Address out of bounds in C, problems with making an ls command - c

Question

I am trying to make a some what shell in C but I am having problems with making the ls command. mkdir, and cd work fine but with ls it gives me
"Address out of bounds segmentation error"
Hope somebody can help me. Here's my code.
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <readline/readline.h>
#include <unistd.h>
#include <sys/wait.h>
int main() {
printf("\033[1;33mWelcome To Crisp Bacon Shell\n");
while (1) {
printf("\033[0m%s $", hostname);
input = readline("");
command = get_input(input);
child_pid = fork();
if (child_pid < 0) {
perror("Fork failed");
exit(1);
}else if (child_pid == 0) {
/* Never returns if the call is successful */
execvp(command[0], command);
printf("This won't be printed if execvp is successul\n");
} else {
waitpid(child_pid, &stat_loc, WUNTRACED);
}
free(input);
free(command);
}
return 0;
}
char **get_input(char *input) {
char **command = malloc(8 * sizeof(char *));
char *separator = " ";
char *parsed;
int index = 0;
parsed = strtok(input, separator);
while (parsed != NULL) {
command[index] = parsed;
index++;
parsed = strtok(NULL, separator);
}
command[index] = NULL;
return command;
}
The only thing I understand it has something to do with memory and references or pointers but I tried changing everything from & refrencing to pointers and it just gave me more errors what do I do?

Answer 1

There were many undeclared variables in your code snippets. You also need to fetch the hostname, it isn't a global variable. It's also a best practice to declare your functions before using them.
This works fine:
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <readline/readline.h>
#include <unistd.h>
#include <sys/wait.h>
char **get_input(char *input) {
char **command = malloc(8 * sizeof(char *));
char *separator = " ";
int index = 0;
char *parsed = strtok(input, separator);
while (parsed != NULL && index < 8) { // you need to make sure the index does not overflow the array
command[index] = parsed;
index++;
parsed = strtok(NULL, separator);
}
command[index] = NULL;
return command;
}
int main() {
printf("\033[1;33mWelcome To Crisp Bacon Shell\n");
while (1) {
// hostname does not exist, you need to fetch it
char hostname[1024];
gethostname(hostname, 1023); // POSIX only
printf("\033[0m%s $", hostname);
char *input = readline(NULL);
char **command = get_input(input);
pid_t child_pid = fork();
if (child_pid < 0) {
perror("Fork failed");
exit(1);
} else if (child_pid == 0) {
/* Never returns if the call is successful */
execvp(command[0], command);
printf("This won't be printed if execvp is successul\n");
} else {
waitpid(child_pid, NULL, WUNTRACED); // since you don't use the middle argument, no need to point to valid data
}
free(input);
free(command);
}
return 0;
}