xref: /freebsd/bin/sh/alias.c (revision 401ab69cff8fa2320a9f8ea4baa114a6da6c952b)
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 #include <stdlib.h>
40 #include "shell.h"
41 #include "output.h"
42 #include "error.h"
43 #include "memalloc.h"
44 #include "mystring.h"
45 #include "alias.h"
46 #include "options.h"
47 #include "builtins.h"
48 
49 #define ATABSIZE 39
50 
51 static struct alias *atab[ATABSIZE];
52 static int aliases;
53 
54 static void setalias(const char *, const char *);
55 static int unalias(const char *);
56 static struct alias **hashalias(const char *);
57 
58 static
59 void
60 setalias(const char *name, const char *val)
61 {
62 	struct alias *ap, **app;
63 
64 	unalias(name);
65 	app = hashalias(name);
66 	INTOFF;
67 	ap = ckmalloc(sizeof (struct alias));
68 	ap->name = savestr(name);
69 	ap->val = savestr(val);
70 	ap->flag = 0;
71 	ap->next = *app;
72 	*app = ap;
73 	aliases++;
74 	INTON;
75 }
76 
77 static void
78 freealias(struct alias *ap)
79 {
80 	ckfree(ap->name);
81 	ckfree(ap->val);
82 	ckfree(ap);
83 }
84 
85 static int
86 unalias(const char *name)
87 {
88 	struct alias *ap, **app;
89 
90 	app = hashalias(name);
91 
92 	for (ap = *app; ap; app = &(ap->next), ap = ap->next) {
93 		if (equal(name, ap->name)) {
94 			/*
95 			 * if the alias is currently in use (i.e. its
96 			 * buffer is being used by the input routine) we
97 			 * just null out the name instead of freeing it.
98 			 * We could clear it out later, but this situation
99 			 * is so rare that it hardly seems worth it.
100 			 */
101 			if (ap->flag & ALIASINUSE)
102 				*ap->name = '\0';
103 			else {
104 				INTOFF;
105 				*app = ap->next;
106 				freealias(ap);
107 				INTON;
108 			}
109 			aliases--;
110 			return (0);
111 		}
112 	}
113 
114 	return (1);
115 }
116 
117 static void
118 rmaliases(void)
119 {
120 	struct alias *ap, **app;
121 	int i;
122 
123 	INTOFF;
124 	for (i = 0; i < ATABSIZE; i++) {
125 		app = &atab[i];
126 		while (*app) {
127 			ap = *app;
128 			if (ap->flag & ALIASINUSE) {
129 				*ap->name = '\0';
130 				app = &(*app)->next;
131 			} else {
132 				*app = ap->next;
133 				freealias(ap);
134 			}
135 		}
136 	}
137 	aliases = 0;
138 	INTON;
139 }
140 
141 struct alias *
142 lookupalias(const char *name, int check)
143 {
144 	struct alias *ap;
145 
146 	if (aliases == 0)
147 		return (NULL);
148 	for (ap = *hashalias(name); ap; ap = ap->next) {
149 		if (equal(name, ap->name)) {
150 			if (check && (ap->flag & ALIASINUSE))
151 				return (NULL);
152 			return (ap);
153 		}
154 	}
155 
156 	return (NULL);
157 }
158 
159 static int
160 comparealiases(const void *p1, const void *p2)
161 {
162 	const struct alias *const *a1 = p1;
163 	const struct alias *const *a2 = p2;
164 
165 	return strcmp((*a1)->name, (*a2)->name);
166 }
167 
168 static void
169 printalias(const struct alias *a)
170 {
171 	out1fmt("%s=", a->name);
172 	out1qstr(a->val);
173 	out1c('\n');
174 }
175 
176 static void
177 printaliases(void)
178 {
179 	int i, j;
180 	struct alias **sorted, *ap;
181 
182 	INTOFF;
183 	sorted = ckmalloc(aliases * sizeof(*sorted));
184 	j = 0;
185 	for (i = 0; i < ATABSIZE; i++)
186 		for (ap = atab[i]; ap; ap = ap->next)
187 			if (*ap->name != '\0')
188 				sorted[j++] = ap;
189 	qsort(sorted, aliases, sizeof(*sorted), comparealiases);
190 	for (i = 0; i < aliases; i++) {
191 		printalias(sorted[i]);
192 		if (int_pending())
193 			break;
194 	}
195 	ckfree(sorted);
196 	INTON;
197 }
198 
199 int
200 aliascmd(int argc __unused, char **argv __unused)
201 {
202 	char *n, *v;
203 	int ret = 0;
204 	struct alias *ap;
205 
206 	nextopt("");
207 
208 	if (*argptr == NULL) {
209 		printaliases();
210 		return (0);
211 	}
212 	while ((n = *argptr++) != NULL) {
213 		if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */
214 			if ((ap = lookupalias(n, 0)) == NULL) {
215 				warning("%s: not found", n);
216 				ret = 1;
217 			} else
218 				printalias(ap);
219 		else {
220 			*v++ = '\0';
221 			setalias(n, v);
222 		}
223 	}
224 
225 	return (ret);
226 }
227 
228 int
229 unaliascmd(int argc __unused, char **argv __unused)
230 {
231 	int i;
232 
233 	while ((i = nextopt("a")) != '\0') {
234 		if (i == 'a') {
235 			rmaliases();
236 			return (0);
237 		}
238 	}
239 	for (i = 0; *argptr; argptr++)
240 		i |= unalias(*argptr);
241 
242 	return (i);
243 }
244 
245 static struct alias **
246 hashalias(const char *p)
247 {
248 	unsigned int hashval;
249 
250 	hashval = (unsigned char)*p << 4;
251 	while (*p)
252 		hashval+= *p++;
253 	return &atab[hashval % ATABSIZE];
254 }
255