1 files changed, 71 insertions, 0 deletions
diff --git a/lib/linux_version.c b/lib/linux_version.c
new file mode 100644
index 0000000..137bbe7
--- /dev/null
+++ b/lib/linux_version.c
@@ -0,0 +1,71 @@
+#include <stdio.h>
+#include <sys/utsname.h>
+
+#include "c.h"
+#include "linux_version.h"
+
+int get_linux_version (void)
+{
+	static int kver = -1;
+	struct utsname uts;
+	int x = 0, y = 0, z = 0;
+	int n;
+
+	if (kver != -1)
+		return kver;
+	if (uname(&uts))
+		return kver = 0;
+
+	n = sscanf(uts.release, "%d.%d.%d", &x, &y, &z);
+	if (n < 1 || n > 3)
+		return kver = 0;
+
+	return kver = KERNEL_VERSION(x, y, z);
+}
+
+#ifdef TEST_PROGRAM_LINUXVERSION
+# include <stdlib.h>
+int main(int argc, char *argv[])
+{
+	int rc = EXIT_FAILURE;
+
+	if (argc == 1) {
+		printf("Linux version: %d\n", get_linux_version());
+		rc = EXIT_SUCCESS;
+
+	} else if (argc == 5) {
+		const char *oper = argv[1];
+
+		int x = atoi(argv[2]),
+		    y = atoi(argv[3]),
+		    z = atoi(argv[4]);
+		int kver = get_linux_version();
+		int uver = KERNEL_VERSION(x, y, z);
+
+		if (strcmp(oper, "==") == 0)
+			rc = kver == uver;
+		else if (strcmp(oper, "<=") == 0)
+			rc = kver <= uver;
+		else if (strcmp(oper, ">=") == 0)
+			rc = kver >= uver;
+		else
+			errx(EXIT_FAILURE, "unsupported operator");
+
+		if (rc)
+			printf("match\n");
+		else
+			printf("not-match [%d %s %d, x.y.z: %d.%d.%d]\n",
+					kver, oper, uver, x, y, z);
+
+		rc = rc ? EXIT_SUCCESS : EXIT_FAILURE;
+
+	} else
+		 fprintf(stderr, "Usage:\n"
+				 "   %s [<oper> <x> <y> <z>]\n"
+				 "supported operators:\n"
+				 "   ==, <=, >=\n",
+				 program_invocation_short_name);
+
+	return rc;
+}
+#endif