1 /* $NetBSD: alias.c,v 1.15 2014/06/18 18:17:30 christos Exp $ */
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35 #include <sys/cdefs.h>
38 static char sccsid
[] = "@(#)alias.c 8.3 (Berkeley) 5/4/95";
40 __RCSID("$NetBSD: alias.c,v 1.15 2014/06/18 18:17:30 christos Exp $");
52 #include "options.h" /* XXX for argptr (should remove?) */
58 struct alias
*atab
[ATABSIZE
];
60 STATIC
void setalias(char *, char *);
61 STATIC
int unalias(char *);
62 STATIC
struct alias
**hashalias(const char *);
66 setalias(char *name
, char *val
)
68 struct alias
*ap
, **app
;
70 app
= hashalias(name
);
71 for (ap
= *app
; ap
; ap
= ap
->next
) {
72 if (equal(name
, ap
->name
)) {
75 ap
->val
= savestr(val
);
82 ap
= ckmalloc(sizeof (struct alias
));
83 ap
->name
= savestr(name
);
86 * XXX - HACK: in order that the parser will not finish reading the
87 * alias value off the input before processing the next alias, we
88 * dummy up an extra space at the end of the alias. This is a crock
89 * and should be re-thought. The idea (if you feel inclined to help)
90 * is to avoid alias recursions. The mechanism used is: when
91 * expanding an alias, the value of the alias is pushed back on the
92 * input as a string and a pointer to the alias is stored with the
93 * string. The alias is marked as being in use. When the input
94 * routine finishes reading the string, it markes the alias not
95 * in use. The problem is synchronization with the parser. Since
96 * it reads ahead, the alias is marked not in use before the
97 * resulting token(s) is next checked for further alias sub. The
98 * H A C K is that we add a little fluff after the alias value
99 * so that the string will not be exhausted. This is a good
100 * idea ------- ***NOT***
103 ap
->val
= savestr(val
);
106 int len
= strlen(val
);
107 ap
->val
= ckmalloc(len
+ 2);
108 memcpy(ap
->val
, val
, len
);
109 ap
->val
[len
] = ' '; /* fluff */
110 ap
->val
[len
+1] = '\0';
121 struct alias
*ap
, **app
;
123 app
= hashalias(name
);
125 for (ap
= *app
; ap
; app
= &(ap
->next
), ap
= ap
->next
) {
126 if (equal(name
, ap
->name
)) {
128 * if the alias is currently in use (i.e. its
129 * buffer is being used by the input routine) we
130 * just null out the name instead of freeing it.
131 * We could clear it out later, but this situation
132 * is so rare that it hardly seems worth it.
134 if (ap
->flag
& ALIASINUSE
)
152 MKINIT
void rmaliases(void);
162 struct alias
*ap
, *tmp
;
166 for (i
= 0; i
< ATABSIZE
; i
++) {
181 lookupalias(const char *name
, int check
)
183 struct alias
*ap
= *hashalias(name
);
185 for (; ap
; ap
= ap
->next
) {
186 if (equal(name
, ap
->name
)) {
187 if (check
&& (ap
->flag
& ALIASINUSE
))
197 alias_text(void *dummy __unused
, const char *name
)
201 ap
= lookupalias(name
, 0);
211 aliascmd(int argc
, char **argv
)
220 for (i
= 0; i
< ATABSIZE
; i
++)
221 for (ap
= atab
[i
]; ap
; ap
= ap
->next
) {
222 if (*ap
->name
!= '\0') {
223 out1fmt("alias %s=", ap
->name
);
224 print_quoted(ap
->val
);
230 while ((n
= *++argv
) != NULL
) {
231 if ((v
= strchr(n
+1, '=')) == NULL
) { /* n+1: funny ksh stuff */
232 if ((ap
= lookupalias(n
, 0)) == NULL
) {
233 outfmt(out2
, "alias: %s not found\n", n
);
236 out1fmt("alias %s=", n
);
237 print_quoted(ap
->val
);
250 unaliascmd(int argc
, char **argv
)
254 while ((i
= nextopt("a")) != '\0') {
260 for (i
= 0; *argptr
; argptr
++)
261 i
= unalias(*argptr
);
266 STATIC
struct alias
**
267 hashalias(const char *p
)
269 unsigned int hashval
;
274 return &atab
[hashval
% ATABSIZE
];