fossil: import from plan 9

R=rsc
https://codereview.appspot.com/7988047

1 files changed, 40 insertions, 0 deletions

diff --git a/src/cmd/fossil/last.c b/src/cmd/fossil/last.c
new file mode 100644
index 00000000..21d80811
--- /dev/null
+++ b/src/cmd/fossil/last.c
@@ -0,0 +1,40 @@
+#include <u.h>
+#include <libc.h>
+
+void
+usage(void)
+{
+	fprint(2, "usage: fossil/last disk\n");
+	exits("usage");
+}
+
+void
+main(int argc, char **argv)
+{
+	int fd, bs, addr;
+	char buf[20];
+
+	ARGBEGIN{
+	default:
+		usage();
+	}ARGEND
+
+	if(argc != 1)
+		usage();
+
+	if((fd = open(argv[0], OREAD)) < 0)
+		sysfatal("open %s: %r", argv[0]);
+
+	werrstr("end of file");
+	if(seek(fd, 131072, 0) < 0 || readn(fd, buf, 20) != 20)
+		sysfatal("error reading %s: %r", argv[0]);
+	fmtinstall('H', encodefmt);
+	if(memcmp(buf, "\x37\x76\xAE\x89", 4) != 0)
+		sysfatal("bad magic %.4H != 3776AE89", buf);
+	bs = buf[7]|(buf[6]<<8);
+	addr = (buf[8]<<24)|(buf[9]<<16)|(buf[10]<<8)|buf[11];
+	if(seek(fd, (vlong)bs*addr+34, 0) < 0 || readn(fd, buf, 20) != 20)
+		sysfatal("error reading %s: %r", argv[0]);
+	print("vac:%.20lH\n", buf);
+	exits(0);
+}