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. 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: head/bin/sh/alias.c 317039 2017-04-16 22:10:02Z jilles $"); 40 41 #include <stdlib.h> 42 #include "shell.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" 49 #include "builtins.h" 50 51 #define ATABSIZE 39 52 53 static struct alias *atab[ATABSIZE]; 54 static int aliases; 55 56 static void setalias(const char *, const char *); 57 static int unalias(const char *); 58 static struct alias **hashalias(const char *); 59 60 static 61 void 62 setalias(const char *name, const char *val) 63 { 64 struct alias *ap, **app; 65 66 unalias(name); 67 app = hashalias(name); 68 INTOFF; 69 ap = ckmalloc(sizeof (struct alias)); 70 ap->name = savestr(name); 71 ap->val = savestr(val); 72 ap->flag = 0; 73 ap->next = *app; 74 *app = ap; 75 aliases++; 76 INTON; 77 } 78 79 static void 80 freealias(struct alias *ap) 81 { 82 ckfree(ap->name); 83 ckfree(ap->val); 84 ckfree(ap); 85 } 86 87 static int 88 unalias(const char *name) 89 { 90 struct alias *ap, **app; 91 92 app = hashalias(name); 93 94 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 95 if (equal(name, ap->name)) { 96 /* 97 * if the alias is currently in use (i.e. its 98 * buffer is being used by the input routine) we 99 * just null out the name instead of freeing it. 100 * We could clear it out later, but this situation 101 * is so rare that it hardly seems worth it. 102 */ 103 if (ap->flag & ALIASINUSE) 104 *ap->name = '\0'; 105 else { 106 INTOFF; 107 *app = ap->next; 108 freealias(ap); 109 INTON; 110 } 111 aliases--; 112 return (0); 113 } 114 } 115 116 return (1); 117 } 118 119 static void 120 rmaliases(void) 121 { 122 struct alias *ap, **app; 123 int i; 124 125 INTOFF; 126 for (i = 0; i < ATABSIZE; i++) { 127 app = &atab[i]; 128 while (*app) { 129 ap = *app; 130 if (ap->flag & ALIASINUSE) { 131 *ap->name = '\0'; 132 app = &(*app)->next; 133 } else { 134 *app = ap->next; 135 freealias(ap); 136 } 137 } 138 } 139 aliases = 0; 140 INTON; 141 } 142 143 struct alias * 144 lookupalias(const char *name, int check) 145 { 146 struct alias *ap; 147 148 if (aliases == 0) 149 return (NULL); 150 for (ap = *hashalias(name); ap; ap = ap->next) { 151 if (equal(name, ap->name)) { 152 if (check && (ap->flag & ALIASINUSE)) 153 return (NULL); 154 return (ap); 155 } 156 } 157 158 return (NULL); 159 } 160 161 static int 162 comparealiases(const void *p1, const void *p2) 163 { 164 const struct alias *const *a1 = p1; 165 const struct alias *const *a2 = p2; 166 167 return strcmp((*a1)->name, (*a2)->name); 168 } 169 170 static void 171 printalias(const struct alias *a) 172 { 173 out1fmt("%s=", a->name); 174 out1qstr(a->val); 175 out1c('\n'); 176 } 177 178 static void 179 printaliases(void) 180 { 181 int i, j; 182 struct alias **sorted, *ap; 183 184 INTOFF; 185 sorted = ckmalloc(aliases * sizeof(*sorted)); 186 j = 0; 187 for (i = 0; i < ATABSIZE; i++) 188 for (ap = atab[i]; ap; ap = ap->next) 189 if (*ap->name != '\0') 190 sorted[j++] = ap; 191 qsort(sorted, aliases, sizeof(*sorted), comparealiases); 192 for (i = 0; i < aliases; i++) { 193 printalias(sorted[i]); 194 if (int_pending()) 195 break; 196 } 197 ckfree(sorted); 198 INTON; 199 } 200 201 int 202 aliascmd(int argc __unused, char **argv __unused) 203 { 204 char *n, *v; 205 int ret = 0; 206 struct alias *ap; 207 208 nextopt(""); 209 210 if (*argptr == NULL) { 211 printaliases(); 212 return (0); 213 } 214 while ((n = *argptr++) != NULL) { 215 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */ 216 if ((ap = lookupalias(n, 0)) == NULL) { 217 warning("%s: not found", n); 218 ret = 1; 219 } else 220 printalias(ap); 221 else { 222 *v++ = '\0'; 223 setalias(n, v); 224 } 225 } 226 227 return (ret); 228 } 229 230 int 231 unaliascmd(int argc __unused, char **argv __unused) 232 { 233 int i; 234 235 while ((i = nextopt("a")) != '\0') { 236 if (i == 'a') { 237 rmaliases(); 238 return (0); 239 } 240 } 241 for (i = 0; *argptr; argptr++) 242 i |= unalias(*argptr); 243 244 return (i); 245 } 246 247 static struct alias ** 248 hashalias(const char *p) 249 { 250 unsigned int hashval; 251 252 hashval = (unsigned char)*p << 4; 253 while (*p) 254 hashval+= *p++; 255 return &atab[hashval % ATABSIZE]; 256 } 257