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/* ************************************************************************** */
/* */
/* ::: :::::::: */
/* eval.c :+: :+: :+: */
/* +:+ +:+ +:+ */
/* By: charles <charles.cabergs@gmail.com> +#+ +:+ +#+ */
/* +#+#+#+#+#+ +#+ */
/* Created: 2020/04/01 17:05:21 by charles #+# #+# */
/* Updated: 2020/04/02 17:08:18 by charles ### ########.fr */
/* */
/* ************************************************************************** */
/*
** \file eval.c
** \brief Evaluation of an AST
*/
#include "eval.h"
#define PARAM_SIZE 3
#define PARAM_STATE 0
#define PARAM_LINE 1
#define PARAM_EXEC_PATH 0
#define PARAM_ARGV 1
#define PARAM_ENVP 2
int io_frame_init(t_io_frame *frame)
{
if (pipe(frame->pipe_in) == -1
|| pipe(frame->pipe_out) == -1)
return (-1);
/* frame->pipe_in[PIPE_READ] = STDIN_FILENO; */
/* frame->pipe_in[PIPE_WRITE] = PIPE_CLOSED; */
/* frame->pipe_out[PIPE_READ] = PIPE_CLOSED; */
/* frame->pipe_out[PIPE_WRITE] = STDOUT_FILENO; */
return (0);
}
static int eval_root(void *params[PARAM_SIZE])
{
int status;
t_eval_state *state;
t_line *line;
t_io_frame frame_left;
t_io_frame frame_right;
state = params[PARAM_STATE];
line = params[PARAM_LINE];
io_frame_init(&frame_left);
if (line->right == NULL)
return (eval(&frame_left, state, line->left));
if (line->sep == SEP_PIPE)
dup2(STDOUT_FILENO, frame_left.pipe_out[PIPE_WRITE]);
if ((status = eval(&frame_left, state, line->left)) == -1)
return (-1);
if ((line->sep == SEP_AND && status != 0) ||
(line->sep == SEP_OR && status == 0))
return (status);
if (line->sep == SEP_PIPE)
dup2(frame_right.pipe_in[PIPE_WRITE], frame_left.pipe_out[PIPE_READ]);
return (eval(&frame_right, state, line->right));
}
int execve_wrapper(void *params[PARAM_SIZE])
{
return (execve(
params[PARAM_EXEC_PATH],
params[PARAM_ARGV],
params[PARAM_ENVP]
));
}
int exec_wrap(
t_io_frame *frame,
void *passed[PARAM_SIZE],
int (*wrapped)(void *params[PARAM_SIZE])
)
{
int status;
pid_t child_pid;
if ((child_pid = fork()) == -1)
return (-1);
if (child_pid == 0)
{
if (dup2(STDIN_FILENO, frame->pipe_in[PIPE_READ]) == -1 ||
dup2(STDOUT_FILENO, frame->pipe_out[PIPE_WRITE]) == -1)
exit(EXIT_FAILURE);
if ((status = wrapped(passed)) == -1)
exit(EXIT_FAILURE);
exit(status);
}
wait(&child_pid);
return (WEXITSTATUS(child_pid));
}
/*
** \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(t_io_frame *frame, t_eval_state *state, t_line *line)
{
void *params[PARAM_SIZE];
params[PARAM_STATE] = state;
params[PARAM_LINE] = line;
return (exec_wrap(frame, params, &eval_root));
}
int run_builtin(t_eval_state *state, char **argv)
{
return (builtin_dispatch_run(argv, state->env));
}
/*
** \brief Evaluate a command
** \param state Evaluation state
** \param cmd Command to evaluate
** \return Executable status or -1 on error
*/
static int eval_cmd(t_io_frame *frame, t_eval_state *state, t_cmd *cmd)
{
void *params[PARAM_SIZE];
if (builtin_check_exec_name(cmd->argv[0]))
return (run_builtin(state, cmd->argv));
params[PARAM_EXEC_PATH] = exec_search_path(
state->path, env_search(state->env, "PATH"), cmd->argv[0]);
if (params[PARAM_EXEC_PATH] == NULL)
return (-1);
if (cmd->in != NULL)
if ((frame->pipe_in[PIPE_WRITE] = open(cmd->in, O_RDONLY)) == -1)
return (-1);
if (cmd->out != NULL)
if ((frame->pipe_out[PIPE_READ] = open(cmd->out,
(cmd->is_append ? O_APPEND : O_RDONLY) | O_CREAT)) == -1)
return (-1);
params[PARAM_ARGV] = cmd->argv;
params[PARAM_ENVP] = state->env->data;
return (exec_wrap(frame, params, &execve_wrapper));
}
/*
** \brief Evaluate an AST
** \param state State of the evaluation
** \param ast Abstract syntax tree to evaluate
** \return Executable status or -1 on error
*/
int eval(t_io_frame *frame, t_eval_state *state, t_ast *ast)
{
void *params[PARAM_SIZE];
errno = 0;
if (ast->tag == TAG_ROOT)
{
params[PARAM_STATE] = state;
params[PARAM_LINE] = &ast->data.line;
return (eval_root(params));
}
if (ast->tag == TAG_LINE)
return (eval_line(frame, state, &ast->data.line));
if (ast->tag == TAG_CMD)
return (eval_cmd(frame, state, &ast->data.cmd));
return (-1);
}
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