/* Strings and chars in C

A String is a char array with a null (\0) on the end - so you refer to strings by the ADDRESS of
the first element but to chars by their value. And if you use a string function on the address
of a char variable, you'll also be accessing the following memory contents up to and including the
next byte which happens to be null. */

#include <stdio.h>
#include <string.h>

void centred(char *);

int main() {

        char capital = 'A';
        char *company = "Well House Consultants";

        printf ("The letter is %c.\n",capital);
        printf ("The company is %s.\n",company); /* From given address to null */
        printf ("The string is %s.\n",&capital); /* From given address to null */

        printf ("The string is %s.\n",&company[12]); /* From given address to null */

        centred(company);

}

void centred(char * headline) {
        char lyne[81]; /* Allow for 80 + terminating null */

        int insize, newstart;
        int k;

        for (k=0;k<80;k++) lyne[k] = '-';
        lyne[80] = '\0';

        insize = strlen(headline);
        newstart = (80 - insize ) /2;

        strcpy(&lyne[newstart],headline); /* String copy */
                                /* Sorry - if you copy a string with =, you copy the address
                                and you do NOT replicate the string as you might hope!
                                You have to use a function such as strcpy or strncpy (usually better)
                                instead*/

        lyne[newstart+insize] = '@'; /* strcpy has added a null and trucated lyne
                                Replace thet null with what it overwrote */
                                /* (or rather @ for demo purposes only) */

        printf("%s\n",lyne);

        /* lots more such as strncpy and strcmp (beware the return value of that) */

}

/*

munchkin:c12 grahamellis$ ./chout
The letter is A.
The company is Well House Consultants.
The string is A??_?.
The string is onsultants.
-----------------------------Well House Consultants@----------------------------
munchkin:c12 grahamellis$

*/