add stub lif_interface_file_parse()

Makefile

@@ -5,7 +5,8 @@ CFLAGS := -ggdb3 -O2 -Wall -I. -DINTERFACES_FILE=\"${INTERFACES_FILE}\"
 LIBIFUPDOWN_SRC = \
 	libifupdown/list.c \
 	libifupdown/dict.c \
-	libifupdown/interface.c
+	libifupdown/interface.c \
+	libifupdown/interface-file.c
 
 LIBIFUPDOWN_OBJ = ${LIBIFUPDOWN_SRC:.c=.o}
 LIBIFUPDOWN_LIB = libifupdown.a

cmd/ifquery.c

@@ -92,7 +92,11 @@ main(int argc, char *argv[])
 		}
 	}
 
-	lif_interface_collection_init(&collection);
+	if (!lif_interface_file_parse(&collection, interfaces_file))
+	{
+		fprintf(stderr, "ifquery: could not parse %s\n", interfaces_file);
+		return EXIT_FAILURE;
+	}
 
 	if (optind >= argc)
 		usage();
@@ -103,7 +107,7 @@ main(int argc, char *argv[])
 		struct lif_dict_entry *entry = lif_dict_find(&collection, argv[idx]);
 		if (entry == NULL)
 		{
-			printf("ifquery: unknown interface %s\n", argv[idx]);
+			fprintf(stderr, "ifquery: unknown interface %s\n", argv[idx]);
 			return EXIT_FAILURE;
 		}
 

libifupdown/interface-file.c

@@ -0,0 +1,25 @@
+/*
+ * libifupdown/interface-file.h
+ * Purpose: /etc/network/interfaces parser
+ *
+ * Copyright (c) 2020 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include <stdio.h>
+#include "libifupdown/interface-file.h"
+
+bool
+lif_interface_file_parse(struct lif_dict *collection, const char *filename)
+{
+	lif_interface_collection_init(collection);
+
+	return true;
+}

libifupdown/interface-file.h

@@ -0,0 +1,24 @@
+/*
+ * libifupdown/interface-file.h
+ * Purpose: /etc/network/interfaces parser
+ *
+ * Copyright (c) 2020 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#ifndef LIBIFUPDOWN_INTERFACE_FILE_H__GUARD
+#define LIBIFUPDOWN_INTERFACE_FILE_H__GUARD
+
+#include <stdbool.h>
+#include "libifupdown/interface.h"
+
+extern bool lif_interface_file_parse(struct lif_dict *collection, const char *filename);
+
+#endif

libifupdown/libifupdown.h

@@ -19,5 +19,6 @@
 #include "libifupdown/list.h"
 #include "libifupdown/dict.h"
 #include "libifupdown/interface.h"
+#include "libifupdown/interface-file.h"
 
 #endif