util: put convenience helpers into util.[ch]

Also introduces get_ncpus(), in preparation for threaded rendering.

1 files changed, 26 insertions, 0 deletions

diff --git a/util.h b/util.h
new file mode 100644
index 0000000..c82b623
--- /dev/null
+++ b/util.h
@@ -0,0 +1,26 @@
+#ifndef _UTIL_H
+#define _UTIL_H
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define exit_if(_cond, _fmt, ...) \
+	if (_cond) { \
+		fprintf(stderr, "Fatal error: " _fmt "\n", ##__VA_ARGS__); \
+		exit(EXIT_FAILURE); \
+	}
+
+#define pexit_if(_cond, _fmt, ...) \
+	exit_if(_cond, _fmt ": %s", ##__VA_ARGS__, strerror(errno))
+
+#define nelems(_array) \
+	(sizeof(_array) / sizeof(_array[0]))
+
+#define cstrlen(_str) \
+	(sizeof(_str) - 1)
+
+unsigned get_ncpus(void);
+
+#endif /* _UTIL_H */