Octave's search path contains the following directories:

.                                                        /usr/share/octave/3.6.4/m/prefs
/usr/share/octave/packages/control-2.4.1                 /usr/share/octave/3.6.4/m/special-matrix
/usr/lib64/octave/3.6.4/site/oct/x86_64-pc-linux-gnu     /usr/share/octave/3.6.4/m/set
/usr/lib64/octave/site/oct/api-v48+/x86_64-pc-linux-gnu  /usr/share/octave/3.6.4/m/general
/usr/lib64/octave/site/oct/x86_64-pc-linux-gnu           /usr/share/octave/3.6.4/m/time
/usr/share/octave/3.6.4/site/m                           /usr/share/octave/3.6.4/m/miscellaneous
/usr/share/octave/site/api-v48+/m                        /usr/share/octave/3.6.4/m/pkg
/usr/share/octave/site/m                                 /usr/share/octave/3.6.4/m/startup
/usr/share/octave/site/m/startup                         /usr/share/octave/3.6.4/m/help
/usr/lib64/octave/3.6.4/oct/x86_64-pc-linux-gnu          /usr/share/octave/3.6.4/m/io
/usr/share/octave/3.6.4/m                                /usr/share/octave/3.6.4/m/testfun
/usr/share/octave/3.6.4/m/optimization                   /usr/share/octave/3.6.4/m/linear-algebra
/usr/share/octave/3.6.4/m/image                          /usr/share/octave/3.6.4/m/specfun
/usr/share/octave/3.6.4/m/strings                        /usr/share/octave/3.6.4/m/signal
/usr/share/octave/3.6.4/m/statistics                     /usr/share/octave/3.6.4/m/deprecated
/usr/share/octave/3.6.4/m/statistics/models              /usr/share/octave/3.6.4/m/polynomial
/usr/share/octave/3.6.4/m/statistics/base                /usr/share/octave/3.6.4/m/sparse
/usr/share/octave/3.6.4/m/statistics/distributions       /usr/share/octave/3.6.4/m/plot
/usr/share/octave/3.6.4/m/statistics/tests               /usr/share/octave/3.6.4/m/audio
/usr/share/octave/3.6.4/m/geometry                       /usr/share/octave/3.6.4/m/path
/usr/share/octave/3.6.4/m/elfun