redirect_heredoc.c

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/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   redirect_heredoc.c                                 :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: rocky <marvin@42.fr>                       +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/09/06 13:46:24 by rocky             #+#    #+#             */
/*   Updated: 2024/09/09 13:50:24 by dmdemirk         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */
 
#include "shell.h"
#include "tokens.h"
#include "redirection.h"
#include "execute.h"
#include <fcntl.h>
#include <sys/wait.h>
#include "signals.h"
 
/*
   GLOBAL VAR
   volatile tells compiler the var can change at compilation between accesses.
   sig_atomic_t used for global_vars
 */
 
volatile sig_atomic_t   g_heredoc_interrupted = 0;
 
static void setup_sigint_handler(struct sigaction *sa_old);
static int  handle_heredoc_interruption(char *line, char *eof, int file_fd, \
        struct sigaction *sa_old);
static void execute_child(t_ast *node, t_ms_data *data, int *file_fd);
static void write_heredoc_lines(char **line, int file_fd, char *eof, \
        t_ms_data *data);
int         redirect_here_doc(t_ast *node, t_ms_data *data);
 
static void setup_sigint_handler(struct sigaction *sa_old)
{
    struct sigaction    sa_new;
 
    sa_new.sa_handler = handle_sigint_heredoc;
    sigemptyset(&sa_new.sa_mask);
    sa_new.sa_flags = 0;
    sigaction(SIGINT, &sa_new, sa_old);
}
 
static int  handle_heredoc_interruption(char *line, char *eof, int file_fd, \
        struct sigaction *sa_old)
{
    free(line);
    free(eof);
    close(file_fd);
    unlink("/tmp/heredoc");
    g_heredoc_interrupted = 0;
    sigaction(SIGINT, sa_old, NULL);
    return (EXIT_FAILURE);
}
 
static void execute_child(t_ast *node, t_ms_data *data, int *file_fd)
{
    pid_t   pid;
 
    pid = fork();
    if (pid == -1)
        ft_perror("fork");
    if (pid == 0)
    {
        data->std_in = dup(*file_fd);
        execute_ast(node, data);
        exit(0);
    }
    close(*file_fd);
    waitpid(pid, &data->exit_status, 0);
}
 
void    write_heredoc_lines(char **line, int file_fd, char *eof, \
            t_ms_data *data)
{
    while (*line && (ft_strcmp(*line, eof) != 0) && !g_heredoc_interrupted)
    {
        write(file_fd, *line, ft_strlen(*line));
        write(file_fd, "\n", 1);
        free(*line);
        (void)data;
        *line = readline("🌞 > ");
    }
}
 
int redirect_here_doc(t_ast *node, t_ms_data *data)
{
    char                *line;
    char                *eof;
    int                 file_fd;
    struct sigaction    sa_old;
 
    line = NULL;
    if (node->right->args[0] == NULL)
        return (1);
    setup_sigint_handler(&sa_old);
    file_fd = open_tmp_file("w");
    eof = ft_strdup(node->right->args[0]);
    line = process_and_reassemble(readline("🌞 > "), data);
    write_heredoc_lines(&line, file_fd, eof, data);
    if (g_heredoc_interrupted)
        return (handle_heredoc_interruption(line, eof, file_fd, &sa_old));
    free(line);
    free(eof);
    close(file_fd);
    sigaction(SIGINT, &sa_old, NULL);
    file_fd = open_tmp_file("r");
    execute_child(node->left, data, &file_fd);
    unlink("/tmp/heredoc");
    return (EXIT_SUCCESS);
}