# To unbundle, sh this file
echo Makefile 1>&2
cat >Makefile <<'End of Makefile'
O_FILES = monty.o usage.o help.o
CFLAGS = 
CC = gcc

monty:	$(O_FILES)
	$(CC) $(CFLAGS) -o monty $(O_FILES)
End of Makefile
echo help.c 1>&2
cat >help.c <<'End of help.c'
/*
 *  help - give program help
 */

#include        <stdio.h>

help(argv)
char** argv;
{
    fprintf(stderr, "%s: HELP:\n", argv[0]);
    fprintf(stderr, "\n");
    fprintf(stderr, "    monty - template filter\n");
    fprintf(stderr, "\n");
    fprintf(stderr, "    >>> This is where to put some friendly help on the why and wherefore of\n");
    fprintf(stderr, "    this program.  For example:\n");
    fprintf(stderr, "\n");
    fprintf(stderr, "    The program parses its command line flags to read a Boolean, integer\n");
    fprintf(stderr, "    and float into global parameter variables.  If the Debug flag is\n");
    fprintf(stderr, "    selected it writes the values of its parameters to standard error.\n");
    fprintf(stderr, "\n");
    fprintf(stderr, "    It then reads a floating point number and an integer, both in\n");
    fprintf(stderr, "    ASCII text, from standard input and then writes them to standard output,\n");
    fprintf(stderr, "    as text preceded by variable names.\n");
    fprintf(stderr, "\n");

    } /* end of help */
End of help.c
echo monty.c 1>&2
cat >monty.c <<'End of monty.c'
/**
 **   monty - monty hall problem simulation
 ** 
 **  CREATED: 2009.09.10 copied from t_filter
 **
 **/

#include        "monty.h"

main(argc, argv)
int argc;
char** argv;
{
    /* declare functions */

    double atof();

    /* declare local variables */

    int n, m;
    int choice;
    int prize;
    int monty;
    int wins = 0;

    /* initialize global variables (including parameters) */

    defaultParms();
    parseArgs(argc, argv);

    /* initialize local variables */

    /* compute & write */

    for (n = 0; n < NumRuns; n++) {
        prize = rpick(NumDoors);
        choice = rpick(NumDoors);
        if (Switch) {
            if (choice == prize) {
                // if we already have the prize chosen we will switch it away
                do {
                    monty = rpick(NumDoors); // this is the choice Monty offers
                    }
                while (monty == choice); // do until monty != choice
                choice = monty;
            } else {
                // if we don't have the prize chosen we will switch to it
                choice = prize;
            }
        } // end if (Switch)
    if (choice == prize) wins++;
    }

    printf("you won %d out of %d runs, for an avearge of %f\n",
        wins, NumRuns, (double)wins/(double)NumRuns);

    } /* end main */

/*
 *  defaultParms - initialize global variables
 */
int rpick(int choices)
{
    return 1 + (int)((double)random()*(double)choices/(double)MAXRAND);
    }

/*
 *  defaultParms - initialize global variables
 */
defaultParms()
{
    Debug = FALSE;

    NumDoors = 3;
    NumRuns  = 1000;
    Switch = TRUE;

    } /* end defaultParms() */

/*
 *  parseArgs - parse arguments into global variables
 */
parseArgs(argc, argv)
int argc;
char** argv;
{
    int i;

    for (i = 0; i < argc; i++) {
        if (argv[i][0] == '-') {
            switch (argv[i][1]) {
                case 'D' : Debug = TRUE;
                           break;
                case 'h' : help(argv);
                           exit(0);
                           break;
                case 'n' : NumRuns = atoi(&argv[++i][0]);
                           break;
                case 'd' : NumDoors = atoi(&argv[++i][0]);
                           break;
                case 'S' : Switch = TRUE;
                           break;
                case 'u' : usage(argv);
                           exit(0);
                           break;
                default:   fprintf(stderr, "%s: ERROR: illegal flag: %s\n",
                               argv[0], argv[i]);
                           usage(argv);
                           exit(0);
                           break;
                } /* end switch */
            } /* end if */
        } /* end for(i) */
    } /* end parseArgs() */

End of monty.c
echo monty.h 1>&2
cat >monty.h <<'End of monty.h'
/*
 * t_filter.h -- include file for t_filter.c
 */

/* includes */

#include        <stdio.h>
#include        <ctype.h>
#include        <math.h>

/* constants */

#define TRUE        (1)
#define FALSE       (0)

#define MAXRAND     (2147483647)

/* global variables */

/* flag-settable parameters (global variables) */

int Debug;              /* Boolean: TRUE = debug writes */
int Switch;             /* Boolean: TRUE = switch doors */
int NumDoors;
int NumRuns;
End of monty.h
echo usage.c 1>&2
cat >usage.c <<'End of usage.c'
/*
 *  usage - give program usage
 */

#include        <stdio.h>

usage(argv)
char** argv;
{
    fprintf(stderr, "%s: USAGE: %s [flags] < infile > outfile\n",
        argv[0], argv[0]);
    fprintf(stderr, "\n");
    fprintf(stderr, "    flag           meaning                 default\n");
    fprintf(stderr, "    -------------  ----------------------  -------\n");
    fprintf(stderr, "    -D             debug                   FALSE  \n");
    fprintf(stderr, "    -h             help on this program           \n");
    fprintf(stderr, "    -d <int>       NumDoors                3      \n");
    fprintf(stderr, "    -n <int>       NumRuns                 1000   \n");
    fprintf(stderr, "    -S             switch doors always     FALSE  \n");
    fprintf(stderr, "    -u             usage (this message)           \n");
    fprintf(stderr, "\n");

    } /* end of usage */
End of usage.c