushed back on the 86 * input as a string and a pointer to the alias is stored with the 87 * string. The alias is marked as being in use. When the input 88 * routine finishes reading the string, it marks the alias not 89 * in use. The problem is synchronization with the parser. Since 90 * it reads ahead, the alias is marked not in use before the 91 * resulting token(s) is next checked for further alias sub. The 92 * H A C K is that we add a little fluff after the alias value 93 * so that the string will not be exhausted. This is a good 94 * idea ------- ***NOT*** 95 */ 96 #ifdef notyet 97 ap->val = savestr(val); 98 #else /* hack */ 99 { 100 int len = strlen(val); 101 ap->val = ckmalloc(len + 2); 102 memcpy(ap->val, val, len); 103 ap->val[len] = ' '; /* fluff */ 104 ap->val[len+1] = '\0'; 105 } 106 #endif 107 ap->flag = 0; 108 ap->next = *app; 109 *app = ap; 110 INTON; 111 } 112 113 STATIC int 114 unalias(char *name) 115 { 116 struct alias *ap, **app; 117 118 app = hashalias(name); 119 120 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 121 if (equal(name, ap->name)) { 122 /* 123 * if the alias is currently in use (i.e. its 124 * buffer is being used by the input routine) we 125 * just null out the name instead of freeing it. 126 * We could clear it out later, but this situation 127 * is so rare that it hardly seems worth it. 128 */ 129 if (ap->flag & ALIASINUSE) 130 *ap->name = '\0'; 131 else { 132 INTOFF; 133 *app = ap->next; 134 ckfree(ap->name); 135 ckfree(ap->val); 136 ckfree(ap); 137 INTON; 138 } 139 return (0); 140 } 141 } 142 143 return (1); 144 } 145 146 #ifdef mkinit 147 MKINIT void rmaliases(void); 148 149 SHELLPROC { 150 rmaliases(); 151 } 152 #endif 153 154 void 155 rmaliases(void) 156 { 157 struct alias *ap, *tmp; 158 int i; 159 160 INTOFF; 161 for (i = 0; i < ATABSIZE; i++) { 162 ap = atab[i]; 163 atab[i] = NULL; 164 while (ap) { 165 ckfree(ap->name); 166 ckfree(ap->val); 167 tmp = ap; 168 ap = ap->next; 169 ckfree(tmp); 170 } 171 } 172 INTON; 173 } 174 175 struct alias * 176 lookupalias(char *name, 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(int argc, char **argv) 196 { 197 char *n, *v; 198 int ret = 0; 199 struct alias *ap; 200 201 if (argc == 1) { 202 int i; 203 204 for (i = 0; i < ATABSIZE; i++) 205 for (ap = atab[i]; ap; ap = ap->next) { 206 if (*ap->name != '\0') { 207 out1fmt("alias %s=", ap->name); 208 out1qstr(ap->val); 209 out1c('\n'); 210 } 211 } 212 return (0); 213 } 214 while ((n = *++argv) != NULL) { 215 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */ 216 if ((ap = lookupalias(n, 0)) == NULL) { 217 outfmt(out2, "alias: %s not found\n", n); 218 ret = 1; 219 } else { 220 out1fmt("alias %s=", n); 221 out1qstr(ap->val); 222 out1c('\n'); 223 } 224 else { 225 *v++ = '\0'; 226 setalias(n, v); 227 } 228 } 229 230 return (ret); 231 } 232 233 int 234 unaliascmd(int argc __unused, char **argv __unused) 235 { 236 int i; 237 238 while ((i = nextopt("a")) != '\0') { 239 if (i == 'a') { 240 rmaliases(); 241 return (0); 242 } 243 } 244 for (i = 0; *argptr; argptr++) 245 i |= unalias(*argptr); 246 247 return (i); 248 } 249 250 STATIC struct alias ** 251 hashalias(char *p) 252 { 253 unsigned int hashval; 254 255 hashval = *p << 4; 256 while (*p) 257 hashval+= *p++; 258 return &atab[hashval % ATABSIZE]; 259 } 260