#define _GNU_SOURCE

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

#define WHITESPACE " \t\n" // We want to split our command line up into tokens
// so we need to define what delimits our tokens.
// In this case white space
// will separate the tokens on our command line

#define MAX_COMMAND_SIZE 255 // The maximum command-line size

#define MAX_NUM_ARGUMENTS 30 // Mav shell only supports 30 arguments

#define MAX_CMD_PER_LINE 20 // max number of command per line

/**
* parser the input string to arrays of token
* @param cmd_str
* @param length
* @param working_root
* @return
*/
char ** argument(char * cmd_str, int * length, char **working_root);

/**
* handle ^C and ^Z
* @param signo
*/
void sig_handler(int signo);

/**
* move to other directory
* @param p
* @return
*/
int cd(char * p);

#define MAX_PLIST_SIZE 16
#define MAX_HISTORY_SIZE 50

/**
* run a child process
* @param plist
* @param plist_first
* @param plist_last
* @param token
*/
void runAChild(pid_t *plist, int * plist_first, int * plist_last, char ** token);

/**
* split array of tokens to arrays of smaller commands
* @param token
* @param cmd_num
* @param token_count
* @return
*/
char *** commands(char ** token, int * cmd_num, int token_count);

/**
* main function
* @return
*/
int main() {

// variables
char * cmd_str = (char*) malloc(MAX_COMMAND_SIZE);
int token_count;
char * working_root;
pid_t p;
int status;

// list of process which the program has spawned
pid_t plist[MAX_PLIST_SIZE];
int plist_first = 0;
int plist_last = 0;

// array of entered command
char * history[MAX_HISTORY_SIZE];
int history_next_index = 0;

int cmd_num;

// handle signals
signal(SIGINT, sig_handler);
signal(SIGTSTP, sig_handler);
signal(SIGCHLD, sig

Assignment You are writing an inventory system for a library. Th...