how to execute terminal commands in C

i`m trying to simulate a terminal, and in my code almost all commands execute just fine, but the commands cd folder and cd .. when i try to execute those nothing happends, can any one help me with this

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#define MAXLEN 100
#define TRUE 1
#define FALSE 0

typedef struct command {
    char *cmd;              // string apenas com o comando
    struct command *next;   // apontador para o próximo comando
} COMMAND;

COMMAND *insert(COMMAND *list, char *cmd);
COMMAND *startList();
int strCompare(char *str1, char *str2);
int strLenght(char *str);

int main(void) {
    char command[MAXLEN] = "start";
    int id, return_command = 0;
    COMMAND *commands = startList();
    char exit_com[5] = "exit\0";
    int r;
    while(r = strCompare(command, exit_com)){
        char cwd[1024];

        if (getcwd(cwd, sizeof(cwd)) != NULL){
           fprintf(stdout, "%s: ", cwd);
        }

        fgets(command, MAXLEN, stdin);

        commands = insert(commands, command);

        id = fork();
        if (id == 0){
            return_command = system(command);

            if (return_command == -1){
                printf("\nErro ao executar o comando '%s'\n", command);
                exit(0);
            }

            COMMAND *c = commands;

            while(c != NULL){
                printf("%s\n", c->cmd);
                c = c->next;
            }
            exit(0);
        }
        wait(id);
    }
    return 0;
}

int strCompare(char *str1, char *str2){
    char aux = str2[0];
    int i = 0;
    while(aux != '\0'){
        if (str1[i] != str2[i])
            return 1;
        aux = str2[++i];
    }
    return 0;
}

COMMAND *startList(){
    return NULL;
}

COMMAND *insert(COMMAND *list, char *cmd){
    COMMAND *newCommand = (COMMAND*) malloc(sizeof(COMMAND));
    newCommand->cmd = cmd;
    newCommand->next = list;
    return newCommand;
}