Add simple lseek() test on a standard file. Standard it runs on the

/var/log/messages file wich is most likely not interesting but the
regression test can work on every specified filingsystem by passing a file
on that filingsystem to it as argument.

It tests:
- initial position
- seeking absolute position
- seeking end
- seeking negative relative position

more can be added later.

regress/sys/fs/Makefile

@@ -1,5 +1,5 @@
-#	$NetBSD: Makefile,v 1.5 2005/12/19 17:50:02 rpaulo Exp $
+#	$NetBSD: Makefile,v 1.6 2006/09/21 01:27:32 reinoud Exp $
 
-SUBDIR= mkdir getdents posix_fadvise tmpfs
+SUBDIR= mkdir getdents posix_fadvise tmpfs lseek
 
 .include <bsd.subdir.mk>

regress/sys/fs/lseek/Makefile

@@ -0,0 +1,15 @@
+#	$NetBSD: Makefile,v 1.1 2006/09/21 01:27:32 reinoud Exp $
+
+NOMAN=	# defined
+
+PROG=	lseek
+
+regress: ${PROG}
+	@set -e; \
+	if ./${PROG} /var/log/messages > /dev/null; then \
+		echo PASSED; exit 0; \
+	else \
+		echo FAILED; exit 1; \
+	fi
+
+.include <bsd.prog.mk>

regress/sys/fs/lseek/lseek.c

@@ -0,0 +1,70 @@
+#include <stdio.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/unistd.h>
+
+int main(int argc, char **argv)
+{
+	int fd;
+	off_t cur;
+	struct stat st;
+	int error;
+
+	if (argc != 2) {
+		printf("seektest filename\n");
+		return EXIT_FAILURE;
+	}
+	fd = open(argv[1], 0, O_RDONLY);
+	if (fd <= 0) {
+		printf("can't open `%s` : %s\n", argv[1], strerror(errno));
+		return EXIT_FAILURE;
+	}
+
+	error = fstat(fd, &st);
+	if (error) {
+		printf("can't stat file\n");
+		return EXIT_FAILURE;
+	}
+
+	if (st.st_size < 1500) {
+		printf("can't run this test on such a small file\n");
+		return EXIT_FAILURE;
+	}
+
+	printf("get initial position\n");
+	cur = lseek(fd, 0, SEEK_CUR);
+	printf("seek start %d\n", cur);
+	if (cur != 0) {
+		printf("seek initial position wrong\n");
+		return EXIT_FAILURE;
+	}
+
+	printf("seek set 1000\n");
+	cur = lseek(fd, 1000, SEEK_SET);
+	printf("seek now %d\n", cur);
+	if (cur != 1000) {
+		printf("seek 1000 went wrong\n");
+		return EXIT_FAILURE;
+	}
+
+	printf("seeking end (filesize = %d)\n", (uint32_t) st.st_size);
+	cur = lseek(fd, 0, SEEK_END);
+	printf("seek now %d\n", cur);
+	if (cur != st.st_size) {
+		printf("seek to the end went wrong\n");
+		return EXIT_FAILURE;
+	}
+
+	printf("seeking backwards filesize-150 steps\n");
+	cur = lseek(fd, -(st.st_size - 150), SEEK_CUR);
+	printf("seek now %d\n", cur);
+	if (cur != 150) {
+		printf("relative seek from end to 150 failed\n");
+		return EXIT_FAILURE;
+	}
+
+	return EXIT_SUCCESS;
+}
+