fixed

libmu/file_open.c

@@ -0,0 +1,16 @@
+#include "file_open.h"
+
+FILE *file_open(const char *prog, const char *path, const char *mode) {
+	if (!strcmp(path, "-"))
+		return stdin;
+
+	FILE *fp = fopen(path, mode);
+	if (fp == NULL) {
+		if (prog)
+			fprintf(stderr, "%s: %s\n", prog, strerror(errno));
+
+		return NULL;
+	}
+
+	return fp;
+}

libmu/file_open.h

@@ -0,0 +1,9 @@
+#ifndef _FILE_OPEN_H
+#define _FILE_OPEN_H
+
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+
+FILE *file_open(const char *prog, const char *path, const char *mode);
+#endif