/*
  ISH: Incredibly Simple Shell
  
  Author:
  MAT 4970
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

#define MAX_LINE_LENGTH 80               /* upper bounds on line */
#define MAX_ARGUMENTS MAX_LINE_LENGTH/2  /* and number of arguments */

typedef int bool;
#define FALSE 0
#define TRUE 1

void readAndParseArgs(char inputBuffer[], char *args[]);
void displayArgs(char *args[]);

int main(void) {
    char inputBuffer[MAX_LINE_LENGTH + 1];   /* buffer to hold the command entered */
    char *args[MAX_ARGUMENTS + 1];           /* array of arguments */

    while (TRUE) {
	/* Provide a prompt for the command line */
	printf("ISH> ");
	fflush(stdout);   /* force output to appear */

	/* Get a command line */
	readAndParseArgs(inputBuffer, args);

	/* Show the individual arguments */
	displayArgs(args);

	/* Create a child process, execute the specified command,
	   and wait for completion */
    }
}

void readAndParseArgs(char inputBuffer[], char *args[]) {
    int length;   /* number of characters read from the input */
    
    /* get a line of input from the standard input file */
    length = read(STDIN_FILENO, inputBuffer, MAX_LINE_LENGTH + 1);
    if (length == 0) {
	/* EOF encountered... quit the shell */
	printf("exit\n");
        exit(0);
    }
    
    /* Transform the inputBuffer to a C-style string */
    inputBuffer[length - 1] = '\0';
    
    printf("Line entered = \"%s\"\n", inputBuffer);

    /* Isolate the arguments found on the input line and
       store them in the argument vector */
}

void displayArgs(char *args[]) {
    /* Output the arguments in a given argument vector */
}