alias.c revision 267654
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 35static char sccsid[] = "@(#)alias.c 8.3 (Berkeley) 5/4/95"; 36#endif 37#endif /* not lint */ 38#include <sys/cdefs.h> 39__FBSDID("$FreeBSD: releng/9.3/bin/sh/alias.c 264629 2014-04-17 21:43:34Z 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" /* XXX for argptr (should remove?) */ 49#include "builtins.h" 50 51#define ATABSIZE 39 52 53static struct alias *atab[ATABSIZE]; 54static int aliases; 55 56static void setalias(const char *, const char *); 57static int unalias(const char *); 58static struct alias **hashalias(const char *); 59 60static 61void 62setalias(const char *name, const char *val) 63{ 64 struct alias *ap, **app; 65 66 app = hashalias(name); 67 for (ap = *app; ap; ap = ap->next) { 68 if (equal(name, ap->name)) { 69 INTOFF; 70 ckfree(ap->val); 71 /* See HACK below. */ 72#ifdef notyet 73 ap->val = savestr(val); 74#else 75 { 76 size_t len = strlen(val); 77 ap->val = ckmalloc(len + 2); 78 memcpy(ap->val, val, len); 79 ap->val[len] = ' '; 80 ap->val[len+1] = '\0'; 81 } 82#endif 83 INTON; 84 return; 85 } 86 } 87 /* not found */ 88 INTOFF; 89 ap = ckmalloc(sizeof (struct alias)); 90 ap->name = savestr(name); 91 /* 92 * XXX - HACK: in order that the parser will not finish reading the 93 * alias value off the input before processing the next alias, we 94 * dummy up an extra space at the end of the alias. This is a crock 95 * and should be re-thought. The idea (if you feel inclined to help) 96 * is to avoid alias recursions. The mechanism used is: when 97 * expanding an alias, the value of the alias is pushed back on the 98 * input as a string and a pointer to the alias is stored with the 99 * string. The alias is marked as being in use. When the input 100 * routine finishes reading the string, it marks the alias not 101 * in use. The problem is synchronization with the parser. Since 102 * it reads ahead, the alias is marked not in use before the 103 * resulting token(s) is next checked for further alias sub. The 104 * H A C K is that we add a little fluff after the alias value 105 * so that the string will not be exhausted. This is a good 106 * idea ------- ***NOT*** 107 */ 108#ifdef notyet 109 ap->val = savestr(val); 110#else /* hack */ 111 { 112 size_t len = strlen(val); 113 ap->val = ckmalloc(len + 2); 114 memcpy(ap->val, val, len); 115 ap->val[len] = ' '; /* fluff */ 116 ap->val[len+1] = '\0'; 117 } 118#endif 119 ap->flag = 0; 120 ap->next = *app; 121 *app = ap; 122 aliases++; 123 INTON; 124} 125 126static int 127unalias(const char *name) 128{ 129 struct alias *ap, **app; 130 131 app = hashalias(name); 132 133 for (ap = *app; ap; app = &(ap->next), ap = ap->next) { 134 if (equal(name, ap->name)) { 135 /* 136 * if the alias is currently in use (i.e. its 137 * buffer is being used by the input routine) we 138 * just null out the name instead of freeing it. 139 * We could clear it out later, but this situation 140 * is so rare that it hardly seems worth it. 141 */ 142 if (ap->flag & ALIASINUSE) 143 *ap->name = '\0'; 144 else { 145 INTOFF; 146 *app = ap->next; 147 ckfree(ap->name); 148 ckfree(ap->val); 149 ckfree(ap); 150 INTON; 151 } 152 aliases--; 153 return (0); 154 } 155 } 156 157 return (1); 158} 159 160static void 161rmaliases(void) 162{ 163 struct alias *ap, *tmp; 164 int i; 165 166 INTOFF; 167 for (i = 0; i < ATABSIZE; i++) { 168 ap = atab[i]; 169 atab[i] = NULL; 170 while (ap) { 171 ckfree(ap->name); 172 ckfree(ap->val); 173 tmp = ap; 174 ap = ap->next; 175 ckfree(tmp); 176 } 177 } 178 aliases = 0; 179 INTON; 180} 181 182struct alias * 183lookupalias(const char *name, 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 198static int 199comparealiases(const void *p1, const void *p2) 200{ 201 const struct alias *const *a1 = p1; 202 const struct alias *const *a2 = p2; 203 204 return strcmp((*a1)->name, (*a2)->name); 205} 206 207static void 208printalias(const struct alias *a) 209{ 210 char *p; 211 212 out1fmt("%s=", a->name); 213 /* Don't print the space added above. */ 214 p = a->val + strlen(a->val) - 1; 215 *p = '\0'; 216 out1qstr(a->val); 217 *p = ' '; 218 out1c('\n'); 219} 220 221static void 222printaliases(void) 223{ 224 int i, j; 225 struct alias **sorted, *ap; 226 227 INTOFF; 228 sorted = ckmalloc(aliases * sizeof(*sorted)); 229 j = 0; 230 for (i = 0; i < ATABSIZE; i++) 231 for (ap = atab[i]; ap; ap = ap->next) 232 if (*ap->name != '\0') 233 sorted[j++] = ap; 234 qsort(sorted, aliases, sizeof(*sorted), comparealiases); 235 for (i = 0; i < aliases; i++) { 236 printalias(sorted[i]); 237 if (int_pending()) 238 break; 239 } 240 ckfree(sorted); 241 INTON; 242} 243 244int 245aliascmd(int argc, char **argv) 246{ 247 char *n, *v; 248 int ret = 0; 249 struct alias *ap; 250 251 if (argc == 1) { 252 printaliases(); 253 return (0); 254 } 255 while ((n = *++argv) != NULL) { 256 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */ 257 if ((ap = lookupalias(n, 0)) == NULL) { 258 warning("%s: not found", n); 259 ret = 1; 260 } else 261 printalias(ap); 262 else { 263 *v++ = '\0'; 264 setalias(n, v); 265 } 266 } 267 268 return (ret); 269} 270 271int 272unaliascmd(int argc __unused, char **argv __unused) 273{ 274 int i; 275 276 while ((i = nextopt("a")) != '\0') { 277 if (i == 'a') { 278 rmaliases(); 279 return (0); 280 } 281 } 282 for (i = 0; *argptr; argptr++) 283 i |= unalias(*argptr); 284 285 return (i); 286} 287 288static struct alias ** 289hashalias(const char *p) 290{ 291 unsigned int hashval; 292 293 hashval = *p << 4; 294 while (*p) 295 hashval+= *p++; 296 return &atab[hashval % ATABSIZE]; 297} 298