My first shell

shell.c

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/wait.h>

#define MAXS (255)


int main(void) {
  char command[MAXS];
  char * args[MAXS];
  char space[] = " \n";
  while (1) {
    printf("> ");
    fgets(command, MAXS, stdin);
    strtok(command, space);

    if (strcmp(command, "exit")==0) {
      exit(0);
    }

    args[0] = command;
    for (int i=1; i<MAXS; i++) {
      args[i] = strtok(NULL, space);
      if (args[i] == NULL) break;
      *(args[i]-1) = '\0';
    }

    if (fork()==0) {
      int res = execv(command, args);
      if (res != 0) perror("Unable to execute command");
    }
    else {
      int status = 0;
      wait(&status);
      if (status != 0) printf("Non-null return value: %d\n", status);
    }
  } 
  return 0;
}