1 files changed, 30 insertions, 0 deletions
diff --git a/usr/kinit/getintfile.c b/usr/kinit/getintfile.c
new file mode 100644
index 0000000..41ba475
--- /dev/null
+++ b/usr/kinit/getintfile.c
@@ -0,0 +1,30 @@
+/*
+ * Open a file and read it, assuming it contains a single long value.
+ * Return 0 if we read a valid value, otherwise -1.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "kinit.h"
+
+int getintfile(const char *path, long *val)
+{
+	char buffer[64];
+	char *ep;
+	FILE *f;
+
+	f = fopen(path, "r");
+	if (!f)
+		return -1;
+
+	ep = buffer + fread(buffer, 1, sizeof buffer - 1, f);
+	fclose(f);
+	*ep = '\0';
+
+	*val = strtol(buffer, &ep, 0);
+	if (*ep && *ep != '\n')
+		return -1;
+	else
+		return 0;
+}