Thread: char strings make me mad

why did they make chars so hard to use? first it has to be constant, or a pointer, then there are terminating NULLs, differing quotes, arrgggggh!!!

im making my own input routine, and everything is working except when 12 or more characters are entered. then when the final value is printed out at the end, it displays a version of the string where some of the characters are missing. eg, if you enter "01234567890", it displays the same, but "012345678901" returns an empty string! anything above 12 starts displaying weird strings, containing the correct characters but all messed up.

here is some code:

Code:

char *temp;
char *temp1;

temp1="";
temp="";

that is the temp string where the inputed characters are added one by one, and another temp string to take the getch().

Code:

temp1[0]=getch();

if (key is not an 'enter' or similar)

    dispText(temp1,font,sx,sy); //this routine just displays text 
    temp[len]=k; //len is current string length
    len++;           //increment len
    temp[len]=0; // set terminator
    sx+=6;          //graphics stuff;
    break;

that code is for when a character is valid and is to be displayed and added to the temp string.

im not sure but i think that its in that last bit of code where the error is. is there some rule of strings where you can only have 12 characters or something?

> temp[len]=k; //len is current string length
> len++; //increment len
> temp[len]=0; // set terminator

why are you assigning the char to the last character of the array?

len is the string length

but chars start from index 0

so if my string length is 4, the array goes char[0],char[1],char[2],char[3]. therefore, char[len] points to the space where the terminator is, or rather, the next available space for an inputed char to go.

with that in mind, can you try and solve the other problems?

can do

i'll send the whole routine:

Code:

char *txtInput(int sx,int sy,FONT font)
{
    char *temp1;
    char *temp;
    int i,j,k;
    int keyGroup;
    int xVal;
    int len;

    setVGA();
    temp1="0";
    temp="";

    len=0;
    xVal=0;

    while (!xVal)
    {
        while (1)
        {
            k=getch();
            if ( (k >= 97) && (k <= 122) )
            {
                keyGroup=1;
                break;
            }

            if ( (k >= 65) && (k <= 90) )
            {
                keyGroup=2;
                break;
            }

            if ( (k >= 48) && (k <= 57) )
            {
                keyGroup=3;
                break;
            }

            if (k==13)
            {
                keyGroup=4;
                break;
            }

            if (k==8)
            {
                keyGroup=5;
                break;
            }
        }

        temp1[0]=k;

        switch (keyGroup)
        {
            case 1:
            case 2:
            case 3:
                dispText(temp1,font,sx,sy);
                temp[len]=k;
                len++;
                temp[len]=0;
                sx+=6;
                break;

            case 4:
                xVal=1;
                break;

            case 5:
                if (len==0) break;
                sx-=6;
                Wipe(sx,sy,5,8);
                temp[len]=0;
                len--;
                break;
        }
    }

    return temp;

}

thats it. ill explain some of the functions:

'Wipe' blacks out a triangle on the screen(this is mode 13)
'dispText' displays a string at a certain point in a certain font

if you know a better way of taking an input from getch(), then adding it to a temporary string, forget about my code and tell me!

thanks moi, your link helped
it seems that it is important to declare a certain size for this purpose.

dog, dont waste your time pouring over my code