=item C<AUG_TYPE_CHECK> = 4
-Typecheck lenses (can be expensive).
+Typecheck lenses.
+
+This option is only useful when debugging Augeas lenses. Use
+of this option may require additional memory for the libguestfs
+appliance. You may need to set the C<LIBGUESTFS_MEMSIZE>
+environment variable or call C<guestfs_set_memsize>.
=item C<AUG_NO_STDINC> = 8
to securely wipe the device). It should be sufficient to remove
any partition tables, filesystem superblocks and so on.
+If blocks are already zero, then this command avoids writing
+zeroes. This prevents the underlying device from becoming non-sparse
+or growing unnecessarily.
+
See also: C<guestfs_zero_device>, C<guestfs_scrub_device>,
C<guestfs_is_zero_device>");
"\
This command writes zeroes over the entire C<device>. Compare
with C<guestfs_zero> which just zeroes the first few blocks of
-a device.");
+a device.
+
+If blocks are already zero, then this command avoids writing
+zeroes. This prevents the underlying device from becoming non-sparse
+or growing unnecessarily.");
("txz_in", (RErr, [FileIn "tarball"; Pathname "directory"], []), 229, [Optional "xz"],
[InitScratchFS, Always, TestOutput (
this normally, because the handle is closed properly when guestfish
exits. However this is occasionally useful for testing.");
+ ("setenv", (RErr,[], []), -1, [], [],
+ "set an environment variable",
+ " setenv VAR value
+
+Set the environment variable C<VAR> to the string C<value>.
+
+To print the value of an environment variable use a shell command
+such as:
+
+ !echo $VAR");
+
("sparse", (RErr,[], []), -1, [], [],
"create a sparse disk image and add",
" sparse filename size
Run the command as usual, but print the elapsed time afterwards. This
can be useful for benchmarking operations.");
+ ("unsetenv", (RErr,[], []), -1, [], [],
+ "unset an environment variable",
+ " unsetenv VAR
+
+Remove C<VAR> from the environment.");
+
]