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
|
#include "rc.h"
// -----------------------------------------------------------------------
// internal
static char**
mkargv(Word *args)
{
char **argv=emalloc((count(args)+2)*sizeof(char *));
char **argp=argv+1; /* leave one at front for executable */
for(; args; args=args->link)
*argp++=args->str;
*argp=nil;
return argv;
}
static
Word*
envval(char *s)
{
Word *v;
char *t, c;
for(t=s; *t && *t!='\1'; t++)
;
c = *t;
*t = '\0';
v = makeword(s, (c=='\0') ? nil : envval(t+1));
*t=c;
return v;
}
// -----------------------------------------------------------------------
// exported
void
initenv(void)
{
extern char **environ;
char *s;
char **env;
for(env=environ; *env; env++) {
for(s=*env; *s && *s != '(' && *s != '='; s++)
;
switch(*s){
case '\0':
break;
case '(': /* ignore functions */
break;
case '=':
*s = '\0';
setvar(*env, envval(s+1));
*s = '=';
break;
}
}
}
void
execute(Word *cmd, Word *path)
{
int nc;
char **argv = mkargv(cmd);
char **env = mkenv();
char file[1024];
for(; path; path=path->link){
nc = strlen(path->str);
if(nc < arrlen(file)){
strcpy(file, path->str);
if(file[0]){
strcat(file, "/");
nc++;
}
if(nc+strlen(argv[1]) < arrlen(file)){
strcat(file, argv[1]);
execve(file, argv+1, env);
}else
fatal("command name too long");
}
}
print(shell.err, "could not execute command: %s\n", argv[1]);
efree(argv);
}
void
redirect(Redir *r)
{
if(!r) return;
redirect(r->link);
switch(r->type){
case Ropen:
if(r->from != r->to){
dup2(r->from, r->to);
close(r->from);
}
break;
case Rdup:
dup2(r->from, r->to); // TODO: error checking
break;
case Rclose:
close(r->from);
break;
default:
fatal("unrecognized redirection type %d\n", r->type);
}
}
int
mapfd(int fd)
{
Redir *r;
for(r = runner->redir.end; r; r = r->link){
switch(r->type){
case Rclose:
if(r->from == fd)
fd = -1;
break;
case Rdupfd:
case Ropen:
if(r->to == fd)
fd = r->from;
break;
}
}
return fd;
}
|