cmd_exec_command.c

#include <unistd.h>
#include "execution.h"
#include "minishell.h"
#include "builtin.h"
#include "libft/libft.h"

/*
 * Connect pipe to STDIN_FILENO and STDOUT_FILE_NO.
 *
 * replace STDIN_FILENO and STDOUT_FILE_NO with pipe by dup2().
 */
static void	replace_stdio_with_pipe(t_command_invocation *command,
	int pipe_prev_fd[2], int pipe_fd[2])
{
	if (pipe_prev_fd[1] >= 0)
	{
		close(pipe_prev_fd[1]);
		if (dup2(pipe_prev_fd[0], STDIN_FILENO) == -1)
			put_err_msg_and_exit("error child dup2(in)");
		close(pipe_prev_fd[0]);
	}
	if (command->piped_command)
	{
		close(pipe_fd[0]);
		if (dup2(pipe_fd[1], STDOUT_FILENO) == -1)
			put_err_msg_and_exit("error child dup2(out)");
		close(pipe_fd[1]);
	}
}

/*
 * Execute a command.
 * This function is supposed to be called in child process.
 *
 * command: command
 * pipe_prev_fd[2]: A pipe that connects the previous and current process.
 * pipe_fd[2]: A pipe that connects the current and next process.
 */
void	cmd_exec_command(t_command_invocation *command,
	int pipe_prev_fd[2], int pipe_fd[2], t_fd_reds_list *in_fd_reds_list)
{
	t_builtin_cmd	*builtin_func;

	set_sighandlers(SIG_DFL);
	replace_stdio_with_pipe(command, pipe_prev_fd, pipe_fd);
	if (cmd_set_input_file(in_fd_reds_list) == ERROR
		|| cmd_set_output_file(command) == ERROR)
		exit(EXIT_FAILURE);
	if (!command->exec_and_args)
		exit(0);
	builtin_func = get_builtin_func((char *)command->exec_and_args[0]);
	if (builtin_func)
		exit(builtin_func((char **)command->exec_and_args));
	cmd_execvp((char *)command->exec_and_args[0],
		(char **) command->exec_and_args);
}