/usr/share/doc/libreadline6/examples/ is in libreadline6-dev 6.3-4ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/doc/libreadline6/examples/Makefile
/usr/share/doc/libreadline6/examples/excallback.c
/usr/share/doc/libreadline6/examples/fileman.c
/usr/share/doc/libreadline6/examples/hist_erasedups.c
/usr/share/doc/libreadline6/examples/hist_purgecmd.c
/usr/share/doc/libreadline6/examples/histexamp.c
/usr/share/doc/libreadline6/examples/manexamp.c
/usr/share/doc/libreadline6/examples/rl-callbacktest.c
/usr/share/doc/libreadline6/examples/rl-fgets.c
/usr/share/doc/libreadline6/examples/rl.c
/usr/share/doc/libreadline6/examples/rlcat.c
/usr/share/doc/libreadline6/examples/rlevent.c
/usr/share/doc/libreadline6/examples/rlptytest.c
/usr/share/doc/libreadline6/examples/rltest.c
/usr/share/doc/libreadline6/examples/rlversion.c