🚀 go-pugleaf

ytang@red.crayola.cs.psu.edu (Yuan-Ling Tang) asks about writing a
wrapper around malloc to check its return value and do error recovery if
the allocation fails.  His approach led to the need to write a new
function for each type.

The usual way to solve this problem is probably to use the same type as
malloc, that is `void *' when using Standard C, `char *' otherwise.  You
then get a function similar to this one:

	#include <stdio.h>
	#include <stdlib.h>

	void *my_malloc(size_t size) {
		void *p;

		p = malloc(size);
		if (p == NULL) {
			fprintf(stderr, "can't allocate %lu bytes, "
					"aborting program.\n", 
					(unsigned long) size);
			exit(EXIT_FAILURE);
		}
		return p;
	}

(The above code is untested.  Also note that I printed the error to
stderr, as is customary for error messages, and returned EXIT_FAILURE
instead 0, so that the exit code of the program indicates an error. 
Depending on your application, you may have to change the behaviour when
malloc fails.)

The user will then use my_malloc exactly like malloc, but with no need
to check the return value (if the function returns at all, the value is
valid).  For example:

	struct foo *ptr1, *ptr2;

	ptr1 = my_malloc(sizeof(struct foo));
	ptr2 = my_malloc(sizeof(struct foo));

--
Lars.Wirzenius@helsinki.fi  (finger wirzeniu@klaava.helsinki.fi)