Is this all numbers?

How do i find out if argv[1] is all numbers?

Loop through it, seeing if the characters are in the range '0' to '9'. You may need to include '-' for the first character.

Could you supply some code?

Ok this is what i came up with but it doesnt seem to work...

Code:

---

int Digit(char * test)
{
        for(int i = 0; i > strlen(test); i++)
        {
                if(isdigit(test[i]) == 0)
                {
                        return 1;
                }
        }

        return 0;
}

---

Think you lost your [ i ] there.

I think it was meant to be like this:

Code:

---

int Digit(char * test)
{
        for(int i = 0; i > strlen(test); i++)
        {
                if(isdigit(test[ i ]) == 0)
                {
                        return 1;
                }
        }

        return 0;
}

---

I had the i their, but it made it italics instead.

Try this:

Code:

---

bool Digit(char *test) {
    for(int j = 0; j < strlen(test); j++) {
        if(isdigit(test[j]) == 0) {
            return true;
        }
    }

    return false;
}

---

I think you got your comparison mixed up between > and <.

I thought I'd try out my asm skills on this one, try this

Code:

---

bool StringNumeric(char* MyString)
{
        __asm
        {
                push ebx
                push ecx
                push ax


                mov ax, 0x2dfe        ;ah = '-' al = ('.' - 0x30)
                mov ebx, MyString
                mov ecx, 0                ;ch must be zero for the jcxz instruction to work (ecx is 0 as we must add it to ebx)

                sub ah, [ebx]        ;subtract the first character from ah (so ah = 0 if the string begins with a '-')
                sete cl                        ;if the 1st character is '-' ecx = 1, else ecx = 0
                add ebx, ecx        ;adds ecx to ebx
               

loopstrt:

                mov cl, [ebx]        ;store the curren character in cl
                inc ebx                        ;move to the next character
                jcxz stringfinished                ;if we find a null char exit the loop

                sub cl, 0x30        ;cl should be between 30 and 39, so subtract 30 and check it's below 9
                cmp cl, 9
                jb loopstrt

                sub al, cl                ;compare cl to al (true if cl was '.' originally, set al to 0 if true
                jz loopstrt        ;(if it's false al could be anything but we return false anyway

stringfinished:
                pop ax

                cmp cl, 0        ;if cl = 0 return true else return false
                sete al               

                pop cx
                pop ebx
        }
}

---

i reckon that's probably the fastest way of doing it.