1 files changed, 60 insertions, 0 deletions
diff --git a/ctdb/common/ctdb_util.c b/ctdb/common/ctdb_util.c
index 137e0a8a09..bd68c55416 100644
--- a/ctdb/common/ctdb_util.c
+++ b/ctdb/common/ctdb_util.c
@@ -64,6 +64,66 @@ void ctdb_die(struct ctdb_context *ctdb, const char *msg)
 	exit(1);
 }
 
+/* Set the path of a helper program from envvar, falling back to
+ * dir/file if envvar unset. type is a string to print in log
+ * messages.  helper is assumed to point to a statically allocated
+ * array of size bytes, initialised to "".  If file is NULL don't fall
+ * back if envvar is unset.  If dir is NULL and envvar is unset (but
+ * file is not NULL) then this is an error.  Returns true if helper is
+ * set, either previously or this time. */
+bool ctdb_set_helper(const char *type, char *helper, size_t size,
+		     const char *envvar,
+		     const char *dir, const char *file)
+{
+	const char *t;
+	struct stat st;
+
+	if (helper[0] != '\0') {
+		/* Already set */
+		return true;
+	}
+
+	t = getenv(envvar);
+	if (t != NULL) {
+		if (strlen(t) >= size) {
+			DEBUG(DEBUG_ERR,
+			      ("Unable to set %s - path too long\n", type));
+			return false;
+		}
+
+		strncpy(helper, t, size);
+	} else if (file == NULL) {
+		return false;
+	} else if (dir == NULL) {
+			DEBUG(DEBUG_ERR,
+			      ("Unable to set %s - dir is NULL\n", type));
+		return false;
+	} else {
+		if (snprintf(helper, size, "%s/%s", dir, file) >= size) {
+			DEBUG(DEBUG_ERR,
+			      ("Unable to set %s - path too long\n", type));
+			return false;
+		}
+	}
+
+	if (stat(helper, &st) != 0) {
+		DEBUG(DEBUG_ERR,
+		      ("Unable to set %s \"%s\" - %s\n",
+		       type, helper, strerror(errno)));
+		return false;
+	}
+	if (!(st.st_mode & S_IXUSR)) {
+		DEBUG(DEBUG_ERR,
+		      ("Unable to set %s \"%s\" - not executable\n",
+		       type, helper));
+		return false;
+	}
+
+	DEBUG(DEBUG_NOTICE,
+	      ("Set %s to \"%s\"\n", type, helper));
+	return true;
+}
+
 /* Invoke an external program to do some sort of tracing on the CTDB
  * process.  This might block for a little while.  The external
  * program is specified by the environment variable