4 files changed, 47 insertions, 4 deletions
diff --git a/common/dl.h b/common/dl.h
new file mode 100644
index 0000000..143b422
--- /dev/null
+++ b/common/dl.h
@@ -0,0 +1,14 @@
+#ifndef _COMMON_DL_H_
+#define _COMMON_DL_H_
+
+#include <dlfcn.h>
+#include "err.h"
+
+inline static void check_dlerror()
+{
+	char *err = dlerror();
+	if (err)
+		error("library error: %s\n", err);
+}
+
+#endif
diff --git a/common/err.h b/common/err.h
index 1dccbf9..b9faf11 100644
--- a/common/err.h
+++ b/common/err.h
@@ -1,5 +1,5 @@
-#ifndef _ERR_H_
-#define _ERR_H_
+#ifndef _COMMON_ERR_H_
+#define _COMMON_ERR_H_
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -14,4 +14,14 @@ static inline void error(const char *format, ...)
 	exit(1);
 }
 
+static inline void syserror(const char *call, FILE *file)
+{
+	perror(call);
+
+	if (file)
+		fclose(file);
+
+	exit(1);
+}
+
 #endif
diff --git a/common/file.h b/common/file.h
new file mode 100644
index 0000000..c5e8036
--- /dev/null
+++ b/common/file.h
@@ -0,0 +1,19 @@
+#ifndef _COMMON_FILE_H_
+#define _COMMON_FILE_H_
+
+#include <stdio.h>
+#include <stdbool.h>
+
+inline static bool file_exists(const char *filename)
+{
+	FILE *f = fopen(filename, "r");
+
+	if (f) {
+		fclose(f);
+		return true;
+	}
+
+	return false;
+}
+
+#endif
diff --git a/common/str.h b/common/str.h
index b0baa37..fc5f587 100644
--- a/common/str.h
+++ b/common/str.h
@@ -1,5 +1,5 @@
-#ifndef _UTIL_H_
-#define _UTIL_H_
+#ifndef _COMMON_STR_H_
+#define _COMMON_STR_H_
 
 #include <stdio.h>
 #include <stdarg.h>