Function expand_vars

loadparm.c:167–211

Expand %VAR% references. Any unknown vars or unrecognized * syntax leaves the raw chars unchanged. */

/* Expand %VAR% references.  Any unknown vars or unrecognized
 * syntax leaves the raw chars unchanged. */
static char *expand_vars(const char *str)
{
	char *buf, *t;
	const char *f;
	int bufsize;

	if (!str || !strchr(str, '%'))
		return (char *)str; /* TODO change return value to const char* at some point. */

	bufsize = strlen(str) + 2048;
	buf = new_array(char, bufsize+1); /* +1 for trailing '\0' */

	for (t = buf, f = str; bufsize && *f; ) {
		if (*f == '%' && isUpper(f+1)) {
			const char *percent = strchr(f+1, '%');
			if (percent && percent - f < bufsize) {
				char *val;
				strlcpy(t, f+1, percent - f);
				val = getenv(t);
				if (val) {
					int len = strlcpy(t, val, bufsize+1);
					if (len > bufsize)
						break;
					bufsize -= len;
					t += len;
					f = percent + 1;
					continue;
				}
			}
		}
		*t++ = *f++;
		bufsize--;
	}
	*t = '\0';

	if (*f) {
		rprintf(FLOG, "Overflowed buf in expand_vars() trying to expand: %s\n", str);
		exit_cleanup(RERR_MALLOC);
	}

	if (bufsize && (buf = realloc(buf, t - buf + 1)) == NULL)
		out_of_memory("expand_vars");

	return buf;
}

/* Each "char* foo" has an associated "BOOL foo_EXP" that tracks if the string has been expanded yet or not. */