implement cd command in chdir() system in this code: -

cd: cd always take one argument (0 or >1 args should be signaled as an error). To change directories, use the chdir() system call with the argument supplied by the user; if chdir fails, that is also an error.

code is down below, please implement the chdir() system call using cd command in this code below.

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#include #include #include #include #include

#define MAX_CMD_LENGTH 1024 #define MAX_ARGS 64

char error_message[30] = "An error has occurred ";

int parse_input(char* input, char** args) { int i = 0; char* token = strtok(input, " \t "); while (token != NULL) { args[i++] = token; token = strtok(NULL, " \t "); } args[i] = NULL; return i; }

int execute_cmd(char** args, char** path, int num_paths) { pid_t pid = fork(); if (pid == -1) { write(STDERR_FILENO, error_message, strlen(error_message)); return 1; } else if (pid == 0) { // child process int i; for (i = 0; i < num_paths; i++) { char cmd[MAX_CMD_LENGTH]; snprintf(cmd, sizeof(cmd), "%s/%s", path[i], args[0]); execv(cmd, args); } // if we reach here, execv failed write(STDERR_FILENO, error_message, strlen(error_message)); exit(1); } else { // parent process int status; waitpid(pid, &status, 0); return WEXITSTATUS(status); } }

int main(int argc, char** argv) { // initialize path with /bin char* path[2] = {"/bin", NULL}; int num_paths = 1; // check if we're in batch mode FILE* input_file = NULL; if (argc > 2) { write(STDERR_FILENO, error_message, strlen(error_message)); return 1; } else if (argc == 2) { input_file = fopen(argv[1], "r"); if (input_file == NULL) { write(STDERR_FILENO, error_message, strlen(error_message)); return 1; } } // main loop char* line = NULL; size_t line_size = 0; ssize_t line_len; while (1) { // prompt for input if (input_file == NULL) { printf("wish> "); fflush(stdout); } // read input line_len = getline(&line, &line_size, input_file != NULL ? input_file : stdin); if (line_len == -1) { // end of file or error break; } else if (line_len == 1) { // empty line continue; } else if (strncmp(line, "exit", 4) == 0) { // exit command break; } else { // parse input char* args[MAX_ARGS]; int num_args = parse_input(line, args); // execute command int ret = execute_cmd(args, path, num_paths); if (ret != 0) { printf("Command returned with error code %d ", ret); } // check for exit command if (strcmp(args[0], "exit") == 0) { break; } } // free memory free(line); line = NULL; line_size = 0; } if (input_file != NULL) { fclose(input_file); } return 0; }