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 "$FreeBSD$"; 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 marks 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->flag = 0; 113 ap->next = *app; 114 *app = ap; 115 INTON; 116 } 117 118 STATIC int 119 unalias(name) 120 char *name; 121 { 122 struct alias *ap, **app; 123 124 app = hashalias(name); 125 126 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 127 if (equal(name, ap->name)) { 128 /* 129 * if the alias is currently in use (i.e. its 130 * buffer is being used by the input routine) we 131 * just null out the name instead of freeing it. 132 * We could clear it out later, but this situation 133 * is so rare that it hardly seems worth it. 134 */ 135 if (ap->flag & ALIASINUSE) 136 *ap->name = '\0'; 137 else { 138 INTOFF; 139 *app = ap->next; 140 ckfree(ap->name); 141 ckfree(ap->val); 142 ckfree(ap); 143 INTON; 144 } 145 return (0); 146 } 147 } 148 149 return (1); 150 } 151 152 #ifdef mkinit 153 MKINIT void rmaliases(); 154 155 SHELLPROC { 156 rmaliases(); 157 } 158 #endif 159 160 void 161 rmaliases() { 162 struct alias *ap, *tmp; 163 int i; 164 165 INTOFF; 166 for (i = 0; i < ATABSIZE; i++) { 167 ap = atab[i]; 168 atab[i] = NULL; 169 while (ap) { 170 ckfree(ap->name); 171 ckfree(ap->val); 172 tmp = ap; 173 ap = ap->next; 174 ckfree(tmp); 175 } 176 } 177 INTON; 178 } 179 180 struct alias * 181 lookupalias(name, check) 182 char *name; 183 int check; 184 { 185 struct alias *ap = *hashalias(name); 186 187 for (; ap; ap = ap->next) { 188 if (equal(name, ap->name)) { 189 if (check && (ap->flag & ALIASINUSE)) 190 return (NULL); 191 return (ap); 192 } 193 } 194 195 return (NULL); 196 } 197 198 /* 199 * TODO - sort output 200 */ 201 int 202 aliascmd(argc, argv) 203 int argc; 204 char **argv; 205 { 206 char *n, *v; 207 int ret = 0; 208 struct alias *ap; 209 210 if (argc == 1) { 211 int i; 212 213 for (i = 0; i < ATABSIZE; i++) 214 for (ap = atab[i]; ap; ap = ap->next) { 215 if (*ap->name != '\0') 216 out1fmt("alias %s=%s\n", ap->name, ap->val); 217 } 218 return (0); 219 } 220 while ((n = *++argv) != NULL) { 221 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */ 222 if ((ap = lookupalias(n, 0)) == NULL) { 223 outfmt(out2, "alias: %s not found\n", n); 224 ret = 1; 225 } else 226 out1fmt("alias %s=%s\n", n, ap->val); 227 else { 228 *v++ = '\0'; 229 setalias(n, v); 230 } 231 } 232 233 return (ret); 234 } 235 236 int 237 unaliascmd(argc, argv) 238 int argc __unused; 239 char **argv __unused; 240 { 241 int i; 242 243 while ((i = nextopt("a")) != '\0') { 244 if (i == 'a') { 245 rmaliases(); 246 return (0); 247 } 248 } 249 for (i = 0; *argptr; argptr++) 250 i = unalias(*argptr); 251 252 return (i); 253 } 254 255 STATIC struct alias ** 256 hashalias(p) 257 char *p; 258 { 259 unsigned int hashval; 260 261 hashval = *p << 4; 262 while (*p) 263 hashval+= *p++; 264 return &atab[hashval % ATABSIZE]; 265 } 266