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
|
#include "builtins.h"
#include "shell.h"
#include <camellia/syscalls.h>
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
int main();
static void execp(char **argv) {
if (!argv || !*argv) return;
if (argv[0][0] == '/') {
execv(argv[0], argv);
return;
}
size_t cmdlen = strlen(argv[0]);
char *s = malloc(cmdlen);
if (!s) {
eprintf("out of memory.");
exit(1);
}
memcpy(s, "/bin/", 5);
memcpy(s + 5, argv[0], cmdlen + 1);
argv[0] = s;
execv(s, argv);
free(s);
}
static void run(char *cmd) {
#define ARGV_MAX 16
char *argv[ARGV_MAX];
struct redir redir;
int argc = parse(cmd, argv, ARGV_MAX, &redir);
if (argc < 0) {
eprintf("error parsing command");
return;
}
if (!*argv) return;
/* "special" commands that can't be handled in a subprocess */
if (!strcmp(argv[0], "shadow")) {
// TODO process groups
_syscall_mount(-1, argv[1], strlen(argv[1]));
return;
} else if (!strcmp(argv[0], "exit")) {
exit(0);
}
if (fork()) {
_syscall_await();
return;
}
if (redir.stdout && !freopen(redir.stdout, redir.append ? "a" : "w", stdout)) {
eprintf("couldn't open %s for redirection", redir.stdout);
exit(0);
}
for (struct builtin *iter = builtins; iter->name; iter++) {
if (!strcmp(argv[0], iter->name)) {
iter->fn(argc, argv);
exit(0);
}
}
execp(argv);
if (errno == EINVAL) {
eprintf("%s isn't a valid executable\n", argv[0]);
} else {
eprintf("unknown command: %s\n", argv[0]);
}
exit(0); /* kills the subprocess */
}
int main(int argc, char **argv) {
static char buf[256];
FILE *f = stdin;
if (argc > 1) {
f = fopen(argv[1], "r");
if (!f) {
eprintf("couldn't open %s\n", argv[1]);
return 1;
}
}
for (;;) {
if (f == stdin)
printf("$ ");
if (!fgets(buf, 256, f))
return 0;
run(buf);
}
}
|
