[Coco] Converting Dec to Binary

[Mathew Boytim]

 Here is what I thought was an 'interesting' itoa implementation apparently from lwip (Lightweight IP) which I think works for any base from 2 to 36.

Matt
void lwip_itoa(char* result, size_t bufsize, int number){  const int base = 10;  char* ptr = result, *ptr1 = result, tmp_char;  int tmp_value;//  LWIP_UNUSED_ARG(bufsize);
  do {    tmp_value = number;    number /= base;    *ptr++ = "zyxwvutsrqponmlkjihgfedcba9876543210123456789abcdefghijklmnopqrstuvwxyz"[35 + (tmp_value - number * base)];  } while(number);
   /* Apply negative sign */  if (tmp_value < 0) {     *ptr++ = '-';  }  *ptr-- = '\0';  while(ptr1 < ptr) {    tmp_char = *ptr;    *ptr--= *ptr1;    *ptr1++ = tmp_char;  }}

    On Thursday, March 22, 2018, 6:22:26 AM EDT, Barry Nelson <barry.nelson at amobiledevice.com> wrote:  
 
 A number base converter program…
============================

/*    Program to convert Base Numbers    */
/*        J.D.Bowman 08/23/84            */
/*    Translated to UNIX by..........    */
/*            The modem brothers        */
/*    Jorge Lezcano and Barry Nelson    */
#ifdef SYS5
#define index strchr
#endif

#include    <stdio.h>
char        bufin [17] , bufout [17];
char        clear[256];
int        b;
unsigned    i;
char        *type;
void        dechex();
void        hexdec();
void        decbin();
void        bindec();
void        hexbin();
void        binhex();
void        wait();
void        intin();
void        itoh();
void        display();
void        hexin();
unsigned    htoi();
void        itoa();
void        itob();
void        binin();
unsigned    btoi();
extern int tgetent();
extern char *strcpy();
extern size_t strlen();
extern int atoi();
extern void exit();
extern char *index();
extern char *strcat();
extern int fpurge();

int main ()
{
char        val[3];
int        vali ;
char        *getenv();
char        *tgetstr();
char        *term;
char        *point;
char        buff[1024];
int        l;
    term=getenv("TERM");
    if (term==NULL)
        term="dumb";
    tgetent(buff,term);
    point=buff;
    strcpy(clear,tgetstr("cl",&point));
    if (clear[0]!='#')
    {
        l=0;
        while (l<strlen(clear))
            clear[l++] &= 127;
    }
    else
        strcpy(clear,"\f");
    b = 0 ;
    while (b != 2)
    {
        puts(clear);
        printf("  Base Number Conversion by\n          J.D.Bowman");
        printf("\nWritten in 'C' language 08/84");
    printf("\nTranslated to Unix by the modem brothers 1989.");
        printf("\n\n              MENU\n");
        printf("\n        1> Decimal to Hex");
        printf("\n        2> Hex to Decimal");
        printf("\n        3> Decimal to Binary");
        printf("\n        4> Binary to Decimal");
        printf("\n        5> Hex to Binary");
        printf("\n        6> Binary to Hex");
        printf("\n        0> End Session\n");
        printf("\n        Enter Your Choice...");
        fgets(val,2,stdin);
    point=index(val,'\n');
    if (point!=NULL) {
        point='\0';
    }
        vali = atoi(val);
    if (vali == 1)
        {dechex();}
    if (vali == 2)
        {hexdec();}
    if (vali == 3)
        {decbin();}
    if (vali == 4)
        {bindec();}
    if (vali == 5)
        {hexbin();}
    if (vali == 6)
        {binhex();}
    if (vali == 0)
        exit(0);
    if (vali > 6)
        printf("\nMust enter numeric (0 to 6).");
    if (vali > 6) { wait(); }
}
}
void dechex()
{
        type="Decimal to Hex";
        intin();
        i = atoi(bufin);
        itoh(i,bufout);
        display();
        wait();
}
void hexdec()
{
        type="Hex to Decimal";
        hexin();
        i = htoi(bufin);
        itoa(i,bufout);
        display();
        wait();
}
void decbin()
{
        type="Decimal to Binary";
        intin();
        i = atoi(bufin);
        itob(i,bufout);
        display();
        wait();
}
void bindec()
{
        type="Binary to Decimal";
        binin();
        i=btoi(bufin);
        itoa(i,bufout);
        display();
        wait();
}
void hexbin()
{
        type="Hex to Binary";
        hexin();
        i=htoi(bufin);
        itob(i,bufout);
        display();
        wait();
}
void binhex()
{
        type="Binary to Hex";
        binin();
        i=btoi(bufin);
        itoh(i,bufout);
        display();
        wait();
}
void binin()
{
    char        *point;

    fpurge(stdin);
        printf("\nEnter 16 bit Binary number:\n");
        fgets(bufin,16,stdin);
    point=index(bufin,'\n');
    if (point!=NULL) {
        point='\0';
    }
}
void intin()
{
    char        *point;

    fpurge(stdin);
        printf("\nEnter Decimal Integer:\n");
        fgets(bufin,16,stdin);
    point=index(bufin,'\n');
    if (point!=NULL) {
        point='\0';
    }
}
void hexin()
{
    char        *point;

    fpurge(stdin);
        printf("\nEnter Hex Integer:\n");
        fgets(bufin,16,stdin);
    point=index(bufin,'\n');
    if (point!=NULL) {
        point='\0';
    }
}
void display()
{
        printf("\n%s%s",clear,type);
        printf("\nConversion of: ");
        puts(bufin);
        printf("\nEquals : ");
        puts(bufout);
}
void clears()
{        puts(clear);    }
void wait()
{
    fpurge(stdin);
        printf("\nPress <Enter> to continue... ");
        getchar();
}
void itoh(in,buff)
    unsigned in;
    char *buff;
{
        sprintf(buff,"%x",in);
}
unsigned htoi(buff)
    char *buff;
{
        unsigned o;
        sscanf(buff,"%x",&o);
        return(o);
}
void itob(in,buff)
    unsigned in;
    char *buff;
{
        char *bin[16];
        char temp[5];
        char *digits;
        int d;
        int n;
        bin[0]="0000";
        bin[1]="0001";
        bin[2]="0010";
        bin[3]="0011";
        bin[4]="0100";
        bin[5]="0101";
        bin[6]="0110";
        bin[7]="0111";
        bin[8]="1000";
        bin[9]="1001";
        bin[10]="1010";
        bin[11]="1011";
        bin[12]="1100";
        bin[13]="1101";
        bin[14]="1110";
        bin[15]="1111";
        digits="0123456789abcdef";
        strcpy(buff,"");
        sprintf(temp,"%x",in);
        n=0;
        while (n<strlen(temp))
        {
            d=index(digits,temp[n++])-index(digits,'0');
            strcat(buff,bin[d]);
        }
}
unsigned btoi(buff)
    char *buff;
{
        unsigned o;
        int n;
        long p;
        p=1;
        o=0;
        n=strlen(buff)-1;
        while (n>=0)
        {
            if (buff[n--]=='1')
                o+=p;
            p+=p;
        }
        return(o);
}
void itoa(in,buff)
    unsigned in;
    char *buff;
{
        sprintf(buff,"%d",in);
}


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