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
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
/* ************************************************************************** */
/* */
/* ::: :::::::: */
/* eval.c :+: :+: :+: */
/* +:+ +:+ +:+ */
/* By: charles <charles.cabergs@gmail.com> +#+ +:+ +#+ */
/* +#+#+#+#+#+ +#+ */
/* Created: 2020/04/01 17:05:21 by charles #+# #+# */
/* Updated: 2020/05/04 12:00:38 by charles ### ########.fr */
/* */
/* ************************************************************************** */
/*
** \file eval.c
** \brief Evaluation of an AST
*/
#include "eval.h"
/*
** \brief Wrap a function in a fork
** \param fd_in fork input file descriptor
** \param fd_out fork output file descriptor
** \param passed param of the wrapped function
** \param wrapped function to wrap
*/
int fork_wrap(
int fd_in,
int fd_out,
void *passed,
int (*wrapped)(void *param))
{
int status;
pid_t child_pid;
if ((child_pid = fork()) == -1)
return (-1);
if (child_pid == 0)
{
if (dup2(STDIN_FILENO, fd_in) == -1 ||
dup2(STDOUT_FILENO, fd_out) == -1)
exit(EXIT_FAILURE);
if ((status = wrapped(passed)) == -1)
exit(EXIT_FAILURE);
exit(status);
}
wait(&child_pid);
return (WEXITSTATUS(child_pid));
}
int run_builtin(t_eval_state *state, char **argv)
{
return (builtin_dispatch_run(argv, state->env));
}
/*
** \brief execve syscall wrapper passed it to fork_wrap
** \param param function params
** \return execve return value
*/
int execve_wrapper(void *param)
{
return (execve(
((t_fork_param_execve*)param)->exec_path,
((t_fork_param_execve*)param)->argv,
((t_fork_param_execve*)param)->envp
));
}
/*
** \brief Evaluate a command
** \param state Evaluation state
** \param cmd Command to evaluate
** \return Executable status or -1 on error
*/
static int eval_cmd(int fd_in, int fd_out, t_eval_state *state, t_cmd *cmd)
{
t_fork_param_execve param;
if (builtin_check_exec_name(cmd->argv[0]))
return (run_builtin(state, cmd->argv));
param.exec_path = exec_search_path(
state->path, env_search(state->env, "PATH"), cmd->argv[0]);
if (param.exec_path == NULL)
return (-1);
if (cmd->in != NULL && (fd_in = open(cmd->in, O_RDONLY)) == -1)
return (-1);
if (cmd->out != NULL && (fd_out = open(cmd->out,
(cmd->is_append ? O_APPEND : O_RDONLY) | O_CREAT)) == -1)
return (-1);
param.argv = cmd->argv;
param.envp = (char**)state->env->data;
return (fork_wrap(fd_in, fd_out, ¶m, &execve_wrapper));
}
/*
** \brief Evaluate a line
** \param state State of the evaluation
** \param line Line to evaluate
** \return Last Executed command status or -1 on error
*/
static int eval_line(void *param)
{
int status;
t_eval_state *state;
t_line *line;
int fd_in;
int fd_out;
state = ((t_fork_param_line*)param)->state;
line = ((t_fork_param_line*)param)->line;
fd_in = ((t_fork_param_line*)param)->fd_in;
fd_out = ((t_fork_param_line*)param)->fd_out;
/* if (line->right == NULL) */
/* return (eval(state, line->left)); */
/* if (line->sep == SEP_PIPE) */
/* pipe(state->p); */
if (line->left->tag == TAG_LINE)
{
return (fork_wrap(fd_in, fd_out, param, &eval_line));
}
if ((status = eval(fd_in, fd_out, state, line->left)) == -1)
return (-1);
if ((line->sep == SEP_AND && status != 0) ||
(line->sep == SEP_OR && status == 0))
return (status);
return (eval(fd_in, fd_out, state, line->right));
}
/*
** \brief Evaluate an AST
** \param state State of the evaluation
** \param ast Abstract syntax tree to evaluate
** \return Last command status or -1 on error
*/
int eval(int fd_in, int fd_out, t_eval_state *state, t_ast *ast)
{
t_fork_param_line param;
errno = 0;
if (ast->tag == TAG_LINE)
{
param.state = state;
param.line = &ast->line;
param.fd_in = fd_in;
param.fd_out = fd_out;
return (eval_line(¶m));
}
if (ast->tag == TAG_CMD)
return (eval_cmd(fd_in, fd_out, state, &ast->cmd));
return (-1);
}
|
