I am writing a small program that is supposed to act as a shell of some sorts. It operates off of a few basic structures, one of them being a command, a command_list, and a command_history.

typedef struct command command;

typedef struct
{
    char** list;
    int len;
} command_history;

typedef struct 
{
    command** list;
    int len;
    command_history* history;
} command_list;

typedef struct command
{
    char* alias;
    void (*function)(command_list*);
} command;

I have written functions to add new commands, add new history, find aliases in a list and return its index, among other things, but I have a feeling that the command for adding commands, addcommand is leaking memory. I am not very experienced with C and this is just an experiment to aquatint me with pointers. I would appreciate some feedback on the code I have written and how I can improve it.

Command manipulation functions:

void addcommand(char* str, void* fun, command_list* srclist)
{
    printdebug("Adding command \"%s\" pointing to function at %p in command list located at %p... ", str, fun, srclist);
    srclist -> list = realloc(srclist -> list, sizeof(command*) * (srclist -> len + 1));
    srclist -> list[srclist -> len] = malloc(sizeof(command));
    srclist -> list[srclist -> len] -> alias = malloc(sizeof(char) * (strlen(str) + 1));
    srclist -> list[srclist -> len] -> function = malloc(sizeof(void*)); // problems here and |
    memcpy(srclist -> list[srclist -> len] -> alias, str, sizeof(char) * (strlen(str) + 1)); //       |
    srclist -> list[srclist -> len] -> function = fun; //                                    <|
    srclist -> len++;
    printdebug("Command added.\n");
}

void addhistory(char* str, command_list* srclist)
{
    printdebug("Adding \"%s\" to history list located at %p...", str, srclist -> history);
    srclist -> history -> list = realloc(srclist -> history -> list, sizeof(char*) * (srclist -> history -> len + 1));
    srclist -> history -> list[srclist -> history -> len] = malloc((strlen(str) + 1) * sizeof(char));
    memcpy(srclist -> history -> list[srclist -> history -> len], str, (strlen(str) + 1) * sizeof(char));
    srclist -> history -> len++;
    printdebug(" String added to history.\n");
}

void renamecommand(char* str, command* srccom, command_list* srclist)
{
    if(!srccom -> alias || !srccom -> function)
        return;
    printdebug("Renaming \"%s\" to \"%s\" in command list located at %p... ", srccom -> alias, str, srclist);
    free(srccom -> alias);
    srccom -> alias = malloc((strlen(str) + 1) * sizeof(char));
    memcpy(srccom -> alias, str, (strlen(str) + 1) * sizeof(char));
    printdebug("Renamed command.\n");
}

void deletecommand(command* srccom)
{
    printdebug("Deleting command \"%s\" pointing to function %p located at %p... ", srccom -> alias, srccom -> function, srccom);
    srccom -> alias = "[REMOVED]";
    srccom -> function = NULL;
    printdebug("Command deleted.\n");
}

command_list* newcommandlist()
{
    printdebug("Making new command list... ");
    command_list* new_list = malloc(sizeof(command_list));
    new_list -> list = NULL;
    new_list -> len = 0;
    new_list -> history = malloc(sizeof(command_history));
    new_list -> history -> list = NULL;
    new_list -> history -> len = 0;
    printdebug(" Made new command list located at %p.\n", new_list);
    return new_list;
}