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#include <stdio.h>
/* The C Programming Language, 2nd Edition
*
* Exercise 5-3: Write a pointer version of the function strcat that we showed
* in Chapter 2: strcat(s,t) copies the string t to the end of s.
*
* Answer: Pay careful attention to the passage before this exercise; there's
* a difference between a character array and a pointer to a string constant.
* The major difference is you can modify the contents of a character array.
* String constants, like other constants, can't be modified. This practically
* requires that the first argument to strcatp is a character array.
*
* When working with pointers, details seem to be of utmost importance.
*
* Thanks to Chris and dagle from Freenode's ##c for their input on
* improving the code.
*/
#define ALLOC 80
void strcatp(char *s, char *t);
int main(void) {
char foo[ALLOC] = "This is amazing!";
char *bar = " Pointers for everyone!";
strcatp(foo, bar);
printf("%s\n", foo);
return 0;
}
/* strcat: copy t into s; s must be large enough */
void strcatp(char *s, char *t) {
while (*s != '\0') {
s++;
}
/* Doing this without checking a buffer means it may screw up memory.
* It's the programmer's duty to ensure this doesn't happen, not the
* function's.
*/
while ((*s++ = *t++));
}
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