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1718627440 • yesterday at 10:52 AM • 2 replies • view on HN

    char * 
    left_pad (const char * string, unsigned int pad)
    {
        char tmp[strlen (string)+pad+1];
        memset (tmp, ' ', pad);
        strcpy (tmp+pad, string);
        return strdup (tmp);
    }
Doesn't sound too hard in my opinion. This only works for strings, that fit on the stack, so if you want to make it robust, you should check for the string size. It (like everything in C) can of course fail. Also it is a quite naive implementation, since it calculates the string size three times.

Replies

brabel • yesterday at 12:05 PM

Not a C expert but you’re using a dynamic array right on the stack, and then returning the duplicate of that. Shouldn’t that be Malloc’ed instead?? Is it safe to return the duplicate of a stack allocated array, wouldn’t the copy be heap allocated anyway? Not to mention it blows the stack and you get segmentation fault?

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newsoftheday • yesterday at 4:36 PM

strndup would be safer if I correctly recall from my C days?

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