+/* Expand %VAR% references. Any unknown vars or unrecognized
+ * syntax leaves the raw chars unchanged. */
+static char *expand_vars(char *str)
+{
+ char *buf, *t, *f;
+ int bufsize;
+
+ if (strchr(str, '%') == NULL)
+ return str;
+
+ bufsize = strlen(str) + 2048;
+ if ((buf = new_array(char, bufsize+1)) == NULL) /* +1 for trailing '\0' */
+ out_of_memory("expand_vars");
+
+ for (t = buf, f = str; bufsize && *f; ) {
+ if (*f == '%' && *++f != '%') {
+ char *percent = strchr(f, '%');
+ if (percent) {
+ char *val;
+ *percent = '\0';
+ val = getenv(f);
+ *percent = '%';
+ if (val) {
+ int len = strlcpy(t, val, bufsize+1);
+ if (len > bufsize)
+ break;
+ bufsize -= len;
+ t += len;
+ f = percent + 1;
+ continue;
+ }
+ }
+ f--;
+ }
+ *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;
+}
+