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
|
#include "eval.h"
#include <string>
#include "error.h"
#include "lang_analysis/lexer_class.h"
#include "lang_analysis/ast.h"
#include "lang_analysis/token.h"
#include "lang_analysis/enum_type.h"
#include "lang_analysis/symbol_property.h"
#include "lang_analysis/parseline.h"
#include "util/io.h"
using namespace std;
extern char **environ;
namespace ov4
{
int eval_exe(const string &s, bool is_async)
{
return eval_exe(s, is_async, nullptr, string::npos);
}
/*
* receive a single command, and execute
*/
int eval_exe(const string &s, bool is_async, const T_lexer *lexer_instance, size_t i, const T_pipe &pi)
{
loggerln("eval_exe: receive {}", s);
bool task_type_is_subshell = false;
const char *raw_input = nullptr;
char **argv = nullptr;
const char *unified_cmd_c = nullptr;
string unified_cmd, s_wrap_eliminated;
// subshell type
if (lexer_instance != nullptr)
{
task_type_is_subshell = true;
unified_cmd = "SUBSHELL";
raw_input = unified_cmd.c_str();
}
// command type
else
{
task_type_is_subshell = false;
s_wrap_eliminated = s.substr(0, s.find('\n')); // eliminate \n
raw_input = s_wrap_eliminated.c_str();
// NB: remember to delete
argv = parseline(s);
if (argv == nullptr || argv[0] == nullptr) { operator delete(argv); return 0; }
if (exe_bultin_command(argv)) { operator delete(argv); return 0; }
unified_cmd = find_cmd(argv[0]);
unified_cmd_c = unified_cmd.c_str();
}
// block_io signals can stop shell
// when child is at foreground, parent shell is at background
sigprocmask(SIG_BLOCK, &block_io, nullptr);
sigset_t prev;
block_all(&prev);
shell_pgid = getpgid(0);
pid_t pid = fork();
if (pid == 0) // child
{
setpgid(0, 0);
if (!is_async) // foreground
tcsetpgrp(tty_fd, getpgrp());
sigprocmask(SIG_SETMASK, &prev, nullptr);
// program inside execve may use SIGTTIN/SIGTTOU
// so just restore in child
sigprocmask(SIG_UNBLOCK, &block_io, nullptr);
// subshell
if (task_type_is_subshell)
{
eval_tree_cd(i, *lexer_instance, true);
exit(0);
}
// normal command
execve(unified_cmd_c, argv, environ);
// execve: if success, never returns
cout << raw_input << flush;
eval_err(errno);
}
// parent
operator delete(argv);
argv = nullptr;
exit_required_pid = pid;
if (!is_async) // foreground
{
addjob(pid, FG, raw_input);
sigset_t prev_with_sigchld_blocked = prev;
sigaddset(&prev_with_sigchld_blocked, SIGCHLD);
sigprocmask(SIG_SETMASK, &prev_with_sigchld_blocked, NULL);
waitfg(pid);
sigprocmask(SIG_SETMASK, &prev, NULL);
return exit_code;
}
else // background
{
addjob(pid, BG, raw_input);
sigprocmask(SIG_SETMASK, &prev, NULL);
cout << "[" << pid2jid(pid) << "] (" << pid << ") " << raw_input;
// POSIX:
// async command returns 0 immediately
// TODO: recurring async
return 0;
}
return 0;
}
}
|
