#include <stdio.h> 
#include <limits.h> 
#include <signal.h> 
#include <fcntl.h>
#include <unistd.h>
#include <wait.h>
/* mycd */
#include <stdlib.h>
/* mykill */
#include <sys/types.h>
#include <signal.h>
#include <ctype.h>      /* isdigit */
/* myps */            
#include <sys/stat.h>
#include <dirent.h>
#include <string.h>
/* myls */
/* uid lookup */
#include <pwd.h>
/* gid lookup */
#include <grp.h>


#define TRUE 1 
#define FALSE 0
#define OKAY 1
#define ERROR 0
#define MAXLINE 200                  /* Maximum length of input line */
#define MAXARG 20      /* Max number of args for each simple command */
#define PIPELINE 5    /* Max number of simple commands in a pipeline */
#define MAXNAME 100    /* Maximum length of i/o redirection filename */

char line[MAXLINE+1];		            /* User typed input line */
char *lineptr;	            /* Pointer to current position in line[] */
char avline[MAXLINE+1];		   /* Argv strings taken from line[] */
char *avptr;	          /* Pointer to current position in avline[] */
char infile[MAXNAME+1];		       /* Input redirection filename */
char outfile[MAXNAME+1];	       /* Ouput redirection filename */

int backgnd;                   /* TRUE if & ends pipeline else FALSE */
int lastpid;               /* PID of last simple command in pipeline */
int append;            /* TRUE for append redirection (?) else FALSE */

struct cmd
{
  char *av[MAXARG]; 
  int infd; 
  int outfd;
} cmdlin[PIPELINE];	    /* Argvs and fds, one per simple command */

/* simple.c method prototypes */
void initcold(void);
void initwarm(void);
int getline(void);
int parse(void);
void command(int i);
void execute(int j);
void forkexec(struct cmd *ptr);
int check (char *ptr);
int getname(char *name);
/* added */
int builtin(struct cmd *ptr);
void mycd(char **argv);
int mykill(char **argv);
int mypwd(char **argv);
int myps(char **argv);
int myls (char **argv);
/* myls function declarations */
int fullDetails(struct dirent *link, struct stat buf, char current[]);
void sortList(char *list[], int count);
int cmp(const void *s1, const void *s2);