ENGR 121 Programming Section 03 Fall 15: 2015

Monday, December 14, 2015

server.c - Dr. Mayhew 12/14/2015

#include <sys/types.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <netdb.h>
#include <stdio.h>

char    db[100][1000000];

void    error    (const char*    msg)    {perror(msg); exit(0); }

const    int    BUF_SIZE    = 1024;
char    db[100][1000000];

int
lookup (
    int    m,
    int    u
) {
    return db[m][u];
}

void
insert (
    int    m,
    int    u
) {
    db[m][u]    = 1;
}

void
delete (
    int    m,
    int    u
) {
    db[m][u]    = 0;
}

void
db_load (
) {
    FILE*    q;
    int        m;
    int        u;

    q    = fopen("george", "r");
    if (q) {
        while(fscanf(q, "%d %d", &m, &u) != EOF) {
            if ((m < 100) && (u < 1000000)) {
                insert(m, u);
            }
        }
        fclose(q);
    }
}

void
db_store (
) {
    FILE*    q;
    int        i;
    int        j;

    q    = fopen("george", "w");
    for (i = 0; i < 100; ++i) {
        for (j = 0; j < 1000000; ++j) {
            if (lookup(i, j))    fprintf(q, "%d %d\n", i, j);
        }
    }
    fclose(q);
}

int
main (
    int        argc,
    char*    argv[]
) {
   int                    sock;
   int                    length;
   int                    n;
   socklen_t            fromlen;
   struct sockaddr_in    server;
   struct sockaddr_in    from;
   char                    buf[BUF_SIZE];
   char                    buffer[BUF_SIZE];

    int        m;
    int        u;
    int        ok;

   if (argc != 2)    error("ERROR, no port provided\n");

   sock        = socket(AF_INET, SOCK_DGRAM, 0);
   if (sock < 0) error("Opening socket");

   length    = sizeof(server);
   bzero(&server, length);
   server.sin_family        = AF_INET;
   server.sin_addr.s_addr    = INADDR_ANY;
   server.sin_port            = htons(atoi(argv[1]));

   if (bind(sock,(struct sockaddr *)&server,length) < 0) error("binding");
   fromlen    = sizeof(struct sockaddr_in);
   db_load();
   for (;;) {
           ok    = 0;
        n    = recvfrom(sock, buf, BUF_SIZE, 0, (struct sockaddr *)&from, &fromlen);
        if (n < 0) error("recvfrom");

        buf[n] = 0;
        sscanf(buf + 2, "%d %d", &m, &u);
        if (m > 99) {
            if (u > 1000000)    ok    = 5;
            else                ok    = 3;
        }
        else if (u > 1000000)    ok    = 4;
        else {
            switch (buf[0]) {
                case 'I':
                    insert(m, u);
                    db_store();
                    break;
                case 'D':
                    delete(m, u);
                    db_store();
                    break;
                case 'L':
                    ok    = !lookup(m, u);
                    break;
                default:
                    ok    = 2;
            }
        }
        buffer[0] = '0' + ok;
        n    = sendto(sock, buffer, 1, 0, (struct sockaddr *)&from, fromlen);
       if (n < 0) error("sendto");
   }
}

Sunday, December 13, 2015

Dr. Mayhew's Keypad Program - 12/12/2015

#include <stdio.h>
#include <stdlib.h>
#include <wiringPi.h>

void
blink(){

    digitalWrite(0,1);
    delay(300);
    digitalWrite(0,0);

}

char
get_key(){

    int        i;
    int        j;

    for (j = 21; j < 25; ++j) {
        digitalWrite(j, 1);
    }
    for (;;) {
        for (i = 25; i < 29; ++i) {
            if (digitalRead(i))    {
                for (j = 21; j < 25; ++j) {
                    digitalWrite(j, 0);
                    if (!digitalRead(i)) {
                        blink();
                        switch (((i - 25) << 2) | (j - 21)) {
                            case 0: return '1';
                            case 1: return '4';
                            case 2: return '7';
                            case 3: return 'C';
                            case 4: return '2';
                            case 5: return '5';
                            case 6: return '8';
                            case 7: return '0';
                            case 8: return '3';
                            case 9: return '6';
                            case 10: return '9';
                            case 11: return '#';
                            case 12: return 'A';
                            case 13: return 'B';
                            case 14: return 'C';
                            case 15: return 'D';
                        }
                    }
                }
            }
        }
    }
}

int
get_num (
    int count,
    int x
){
    char    k;

    printf("in get number");

    while(count){
        printf ("\ncount = %d", count);
        k = get_key();
        printf ("key = %c\n", k);
        if (k == '#') return x;
        if (('0' <= k) && (k <= '9')){
            x    = (x * 10) + (k - '0') ;
        }
        else return -1;
        --count;
        }

    k = get_key();
    if (k == '#') return x;
    else return         -1;
    }

int
main()
{
    int     a;
    int     i,j;
    int     x,y,z;
    int     count;

    wiringPiSetup();

    pinMode(21, OUTPUT);
    pinMode(22, OUTPUT);
    pinMode(23, OUTPUT);
    pinMode(24, OUTPUT);
    pinMode(25, INPUT);
    pinMode(26, INPUT);
    pinMode(27, INPUT);
    pinMode(28, INPUT);

    pinMode(0, OUTPUT);

    x = get_num( 6,0 );
    printf("\nthe number = %d\n" , x );

}

Friday, December 4, 2015

Database db.c - 12/02/2015 Dr.Mayhew

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

char    db[100][1000000];

int
lookup (
    int    m,
    int    u
) {
    return db[m][u];
}

void
insert (
    int    m,
    int    u
) {
    db[m][u]    = 1;
}

void
delete (
    int    m,
    int    u
) {
    db[m][u]    = 0;
}

void
db_load (
) {
    FILE*    q;
    int        m;
    int        u;

    q    = fopen("george", "r");
    if (q) {
        while(fscanf(q, "%d %d", &m, &u) != EOF) {
            if ((m < 100) && (u < 1000000)) {
                insert(m, u);
            }
        }
        fclose(q);
    }
}

void
db_store (
) {
    FILE*    q;
    int        i;
    int        j;

    q    = fopen("george", "w");
    for (i = 0; i < 100; ++i) {
        for (j = 0; j < 1000000; ++j) {
            if (lookup(i, j))    fprintf(q, "%d %d\n", i, j);
        }
    }
    fclose(q);
}

int
main (
) {
    FILE*    q;
    int        m;
    int        u;
    int        i;
    int        j;

    db_load();
    insert(59, 600);
    insert(59, 700000);
    for (i = 0; i < 100; ++i) {
        for (j = 0; j < 1000000; ++j) {
            if (lookup(i, j))    printf("%d %d\n", i, j);
        }
    }
    db_store();
}

Monday, November 23, 2015

Raspberry Pi 2B J8 Header

LEDS ON, LEDS OFF, Push Button Switch, Keypad Programs for the Pi 2B using WiringPi

LEDS ON, LEDS OFF, Push Button Switch, Keypad Programs for the Pi 2B using WiringPi

https://www.dropbox.com/s/3qf3n9b1yvl29br/leds_onEx.c?dl=0

https://www.dropbox.com/s/jdt9lrpbne1k9f4/leds_offEx.c?dl=0

https://www.dropbox.com/s/x3uosnxj2i28bdb/button.c?dl=0

https://www.dropbox.com/s/y38v7dium18siqt/keypad2.c?dl=0

http://pcbheaven.com/wikipages/How_Key_Matrices_Works/