Why am I getting garbage characters?

Question

I keep getting garbage characters when I am outputing "123" and "0".

I was able to narrow it down to the baseout method, and I believe it may be one of my "for loop" conditions but I can't seem to get to be able to remove the garbage characters.

If you can help, please do. Program is in C.

Thank you in advance.

#include <stdio.h>

#define COUNT 8     /* number of hex digits to display */
#define DECIMAL 10  /* to indicate base 10 */
#define HEX 16      /* to indicate base 16 */

/* array used for ASCII conversion */
const char digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

void baseout (int number, int base, FILE * stream) {
int f1;
int f2;
int index = 0;
int result = number;
char store1[f2];

/*This condition outputs the digit "0" on Line 4*/
if (number == 0) {          
    fputc(digits[0], stream); 
}

/*This condition outputs the digit "0" after "0x"*/
if (base != DECIMAL){
    store1[f1] = '0';
    fputc(store1[f1], stream);

}

/*This condition outputs codes from bases 2-36*/
if (number != 0) {
   for(f2 = 1; f2 < COUNT && result != 0; f2++){
      index = result % base;
      store1[f2] = digits[index];
      result = result / base;
   }
}

for (f2 = COUNT; f2 > 0; f2--){
    fputc(store1[f2], stream);
}
}

void decout (unsigned int number, FILE * stream) {
    /*Passes DECIMAL to baseout algorithm*/
    baseout(number, DECIMAL, stream);    
}

void hexout (unsigned int number, FILE * stream) {

    /* Output "0x" for hexidecimal. */
    writeline ("0x", stream);
    baseout (number, HEX, stream);
}
void newline (FILE * stream) {
    /* Output a newline character */
    fputc('\n', stream);  
}
int writeline (const char * message, FILE * stream) {
    int index = 0;  
    /*While "index<messagelength" output the each character of message*/
    while(message[index] != '\0'){
            fputc(message[index], stream);
        index++;
    }
    /*Return the message length*/
    return sizeof(message); 
}


int main (int argc, char *const* argv) {
    writeline ("Hello World", stdout);
    fprintf (stderr, "Hola Mundo\n");
    newline(stdout);
    decout (123, stdout);
    newline(stdout);
    decout (0, stdout);
    newline(stdout);
    hexout (0xFEEDDAD, stdout);
    newline(stdout);
    return 0;
}

The Desired Output is:

Hola Mundo

Hello World

123

0

0x0FEEDDAD

The Current Output is:

Hola Mundo

Hello World

123

0123

0x0FEEDDAD

Answer 1

This block of code is not well thought out.

    for(f2 = 1; f2 < COUNT; f2++){
        if (result != 0){
            index = result % base;
            store1[f2] = digit[index];
            result = result / base;
        }
    }

You are incrementing f2 even after result is 0 and not setting the value of store1[f2] for those values. Then you go ahead and try to print the contents of store1. Since store1 is not initialized to anything sensible, you are getting garbage.

Here's one way to fix those problems.

/*This condition outputs codes from bases 2-36*/
if (number != 0) {
   for(f2 = 1; f2 < COUNT && result != 0; f2++){
      index = result % base;
      store1[f2] = digits[index];
      result = result / base;
   }               
}

for (f2--; f2 > 0; f2--){
    fputc(store1[f2], stream);
}