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: stable/9/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
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
setalias(const char * name,const char * val)62 setalias(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
126 static int
unalias(const char * name)127 unalias(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
160 static void
rmaliases(void)161 rmaliases(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
182 struct alias *
lookupalias(const char * name,int check)183 lookupalias(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
198 static int
comparealiases(const void * p1,const void * p2)199 comparealiases(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
207 static void
printalias(const struct alias * a)208 printalias(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
221 static void
printaliases(void)222 printaliases(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
244 int
aliascmd(int argc,char ** argv)245 aliascmd(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
271 int
unaliascmd(int argc __unused,char ** argv __unused)272 unaliascmd(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
288 static struct alias **
hashalias(const char * p)289 hashalias(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