pamcat(1) on Linux
The text 766f75626d58, as Debian 13 (Trixie) shipped it.
concatenate Netpbm images
Flags it lists
-
-black -
-jbottom -
-jcenter -
-jleft -
-jright -
-jtop -
-leftright -
-listfile -
-lr -
-tb -
-topbottom -
-white