  In this article we calculate the surface phase diagram of a two-dimensional
hard-rod fluid confined between two hard lines. In a first stage we study the
semi-infinite system consisting of an isotropic fluid in contact with a single
hard line. We have found complete wetting by the columnar phase at the
wall-isotropic fluid interface. When the fluid is confined between two hard
walls, capillary columnar ordering occurs via a first-order phase transition.
For higher chemical potentials the system exhibits layering transitions even
for very narrow slits (near the one-dimensional limit). The theoretical model
used was a density-functional theory based on the Fundamental-Measure
Functional applied to a fluid of hard rectangles in the restricted-orientation
approximation (Zwanzig model). The results presented here can be checked
experimentally in two-dimensional granular media made of rods, where vertical
motions induced by an external source and excluded volume interactions between
the grains allow the system to explore those stationary states which
entropically maximize packing configurations. We claim that some of the surface
phenomena found here can be present in two-dimensional granular-media fluids.
