1 #include "rc.h"
2 #include "exec.h"
3 #include "fns.h"
4 
5 int
6 hash(char *s, int n)
7 {
8 	int h = 0, i = 1;
9 	while(*s) h+=*s++*i++;
10 	h%=n;
11 	return h<0?h+n:h;
12 }
13 #define	NKW	30
14 struct kw{
15 	char *name;
16 	int type;
17 	struct kw *next;
18 }*kw[NKW];
19 
20 void
21 kenter(int type, char *name)
22 {
23 	int h = hash(name, NKW);
24 	struct kw *p = new(struct kw);
25 	p->type = type;
26 	p->name = name;
27 	p->next = kw[h];
28 	kw[h] = p;
29 }
30 
31 void
32 kinit(void)
33 {
34 	kenter(FOR, "for");
35 	kenter(IN, "in");
36 	kenter(WHILE, "while");
37 	kenter(IF, "if");
38 	kenter(NOT, "not");
39 	kenter(TWIDDLE, "~");
40 	kenter(BANG, "!");
41 	kenter(SUBSHELL, "@");
42 	kenter(SWITCH, "switch");
43 	kenter(FN, "fn");
44 }
45 
46 tree*
47 klook(char *name)
48 {
49 	struct kw *p;
50 	tree *t = token(name, WORD);
51 	for(p = kw[hash(name, NKW)];p;p = p->next)
52 		if(strcmp(p->name, name)==0){
53 			t->type = p->type;
54 			t->iskw = 1;
55 			break;
56 		}
57 	return t;
58 }
59 
60 var*
61 gvlook(char *name)
62 {
63 	int h = hash(name, NVAR);
64 	var *v;
65 	for(v = gvar[h];v;v = v->next) if(strcmp(v->name, name)==0) return v;
66 	return gvar[h] = newvar(strdup(name), gvar[h]);
67 }
68 
69 var*
70 vlook(char *name)
71 {
72 	var *v;
73 	if(runq)
74 		for(v = runq->local;v;v = v->next)
75 			if(strcmp(v->name, name)==0) return v;
76 	return gvlook(name);
77 }
78 
79 void
80 _setvar(char *name, word *val, int callfn)
81 {
82 	struct var *v = vlook(name);
83 	freewords(v->val);
84 	v->val=val;
85 	v->changed=1;
86 	if(callfn && v->changefn)
87 		v->changefn(v);
88 }
89 
90 void
91 setvar(char *name, word *val)
92 {
93 	_setvar(name, val, 1);
94 }
95 
96 void
97 bigpath(var *v)
98 {
99 	/* convert $PATH to $path */
100 	char *p, *q;
101 	word **l, *w;
102 
103 	if(v->val == nil){
104 		_setvar("path", nil, 0);
105 		return;
106 	}
107 	p = v->val->word;
108 	w = nil;
109 	l = &w;
110 	/*
111 	 * Doesn't handle escaped colon nonsense.
112 	 */
113 	if(p[0] == 0)
114 		p = nil;
115 	while(p){
116 		q = strchr(p, ':');
117 		if(q)
118 			*q = 0;
119 		*l = newword(p[0] ? p : ".", nil);
120 		l = &(*l)->next;
121 		if(q){
122 			*q = ':';
123 			p = q+1;
124 		}else
125 			p = nil;
126 	}
127 	_setvar("path", w, 0);
128 }
129 
130 char*
131 list2strcolon(word *words)
132 {
133 	char *value, *s, *t;
134 	int len = 0;
135 	word *ap;
136 	for(ap = words;ap;ap = ap->next)
137 		len+=1+strlen(ap->word);
138 	value = emalloc(len+1);
139 	s = value;
140 	for(ap = words;ap;ap = ap->next){
141 		for(t = ap->word;*t;) *s++=*t++;
142 		*s++=':';
143 	}
144 	if(s==value)
145 		*s='\0';
146 	else s[-1]='\0';
147 	return value;
148 }
149 void
150 littlepath(var *v)
151 {
152 	/* convert $path to $PATH */
153 	char *p;
154 	word *w;
155 
156 	p = list2strcolon(v->val);
157 	w = new(word);
158 	w->word = p;
159 	w->next = nil;
160 	_setvar("PATH", w, 1);	/* 1: recompute $path to expose colon problems */
161 }
162 
163 void
164 pathinit(void)
165 {
166 	var *v;
167 
168 	v = gvlook("path");
169 	v->changefn = littlepath;
170 	v = gvlook("PATH");
171 	v->changefn = bigpath;
172 	bigpath(v);
173 }