summaryrefslogtreecommitdiffstats
path: root/bin/sh/alias.c
blob: 3cf38a93f2396231a82db00c0c4634fc674086b8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
/*-
 * Copyright (c) 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)alias.c	8.1 (Berkeley) 5/31/93";
#endif /* not lint */

#include "shell.h"
#include "input.h"
#include "output.h"
#include "error.h"
#include "memalloc.h"
#include "mystring.h"
#include "alias.h"
#include "options.h"	/* XXX for argptr (should remove?) */

#define ATABSIZE 39

struct alias *atab[ATABSIZE];

STATIC struct alias **hashalias __P((char *));

STATIC
setalias(name, val)
	char *name, *val;
	{
	struct alias *ap, **app;

	app = hashalias(name);
	for (ap = *app; ap; ap = ap->next) {
		if (equal(name, ap->name)) {
			INTOFF;
			ckfree(ap->val);
			ap->val	= savestr(val);
			INTON;
			return;
		}
	}
	/* not found */
	INTOFF;
	ap = ckmalloc(sizeof (struct alias));
	ap->name = savestr(name);
	/*
	 * XXX - HACK: in order that the parser will not finish reading the
	 * alias value off the input before processing the next alias, we
	 * dummy up an extra space at the end of the alias.  This is a crock
	 * and should be re-thought.  The idea (if you feel inclined to help)
	 * is to avoid alias recursions.  The mechanism used is: when
	 * expanding an alias, the value of the alias is pushed back on the
	 * input as a string and a pointer to the alias is stored with the
	 * string.  The alias is marked as being in use.  When the input
	 * routine finishes reading the string, it markes the alias not
	 * in use.  The problem is synchronization with the parser.  Since
	 * it reads ahead, the alias is marked not in use before the
	 * resulting token(s) is next checked for further alias sub.  The
	 * H A C K is that we add a little fluff after the alias value
	 * so that the string will not be exhausted.  This is a good
	 * idea ------- ***NOT***
	 */
#ifdef notyet
	ap->val = savestr(val);
#else /* hack */
	{
	int len = strlen(val);
	ap->val = ckmalloc(len + 2);
	bcopy(val, ap->val, len);
	ap->val[len] = ' ';	/* fluff */
	ap->val[len+1] = '\0';
	}
#endif
	ap->next = *app;
	*app = ap;
	INTON;
}

STATIC int
unalias(name)
	char *name;
	{
	struct alias *ap, **app;

	app = hashalias(name);

	for (ap = *app; ap; app = &(ap->next), ap = ap->next) {
		if (equal(name, ap->name)) {
			/*
			 * if the alias is currently in use (i.e. its
			 * buffer is being used by the input routine) we
			 * just null out the name instead of freeing it.
			 * We could clear it out later, but this situation
			 * is so rare that it hardly seems worth it.
			 */
			if (ap->flag & ALIASINUSE)
				*ap->name = '\0';
			else {
				INTOFF;
				*app = ap->next;
				ckfree(ap->name);
				ckfree(ap->val);
				ckfree(ap);
				INTON;
			}
			return (0);
		}
	}

	return (1);
}

#ifdef mkinit
MKINIT void rmaliases();

SHELLPROC {
	rmaliases();
}
#endif

void
rmaliases() {
	struct alias *ap, *tmp;
	int i;

	INTOFF;
	for (i = 0; i < ATABSIZE; i++) {
		ap = atab[i];
		atab[i] = NULL;
		while (ap) {
			ckfree(ap->name);
			ckfree(ap->val);
			tmp = ap;
			ap = ap->next;
			ckfree(tmp);
		}
	}
	INTON;
}

struct alias *
lookupalias(name, check)
	char *name;
	{
	struct alias *ap = *hashalias(name);

	for (; ap; ap = ap->next) {
		if (equal(name, ap->name)) {
			if (check && (ap->flag & ALIASINUSE))
				return (NULL);
			return (ap);
		}
	}

	return (NULL);
}

/*
 * TODO - sort output
 */
aliascmd(argc, argv)
	char **argv;
	{
	char *n, *v;
	int ret = 0;
	struct alias *ap;

	if (argc == 1) {
		int i;

		for (i = 0; i < ATABSIZE; i++)
			for (ap = atab[i]; ap; ap = ap->next) {
				if (*ap->name != '\0')
				    out1fmt("alias %s=%s\n", ap->name, ap->val);
			}
		return (0);
	}
	while (n = *++argv) {
		if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */
			if ((ap = lookupalias(n, 0)) == NULL) {
				outfmt(out2, "alias: %s not found\n", n);
				ret = 1;
			} else
				out1fmt("alias %s=%s\n", n, ap->val);
		else {
			*v++ = '\0';
			setalias(n, v);
		}
	}

	return (ret);
}

unaliascmd(argc, argv)
	char **argv;
	{
	int i;
	
	while ((i = nextopt("a")) != '\0') {
		if (i == 'a') {
			rmaliases();
			return (0);
		}
	}
	for (i = 0; *argptr; argptr++)
		i = unalias(*argptr);

	return (i);
}

STATIC struct alias **
hashalias(p)
	register char *p;
	{
	unsigned int hashval;

	hashval = *p << 4;
	while (*p)
		hashval+= *p++;
	return &atab[hashval % ATABSIZE];
}
OpenPOWER on IntegriCloud