1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Kenneth Almquist.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <stdlib.h>
36#include "shell.h"
37#include "output.h"
38#include "error.h"
39#include "memalloc.h"
40#include "mystring.h"
41#include "alias.h"
42#include "options.h"
43#include "builtins.h"
44
45#define ATABSIZE 39
46
47static struct alias *atab[ATABSIZE];
48static int aliases;
49
50static void setalias(const char *, const char *);
51static int unalias(const char *);
52static size_t hashalias(const char *);
53
54static
55void
56setalias(const char *name, const char *val)
57{
58 struct alias *ap, **app;
59
60 unalias(name);
61 app = &atab[hashalias(name)];
62 INTOFF;
63 ap = ckmalloc(sizeof (struct alias));
64 ap->name = savestr(name);
65 ap->val = savestr(val);
66 ap->flag = 0;
67 ap->next = *app;
68 *app = ap;
69 aliases++;
70 INTON;
71}
72
73static void
74freealias(struct alias *ap)
75{
76 ckfree(ap->name);
77 ckfree(ap->val);
78 ckfree(ap);
79}
80
81static int
82unalias(const char *name)
83{
84 struct alias *ap, **app;
85
86 app = &atab[hashalias(name)];
87
88 for (ap = *app; ap; app = &(ap->next), ap = ap->next) {
89 if (equal(name, ap->name)) {
90 /*
91 * if the alias is currently in use (i.e. its
92 * buffer is being used by the input routine) we
93 * just null out the name instead of freeing it.
94 * We could clear it out later, but this situation
95 * is so rare that it hardly seems worth it.
96 */
97 if (ap->flag & ALIASINUSE)
98 *ap->name = '\0';
99 else {
100 INTOFF;
101 *app = ap->next;
102 freealias(ap);
103 INTON;
104 }
105 aliases--;
106 return (0);
107 }
108 }
109
110 return (1);
111}
112
113static void
114rmaliases(void)
115{
116 struct alias *ap, **app;
117 int i;
118
119 INTOFF;
120 for (i = 0; i < ATABSIZE; i++) {
121 app = &atab[i];
122 while (*app) {
123 ap = *app;
124 if (ap->flag & ALIASINUSE) {
125 *ap->name = '\0';
126 app = &(*app)->next;
127 } else {
128 *app = ap->next;
129 freealias(ap);
130 }
131 }
132 }
133 aliases = 0;
134 INTON;
135}
136
137struct alias *
138lookupalias(const char *name, int check)
139{
140 struct alias *ap;
141
142 if (aliases == 0)
143 return (NULL);
144 for (ap = atab[hashalias(name)]; ap; ap = ap->next) {
145 if (equal(name, ap->name)) {
146 if (check && (ap->flag & ALIASINUSE))
147 return (NULL);
148 return (ap);
149 }
150 }
151
152 return (NULL);
153}
154
155static int
156comparealiases(const void *p1, const void *p2)
157{
158 const struct alias *const *a1 = p1;
159 const struct alias *const *a2 = p2;
160
161 return strcmp((*a1)->name, (*a2)->name);
162}
163
164static void
165printalias(const struct alias *a)
166{
167 out1fmt("%s=", a->name);
168 out1qstr(a->val);
169 out1c('\n');
170}
171
172static void
173printaliases(void)
174{
175 int i, j;
176 struct alias **sorted, *ap;
177
178 INTOFF;
179 sorted = ckmalloc(aliases * sizeof(*sorted));
180 j = 0;
181 for (i = 0; i < ATABSIZE; i++)
182 for (ap = atab[i]; ap; ap = ap->next)
183 if (*ap->name != '\0')
184 sorted[j++] = ap;
185 qsort(sorted, aliases, sizeof(*sorted), comparealiases);
186 for (i = 0; i < aliases; i++) {
187 printalias(sorted[i]);
188 if (int_pending())
189 break;
190 }
191 ckfree(sorted);
192 INTON;
193}
194
195int
196aliascmd(int argc __unused, char **argv __unused)
197{
198 char *n, *v;
199 int ret = 0;
200 struct alias *ap;
201
202 nextopt("");
203
204 if (*argptr == NULL) {
205 printaliases();
206 return (0);
207 }
208 while ((n = *argptr++) != NULL) {
209 if (n[0] == '\0') {
210 warning("'': not found");
211 ret = 1;
212 continue;
213 }
214 if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */
215 if ((ap = lookupalias(n, 0)) == NULL) {
216 warning("%s: not found", n);
217 ret = 1;
218 } else
219 printalias(ap);
220 else {
221 *v++ = '\0';
222 setalias(n, v);
223 }
224 }
225
226 return (ret);
227}
228
229int
230unaliascmd(int argc __unused, char **argv __unused)
231{
232 int i;
233
234 while ((i = nextopt("a")) != '\0') {
235 if (i == 'a') {
236 rmaliases();
237 return (0);
238 }
239 }
240 for (i = 0; *argptr; argptr++)
241 i |= unalias(*argptr);
242
243 return (i);
244}
245
246static size_t
247hashalias(const char *p)
248{
249 unsigned int hashval;
250
251 hashval = (unsigned char)*p << 4;
252 while (*p)
253 hashval+= *p++;
254 return (hashval % ATABSIZE);
255}
256
257const struct alias *
258iteralias(const struct alias *index)
259{
260 size_t i = 0;
261
262 if (index != NULL) {
263 if (index->next != NULL)
264 return (index->next);
265 i = hashalias(index->name) + 1;
266 }
267 for (; i < ATABSIZE; i++)
268 if (atab[i] != NULL)
269 return (atab[i]);
270
271 return (NULL);
272}
