update cpio documentation, add basic test of binary format

2 files changed, 9 insertions, 0 deletions

diff --git a/cpio/bsdcpio.1 b/cpio/bsdcpio.1
index 514c1a2c..01b508e1 100644
--- a/cpio/bsdcpio.1
+++ b/cpio/bsdcpio.1
@@ -82,6 +82,13 @@ all operating modes.
 .It Fl 0 , Fl Fl null
 Read filenames separated by NUL characters instead of newlines.
 This is necessary if any of the filenames being read might contain newlines.
+.It Fl 6 , Fl Fl pwb
+When reading a binary format archive, assume it's the earlier one,
+from the PWB variant of 6th Edition UNIX.
+When writing a cpio archive, use the PWB format.
+.It Fl 7 , Fl Fl binary
+(o mode only)
+When writing a cpio archive, use the (newer, non-PWB) binary format.
 .It Fl A
 (o mode only)
 Append to the specified archive.
diff --git a/cpio/test/test_basic.c b/cpio/test/test_basic.c
index b7162534..3d7d86a0 100644
--- a/cpio/test/test_basic.c
+++ b/cpio/test/test_basic.c
@@ -230,6 +230,8 @@ DEFINE_TEST(test_basic)
 	basic_cpio("copy_odc", "--format=odc", "", msg, msg);
 	basic_cpio("copy_newc", "-H newc", "", result, "2 blocks\n");
 	basic_cpio("copy_cpio", "-H odc", "", msg, msg);
+	msg = "1 block\n";
+	basic_cpio("copy_bin", "-H bin", "", msg, msg);
 	msg = canSymlink() ? "9 blocks\n" : "8 blocks\n";
 	basic_cpio("copy_ustar", "-H ustar", "", msg, msg);