Comment by ktRolster

Oh yeah, you're right.

Another thing I've done that will work if you have a lot of strcat(), is make a string struct:

    ktString {
       int len;
       int memlen;
       char *str;
    }

It keeps track of the string's actual length, and the size of the underlying buffer. Then you can 'override' the various string functions:

    bool ktStrcat(ktString s1, ktString s2);
    bool ktSprintf(ktString s1, ...);

These functions will take care of buffer-size checking, and reallocation if necessary. For cases where you need to interface with pre-existing libraries, you can return a cstring(). Make it a function/macro to enable you to change the struct definition in the future:

     #define ktCstr(x) (x)->str

then you can pass it into write() or whatever you need:

    write(sock, ktCstr(s), s->len);