xref: /freebsd/bin/sh/alias.c (revision cbd30a72ca196976c1c700400ecd424baa1b9c16)
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("$FreeBSD$");
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
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 			ap->val	= savestr(val);
72 			INTON;
73 			return;
74 		}
75 	}
76 	/* not found */
77 	INTOFF;
78 	ap = ckmalloc(sizeof (struct alias));
79 	ap->name = savestr(name);
80 	ap->val = savestr(val);
81 	ap->flag = 0;
82 	ap->next = *app;
83 	*app = ap;
84 	aliases++;
85 	INTON;
86 }
87 
88 static int
89 unalias(const char *name)
90 {
91 	struct alias *ap, **app;
92 
93 	app = hashalias(name);
94 
95 	for (ap = *app; ap; app = &(ap->next), ap = ap->next) {
96 		if (equal(name, ap->name)) {
97 			/*
98 			 * if the alias is currently in use (i.e. its
99 			 * buffer is being used by the input routine) we
100 			 * just null out the name instead of freeing it.
101 			 * We could clear it out later, but this situation
102 			 * is so rare that it hardly seems worth it.
103 			 */
104 			if (ap->flag & ALIASINUSE)
105 				*ap->name = '\0';
106 			else {
107 				INTOFF;
108 				*app = ap->next;
109 				ckfree(ap->name);
110 				ckfree(ap->val);
111 				ckfree(ap);
112 				INTON;
113 			}
114 			aliases--;
115 			return (0);
116 		}
117 	}
118 
119 	return (1);
120 }
121 
122 static void
123 rmaliases(void)
124 {
125 	struct alias *ap, *tmp;
126 	int i;
127 
128 	INTOFF;
129 	for (i = 0; i < ATABSIZE; i++) {
130 		ap = atab[i];
131 		atab[i] = NULL;
132 		while (ap) {
133 			ckfree(ap->name);
134 			ckfree(ap->val);
135 			tmp = ap;
136 			ap = ap->next;
137 			ckfree(tmp);
138 		}
139 	}
140 	aliases = 0;
141 	INTON;
142 }
143 
144 struct alias *
145 lookupalias(const char *name, int check)
146 {
147 	struct alias *ap;
148 
149 	if (aliases == 0)
150 		return (NULL);
151 	for (ap = *hashalias(name); ap; ap = ap->next) {
152 		if (equal(name, ap->name)) {
153 			if (check && (ap->flag & ALIASINUSE))
154 				return (NULL);
155 			return (ap);
156 		}
157 	}
158 
159 	return (NULL);
160 }
161 
162 static int
163 comparealiases(const void *p1, const void *p2)
164 {
165 	const struct alias *const *a1 = p1;
166 	const struct alias *const *a2 = p2;
167 
168 	return strcmp((*a1)->name, (*a2)->name);
169 }
170 
171 static void
172 printalias(const struct alias *a)
173 {
174 	out1fmt("%s=", a->name);
175 	out1qstr(a->val);
176 	out1c('\n');
177 }
178 
179 static void
180 printaliases(void)
181 {
182 	int i, j;
183 	struct alias **sorted, *ap;
184 
185 	INTOFF;
186 	sorted = ckmalloc(aliases * sizeof(*sorted));
187 	j = 0;
188 	for (i = 0; i < ATABSIZE; i++)
189 		for (ap = atab[i]; ap; ap = ap->next)
190 			if (*ap->name != '\0')
191 				sorted[j++] = ap;
192 	qsort(sorted, aliases, sizeof(*sorted), comparealiases);
193 	for (i = 0; i < aliases; i++) {
194 		printalias(sorted[i]);
195 		if (int_pending())
196 			break;
197 	}
198 	ckfree(sorted);
199 	INTON;
200 }
201 
202 int
203 aliascmd(int argc __unused, char **argv __unused)
204 {
205 	char *n, *v;
206 	int ret = 0;
207 	struct alias *ap;
208 
209 	nextopt("");
210 
211 	if (*argptr == NULL) {
212 		printaliases();
213 		return (0);
214 	}
215 	while ((n = *argptr++) != NULL) {
216 		if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */
217 			if ((ap = lookupalias(n, 0)) == NULL) {
218 				warning("%s: not found", n);
219 				ret = 1;
220 			} else
221 				printalias(ap);
222 		else {
223 			*v++ = '\0';
224 			setalias(n, v);
225 		}
226 	}
227 
228 	return (ret);
229 }
230 
231 int
232 unaliascmd(int argc __unused, char **argv __unused)
233 {
234 	int i;
235 
236 	while ((i = nextopt("a")) != '\0') {
237 		if (i == 'a') {
238 			rmaliases();
239 			return (0);
240 		}
241 	}
242 	for (i = 0; *argptr; argptr++)
243 		i |= unalias(*argptr);
244 
245 	return (i);
246 }
247 
248 static struct alias **
249 hashalias(const char *p)
250 {
251 	unsigned int hashval;
252 
253 	hashval = (unsigned char)*p << 4;
254 	while (*p)
255 		hashval+= *p++;
256 	return &atab[hashval % ATABSIZE];
257 }
258