set env var NSXIV_USING_NULL for key-handler and update docs

Co-authored-by: Berke Kocaoğlu <berke.kocaoglu@metu.edu.tr>

1 files changed, 8 insertions, 4 deletions

diff --git a/examples/key-handler b/examples/key-handler
index 6ac754b..7dac1b5 100755
--- a/examples/key-handler
+++ b/examples/key-handler
@@ -3,10 +3,14 @@
 # Example for $XDG_CONFIG_HOME/nsxiv/exec/key-handler
 # Called by nsxiv(1) after the external prefix key (C-x by default) is pressed.
 # The next key combo is passed as its first argument. Passed via stdin are the
-# images to act upon, one path per line: all marked images, if in thumbnail
-# mode and at least one image has been marked, otherwise the current image.
-# nsxiv(1) blocks until this script terminates. It then checks which images
-# have been modified and reloads them.
+# images to act upon: all marked images, if in thumbnail mode and at least one
+# image has been marked, otherwise the current image. nsxiv(1) will block until
+# the handler terminates. It then checks which images have been modified and
+# reloads them.
+
+# By default nsxiv(1) will send one image per-line to stdin, however when using
+# -0 the image list will be NULL separated and the enviornment variable
+# "$NSXIV_USING_NULL" will be set to 1.
 
 # The key combo argument has the following form: "[C-][M-][S-]KEY",
 # where C/M/S indicate Ctrl/Meta(Alt)/Shift modifier states and KEY is the X