Question

当我的程序退出时，似乎我的双指针没有被释放。我正在使用以下功能创建environ的副本。

char    **envp_cpy(char **envp)
{
    char    **copy;
    int     i;

    i = 0;
    copy = (char **)malloc((ft_array_len(envp) + 1) * sizeof(char *));
    copy[ft_array_len(envp)] = NULL;
    if (copy)
    {
        while (envp[i])
        {
            //valgrind complains about this line (74 in my file)
            copy[i] = ft_strdup(envp[i]);
            i++;
        }
    }
    return (copy);
}

我使用setenv为复制的environ

添加值

int     ft_setenv(const char *name, const char *val, int ovride, char **envp)
{
    char    *es;
    int     i;

    if (name == NULL || name[0] == '\0' || ft_strchr(name, '=') != NULL ||
        val == NULL)
    {
        return (-1);
    }
    if (ft_get_env(name, envp) != NULL && ovride == 0)
        return (0);
    ft_unsetenv(name, envp);
    es = ft_memalloc(ft_strlen(name) + ft_strlen(val) + 2);
    if (es == NULL)
        return (-1);
    ft_strcpy(es, name);
    ft_strcat(es, "=");
    ft_strcat(es, val);
    i = (ft_add_value(es, envp) != 0) ? -1 : 0;
    free(es);
    return (i);
}

将值添加到environ

的功能

int     ft_add_value(char *str, char **envp)
{
    int     i;

    i = 0;
    while (envp[i])
    {
        i++;
    }
    if ((envp[i] = ft_strdup(str))) //valgrind complains about this line
    {
         envp[++i] = 0;
        return (1);
    }
    return (0);
}

我使用此功能释放副本

void    freecopy(char **copy)
{
    int i;

    i = 0;
    while (copy[i])
    {
        free(copy[i]);
        i++;
    }
    free(copy);
}

我在退出

之前释放了这个函数内的副本

void    ft_process_cmd(t_cmd *cmd, char **env, struct termios *t, t_stack *hist)
{
    if (cmd->user_comm != NULL)
    {
        if (ft_strequ(cmd->user_comm[0], "exit"))
        {
            free_stack(hist);
            freecopy(env); //I free the copy here
            free_cmd(cmd);
            ft_close_keyboard(t);
            exit(0);
        }
        hist->size = hist->hist_count;
        ft_push(hist, cmd->get_line);
        ft_run_commands(cmd->user_comm, cmd->get_line, env, *hist);
    }
}

Valgrind结果

==7699== HEAP SUMMARY:
==7699==     in use at exit: 15,511 bytes in 26 blocks
==7699==   total heap usage: 1,404 allocs, 1,391 frees, 120,569 bytes allocated
==7699== 
==7699== 51 bytes in 2 blocks are definitely lost in loss record 8 of 19
==7699==    at 0x4C2DB9D: malloc (vg_replace_malloc.c:299)
==7699==    by 0x403C81: ft_memalloc (in /home/julekgwa/21shell/21sh)
==7699==    by 0x4039E9: ft_strdup (in /home/julekgwa/21shell/21sh)
==7699==    by 0x4015EE: envp_cpy (ft_ctrl_c_signal_handler.c:74)
==7699==    by 0x401050: main (main.c:107)
==7699== 
==7699== 96 bytes in 4 blocks are definitely lost in loss record 12 of 19
==7699==    at 0x4C2DB9D: malloc (vg_replace_malloc.c:299)
==7699==    by 0x403C81: ft_memalloc (in /home/julekgwa/21shell/21sh)
==7699==    by 0x4039E9: ft_strdup (in /home/julekgwa/21shell/21sh)
==7699==    by 0x401CB8: ft_add_value (ft_env.c:27)
==7699==    by 0x401DF8: ft_setenv (ft_env.c:54)
==7699==    by 0x401854: ft_modpwd (ft_cd.c:82)
==7699==    by 0x4019BD: ft_cd (ft_cd.c:113)
==7699==    by 0x400CE1: ft_execute_commands (main.c:41)
==7699==    by 0x4026EE: ft_advanced_com (ft_more_utils.c:68)
==7699==    by 0x400E8F: ft_run_commands (main.c:65)
==7699==    by 0x4013E3: ft_process_cmd (ft_commands.c:86)
==7699==    by 0x4010D9: main (main.c:117)
==7699== 
==7699== 108 bytes in 4 blocks are definitely lost in loss record 13 of 19
==7699==    at 0x4C2DB9D: malloc (vg_replace_malloc.c:299)
==7699==    by 0x403C81: ft_memalloc (in /home/julekgwa/21shell/21sh)
==7699==    by 0x4039E9: ft_strdup (in /home/julekgwa/21shell/21sh)
==7699==    by 0x401CB8: ft_add_value (ft_env.c:27)
==7699==    by 0x401DF8: ft_setenv (ft_env.c:54)
==7699==    by 0x401837: ft_modpwd (ft_cd.c:81)
==7699==    by 0x4019BD: ft_cd (ft_cd.c:113)
==7699==    by 0x400CE1: ft_execute_commands (main.c:41)
==7699==    by 0x4026EE: ft_advanced_com (ft_more_utils.c:68)
==7699==    by 0x400E8F: ft_run_commands (main.c:65)
==7699==    by 0x4013E3: ft_process_cmd (ft_commands.c:86)
==7699==    by 0x4010D9: main (main.c:117)
==7699== 
==7699== LEAK SUMMARY:
==7699==    definitely lost: 255 bytes in 10 blocks
==7699==    indirectly lost: 0 bytes in 0 blocks
==7699==      possibly lost: 0 bytes in 0 blocks
==7699==    still reachable: 15,256 bytes in 16 blocks
==7699==         suppressed: 0 bytes in 0 blocks
==7699== Reachable blocks (those to which a pointer was found) are not shown.
==7699== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==7699== 
==7699== For counts of detected and suppressed errors, rerun with: -v
==7699== Use --track-origins=yes to see where uninitialised values come from
==7699== ERROR SUMMARY: 17 errors from 6 contexts (suppressed: 0 from 0)

无法在C中释放双指针

0 个答案: